bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Iso‐Carbic Metabolic Acidosis in Blood on [H+] and [HCO3‐] in CSF with Deductions about the Regulation of an Active Transport of H+/HCO3 ‐ between Blood and CSF
Authors: Mines A. H. , Morril C. G. , Sørensen S. C.
Published: December 2008

The changes in pH and [HCO3] in csf of anesthetized, paralyzed dogs during metabolic acidosis were compared with those changes when the blood acid‐base parameters were tept at a normal level. Arterial and csf Pco2 were kept constant at the same level during both kinds of experiments. Arterial [HCO3‐‐] was kept cmstant at about 25 meq/l during normal acid‐base experiments and at about 19 meq/l during acidosis experiments. Arterial and csf samples were simultaneously withdrawn after 1 hr, 3 hrs, and 6 hrs. The changes in csf pH and [HCO3‐‐] were expressed as the changes in the electrochemical potential differences (csf‐blood) for H+‘ and HCO3‐ During metabolic acidosis the electrochemical potential differences for H+ and HCO3‐ decreased which could be explained by a decrease in the rate of an active transport of H+/HCO3‐‐ between blood and csf during metabolic acidosis at a constant Pco2. The findings are compared with previous findings and we conclude that the rate of active transport of H+/HCO3‐ between blood and csf if affected by changes in plasma [HCO3‐]. This mechanism provides pH stability in the brain environment during metabolic blood acid‐base changes, whereas the effect is opposite during respiratory acid‐base changes. The mechanism is however “useful” during respiratory acidosis because it provides a negative feed‐back mechanism for the increase in Pco2 during respiratory acidosis.
Vascular and Lipolytic Responses in Canine Subcutaneous Adipose Tissue Following Infusion of Catecholamines
Authors: Ballard Kathryn , Cobb Cully A. , Rosell Sune
Published: December 2008

The aim of the present study was to evaluate the vascular and lipolytic effects of circulating catecholamines in canine subcutaneous adipose tissue. Adrenaline, noradrenaline or isoprena‐line were added at constant rate to the arterial blood supplying subcutaneous adipose tissuein situ. Concentrations of added catecholamine ranged from 10‐‐3to 10‐‐1μg/ml plasma. Blooc/ flow and the net release of glycerol were determined. Adrenaline and noradrenaline were both vasoconstrictor at concentrations above 1 × 10‐‐2μg/ml plasma but differed in the character of the response. Occasionally vasodilatation was observed during infusion of both noradrenaline and adrenaline. Isoprenaline caused vasodilatation at 1 × 10‐‐2μg/ml. Glycerol output was enhanced concomitantly with the vascular responses. The concentration of added noradrenaline (5 × 10‐‐2μg/ml) required to elicit a significant increase in the net release of glycerol exceeded plasma levels reported to be present in resting dogs. It appeared that blood‐borne catecholamines were not as effective for lipolysis as activity in sympathetic nerves to subcutaneous adipose tissue. However, during bleeding or other extreme forms of stress the plasma catecholamine levels may be high enough to induce vasomotor as well as lipolytic responses in subcutaneous adipose tissue.
Metabolism of14C‐Histamine in Domestic Animals
Authors: Eliassen K. A.
Published: December 2008

The metabolism of14C‐histamine injected i.v. in goats has been studied previously. The present study was undertaken to examine whether the metabolic pattern of14C‐histamine found in goats is characteristic for ruminating species. The urinary14C‐metabolites of i.v. injected14C‐his‐tamine to cows and sheep were quantitated by means of isotope dilution technique and paper chromatography. During the first week after injection 74–84 % and 93–99 % of the injected radioactivity was found in sheep and cow urine, respectively. Only 1 % of the radioactivity could be accounted for in the feces and less than 0.03 % in the cow milk. Known metabolites accounted for 84–91 % and 97 % of the urinary radioactivity for sheep and cow, respectively. The metabolic pattern for14C‐histamine degradation in sheep and cow did not differ much. As in goats, the oxidative deamination of histamine to imidazoleacetic acid and imidazoleacetic acid riboside seemed to be the only pathway of quantitative importance. Both in sheep and cows histaminol was found to be a metabolite of i.v. injected14C‐histamine accounting for about 2 % of the urinary radioactivity. In cows the specific radioactivity of histamine was found to be up to 24 times larger than that for 1.4 methylimidazoleacetic acid.
Failure of High Pco2 in the Duodenal Bulb to Inhibit Gastric Acid Secretion
Authors: Nilsson Göran , Rune Simon J.
Published: December 2008

Gastric acid secretion was stimulated by intravenous infusion of pentagastrin (ICI 50 123) in dogs with Pavlov pouches and isolated pouches of the duodenal bulb. Elevation of the Pco2 to 150 or 700 mm Hg in the bulbar pouches did not reduce the gastric acid output. It is suggested that the high CO2 tension which normally exists in the canine duodenum during periods of stimulated gastric acid secretion is not involved in the activation of the bulbar mechanism inhibiting the gastric acid secretion.
Histamine Release from Rat Peritoneal Mast Cells and Cat Paws Induced by Some Neuromuscular Blocking Agents
Authors: Frisk‐Holmberg M. , Strandberg K.
Published: December 2008

The capacity of some neuromuscular blocking agents to release histamine from rat peritoneal mast cells and cat paws has been investigated. Only nondepolarizing agents were effective in the concentration ranges used. The order of potency was tubocurarine, dimethyltubocurarine, toxiferine‐C, alcuronium, in contrast to published data on their corresponding order of neuromuscular blocking activity. In addition to histamine release, tubocurarine and dimethyltubocurarine induced the efflux of slow reacting substance (SRS) from perfused cat paws. The release evoked by tubocurarine or dimethyltubocurarine was reduced by potassium cyanide and lack of Ca++. It is concluded that the interonium distance in neuromuscular blocking agents may be critical for histamine releasing capacity.
The Distribution of 15‐Hydroxy Prosta‐glandin Dehydrogenase and Prostaglandin‐Δ13‐Reductase in Tissues of the Swine
Authors: ÄNggård Erik , Larsson Carin , Samuelsson Bengt
Published: December 2008

Prostaglandin dehydrogenase (15‐hydroxy prostanoate oxidoreductase, EC 1.1.1 (PGDH) and prostaglandin‐Δ13‐reductase (prostanoate Δ13‐oxidoreductase) were assayed in homogenates of 15 different tissues of the swine. Both enzymes were located mainly in the particle free fraction. The highest activities for PGDH were found in the lung, spleen and kidney, which ranged from 50–82 mU/g of tissue or from 482 to 808 m/g of protein. Lower activities of PGDH were observed in the stomach, testicle, liver and small intestine. The renal cortex contained about three times more PGDH than the medulla. The reductase was most abundant in spleen, kidney, liver, adrenal and small intestine, which ranged between 27–38 mU/g of tissue or 232–390 mU/g of protein. The highest specific activity was however found in adipose tissue which contained 3383 mU/g of protein. The wide distribution of these enzymes as well as other evidence support the concept that they catalyze the initial reactions in the metbolism of the prostaglandins.
Histochemical Demonstration of Carbonic Anhydrase Activity in the Rat Kidney
Authors: Lönnerholm Gudmar
Published: December 2008

Lönnerholm, G. Histochemical demonstration of carbonic anhydrase activity in the rat kidney. Acta physiol. scand. 1971. 81. 433–439.

The carbonic anhydrase activity in the kidney of male Sprague‐Dawley rats was studied by a histochemical technique. Enzyme activity was found not only in the proximal and distal tubules, but also in the thin segment of Henle's loop and in the collecting tubules. The arched collecting tubules in the outer cortical zone of the kidney are known to consist of two kinds of cells, the so called light and dark cells. When stained for carbonic anhydrase activity, the arched collecting tubules showed a very distinct staining pattern, with some cells heavily stained and other cells weakly stained. This is of special interest in view of the fact, that other investigators have found an increase in the number of the so called dark cells after administration of sodium or potassium bicarbonate to rats.
Inhibitory Control of the Abdominal Stretch Receptors of the Crayfish
Authors: Jansen J. K. S. , Njå A. , Ormstad K. , Walløe L.
Published: December 2008

Jansen, J. K. S., A. Njå, K. Ormstad and L. Walløe, Inhibitory control of the abdominal stretch receptors of the crayfish. III. The accessory reflex as a recurrent inhibitory feed‐back. Acta physiol. scand. 1971. 81. 472–483.

The autogenetic activation of the thick accessory fibre of the stretch recepton has been examined by intracellular recording and excitation of reflexly intact recepton. The steady‐state effect of this recurrent inhibitory feed‐back is to decrease the sensitivity of the receptor over its entire working range. The closed loop effect can be predicted from the mechanism of the inhibitory action and. the central coupling of the reflex. The effect of the feed‐back can be reversed by increased internal chloride concentration in the receptor. Some time‐dependent properties of the responses of the feed‐back loop are described.
Inhibitory Control of the Abdominal Stretch Receptors of the Crayfish
Authors: Jansen J. K. S. , Njå A. , Ormstad K. , Walløe L.
Published: December 2008

Jansen, J. K. S., A. Njå, K. Ormstad and L. Walløe, Inhibitory control of the abdominal stretch receptors of the crayfish. IV Qbantitative description of the central coupling of the accessory reflex. Acta physiol. scand. 1971. 81. 484–491.

The two accessory neurones have been reflexly activated from neighbouring ipsilateral stretch receptors. The firing frequencies of both increase with increasing input frequencies up to a saturation level which was higher for the thick accessory neurone. Inputs from different segments are summated. The frequency response of the reflex activation of the large accessory neurone has a maximal gain between 2 and 5 Hz. This is within the frequency range of normal movements.
Increase in Capillary Filtration Rate Resulting from Reduction in the Intravascular Calcium Ion‐Concentration
Authors: Nicolaysen G.
Published: December 2008

Nicolaysen, G. Increase in capillary filtration rate resulting from reduction in the intravascular calcium ion‐concentration. Acta physiol. scand. 1971. 81. 517–527.

Marked reductions in intravascular concentrations of Ca++ and Mg++ has previously been shown to cause edema development. The effect of moderate reductions in the intra‐vascular concentration of Ca++ on the net rate of filtration from a vascular bed during increased capillary pressure has been analyzed. Isolated, ventilated rabbit lungs were perfused with plasma at 2° C. In each preparation repeated filtration tests were performed by standardized increases in the outflow pressure lasting for 6 or 10 min. The rate of weight increase for the preparation when 4 min of a test had elapsed was taken as the net rate of filtration. This net rate of filtration was shown to be increased when the [Ca++] was reduced to about 0.1 mM. This increase in filtration rate could be reversed by Ca++‐addition, but not by Mg++‐addition. Evidence is presented that this increase in filtration rate was due to changes in the “hydraulic conductivity” of the capillary wall.
Effects of Variations in the Extracellular Osmolality on the Permeability to Nonelectrolytes of Vascular Smooth Muscle
Authors: Jonsson Olof
Published: December 2008

Jonsson, O., Effects of variations in the extracellular osmolality on the permeability to non‐electrolytes of vascular smooth muscle. Acta physiol. scand. 1971. 81. 528–539.

The effects of variations in the osmolality on the general permeability properties of the smooth muscle cell membranes have been studied by measuring the effluxes of 14C urea and 14C erythritol from rat portal veins at different extracellular tonicities. Permeability coefficients were calculated by introducing the rate constants for the cellular component of the washout curve as well as the estimated cell volume – cell surface ratios into a modified Fick's law of diffusion. The values obtained at normal tonicity of the washout medium were 8.78 10‐8 cm/sec for urea and 3.70 10‐8 cm/sec for erythritol. No definite alteration in the rate‐limiting properties of the cell membranes could be registered on exposure to hyperosmotic or moderately hypo‐osmotic (–54 mOsm/kg) media. However, when the tonicity of the washout medium was more markedly reduced (–109 mOsm/kg) a clearcut increase in the permeability coefficients for both substances was obtained. Possible explanations to this alteration in the permeability characteristics of the cell membranes on swelling of the smooth muscle cells are discussed.
Unit Responses in the Rat Cochlear Nucleus to Tones of Rapidly Varying Frequency and Amplitude
Authors: Møller Aage R.
Published: December 2008

Møller, A. R. Unit responses in the rat cochlear nucleus to tones of rapidly varying frequency and amplitude. Acta physiol. scand. 1971. 81. 540–556.

The response of single units in the cochlear nucleus of the rat to sweep tones (FM sounds) and short tone‐bunts (AM sounds) has been investigated. It was found that the response pattern to Fhl sounds became more restricted with regard to tone frequency at a certain rate of tone‐frequency change. The probability of firing within a narrow frequency range surrounding the unit's CF became frequently more than ten times greater than that at low sweep‐speeds.

For a certain range of higher sweep‐rate, cycle histograms become narrower and higher than at low sweep‐rates. The range of frequency change where the peaks had maximal height was found to lie in the region between 1 and 15 MHz/sec for units with CF from 5 to 30 kHz. This effect was found to persist over a sound‐intensity range of more than 60 dB, but was less marked at very low intensity levels. The threshold of the units investigated did not become lowered at any rate of frequency change.

The cycle histograms of the response to sounds of constant frequency and variable duration (AM sounds) differed significantly from that to FM sounds. Only occasionally was an increase in height of the cycle histograms seen when the duration of the sounds was narrowed and the repetition rate increased.
Intracellular Accumulation and Permeability Effects of Some Weak Acids in the Isolated Frog Gastric Mucosa
Authors: Flemström Gunnatr
Published: December 2008

Acetate, propionate and L‐lactate (10 meq/l) stimulated hydrogen ion secretion in the isolated frog (Rana temporaria) gastric mucosa. By use of this stimulatory effect it was shown that these acids accumulate in the gastric mucosal cells when present in the undissociated form on the mucosal (secretory) side. From determinations of the impedance locus diagram and the resistance of the mucosa it was shown that undissociated propionic acid (100 meq/l) increased the ionic permeability of the frog gastric mucosa. A similar effect was obtained with acetic acid. It is probable that intracellular accumulation of undissociated weak acids is the mechanism underlying their permeability increasing effects on the gastric mucosa.
Effect of Some Drugs on the Uptake of Monoamines and Their Precursors in the Mouse Paneth Cells
Authors: Ahonen A. , Penttilä A.
Published: December 2008

The accumulation of some biogenic substances in the Paneth cell cytoplasmic granules of the mouse jejunum, ileum and colon and the effect of some drugs on this accumulation were studied, using the histochemical formaldehyde‐induced fluorescence method. The biogenic substances were injected i.v. and the specific catecholamine fluorescence appeared in the cytoplasmic secretory granules of the mouse Paneth cells about 10 min after I‐DOPA, dopamine, a‐methyl‐DOPA, noradrenaline, a‐methylnoradrenaline and adrenaline administration. Nia‐lamide and pargyline markedly intensified the fluorescence intensity in the Paneth cell granules after administration of the biogenic substance.

Imipramine and cocaine inhibited specifically the I‐DOPA and dopamine accumulation, whereas amphetamine, amitriptyline, nortriptyline, chlorpromazin, promazine and guanethidine had no effect. After nialamide pretreatment amphetamine, nortriptyline and amitriptyline were also capable of inhibiting slightly the accumulation of these biogenic substances. 5‐Hydroxytryptamine or 5‐hydroxytryptophan were not taken up by the Peneth cell granules even after nialamide pretreatment. The apparent mechanism of the accumulation of biogenic substances by the Paneth cell secretory granules was discussed.
Action Potential Generation in Denervated Rat Skeletal Muscle
Authors: Redfern Paul , Thesleff Stephen
Published: December 2008

Action potential generation was studied in the presence of tetrodotoxin (TTX) up to one week after denervation in individual muscle fibres of the extensor digitorurn longus and diaphragm muscles of the rat. TTX 10‐6M completely blocked spike generation in innervated inuscle and in niuscle denervated for one day. On the second and subsequent days after denervation, action potentials resistant to TTX were recorded in the muscle fibres. In the extensor digitorum longus muscle denervated for 5 days, action potentials recorded in the presence of TTX 10‐6M had a mean rate of rise 250 V/sec, and they exceeded the zero membrane potential by an average of 28 mV. This TTX resistant action potential generation was impaired by reducing the external sodium concentration, and abolished in the absence of that cation. A correlation was obsrrved between the presence of TTX resistant action potentials and the acetylcholine sensitivity of the muscle membrane.
Thermoregulation during Work in Carbon Monoxide Poisoning
Authors: Nielsen Bodil
Published: December 2008

A mild to moderate CO poisoning, blocking 25 to 33 % of the oxygen binding capacity of the blood, was used to produce a change in maximal oxygen intake (max VO2). Subjects working at the same work load (Vo2= 1.5 1/min) for 1 hour under normal conditions and during CO poisoning showed an increase in plateau level of deep body temperature (Te8) of 0.3–0.5° C. The plateau levels correlated with the relative loads (percentage of max Vo2) of the subjects but not with absolute work load and oxygen uptake. The CO‐poisoning may act 1) directly on the hypothalamic temperature center, the low tissue O2 tensions changing the activity of its neurons, 2) through the low venous O2 tensions on peripheral chemoreceptors in the working muscles or the venous side of the circulation, or 3) the changes in temperature may be a passive reaction to a shift in blood towards the periphery in the CO poisoned state.
The Effect of Deuterium on the Release and Uptake of Noradrenaline in Isolated Nerve Granules
Authors: Euler U. S. von , Lishajko F.
Published: December 2008

The release of noradrenaline (NA) from isolated bovine splenic granules in phosphate buffer is decreased by 10–25 per cent by addition of 50–90 % D2O to the medium. The ac companying uptake of 14C(‐)NA is unchanged in 50–70 % D2O and slgihtly decreased in 95 % D2O. After previous partial NA depletion of the granules the net uptake of NA in the presence of ATP‐Mg2+ is lowered by D2O in concentrations above 25 % in the medium and has fallen to 63 per cent of normal with 87.5 % D2O.
The Effect of Changes in the Blood Flow to the Tongue on the Chorda Tympani Response in Rat
Authors: Hellekant Göran
Published: December 2008

The summated chorda tympani response to taste stimuli was recorded in rats during repeated occlusion of the blood flow to the tongue. It was then observed that the response diminished and disappeared within a few minutes after bilateral or ipsilateral occlusion of the blood supply. Intravital staining through the lingual artery showed that each half of the tongue was chiefly supplied with blood from its ipsilateral lingual artery. A close relation between the simultaneous variation of the systemic blood pressure and the taste response was also observed and is discussed here.

This study was supported by grants from Swedish Medical Research Council grant No B71–14X‐2467.04 and Svenska Maltdrycksforskningsinstitutet.
Studies on the Intestinal Vasodilatation Observed after Mechanical Stimulation of the Mucosa of the Gut
Authors: Lungren Björn Biber Ove , Svanvik Joar
Published: December 2008

Mechanical stimulation of the jejune mucosa of the cat induces a transient increase of total intestinal blood flow amounting to 30–140 per cent of control. The vasodilatation is at least partly localized to the intestinal villi. The observed blood flow augmentation cannot be abolished by autonomic denervation or blockade by atropine, α‐ or β‐blocking agents or by a cholinergic ganglionic blocking agent. However, the intestinal blood flow augmentation was completely abolished by tetrodotoxin, a nerve conductivity blocking agent, by lidocaine, a local anesthetic, and by 2‐bromo‐LSD, a 5‐hydroxytryptamine (5‐HT) receptor blocker. These results seem to suggest that the studied intestinal vasodilatation is evokedviaan intramural nervous reflex in some way dependent on the release of 5‐HT.‐The observation that bile administered into the intestinal lumen causes a prolonged intestinal vasodilatation is briefly discussed.
Dopa‐decarboxylase in Autonomic and Sensory Ganglia of the Cat
Authors: Giacobini Ezio , Noré Barbro
Published: December 2008

As far as dopadecarboxylase (DDC) activity is concerned sympathetic ganglia can be collected into 3 groups: celiac and superior mesenteric show the highest activity, superior cervical and stellate are intermediate, lumbar and sacral ganglia show the lowest activity. Ciliary and nodose ganglia show significantly lower DDC activity than sympathetic ganglia and spinal ganglia show no measurable activity. There is a good correlation between DDC activities, monoamineoxidase (MAO) activities and the catecholamine contents of autonomic ganglia. Preganglionic de‐nervation did not significantly change DDC, MAO or catechol‐O‐methyltransferase (COMT) activity of L.r ganglia. It is concluded that although MIAO and DDC are not exclusively as sociated with adrenergic neurons, a high level of DDC or MAO activity in the cell body is a specific attribute of adrenergic neurons.
Dynamics of Arterial Oxygen Tension in Response to Sinusoidal Work Load in Man
Authors: Bjurstdt Hilding , Wigertz Ove
Published: December 2008

Dynamic characteristics of the response of arterial O2 tension (Pao2) to supine submaximal leg exercise were studied in 7 physically active young men. Pao2 was recorded continuously in the radial artery at the wrist; work load was varied sinusoidally between the extremes of 250 and 1050 kpm/rnin with periods of 0.75, 1.5, 3.0, and 7.0 min. Time‐averaging harmonic analysis showed a clear dominance of the fundamental component over the second and third harmonics in the Pao2 response, indicating approximately linear properties of the underlying system within the work‐load region studied. The transfer function for PaO2, exhibiting the characteristics of a variable regulated within narrow limits in the steady‐state condition, indicated that the basic response of PaO2 to a change in work load is a transient change in the opposite direction preceded by a pure time delay. Resonance occurred for work‐load periods near 3.0 min (peak‐to‐peak deviations approaching 14 mm Hg). Referring Pao2 changes to blood entering the left heart, the estimated time delay before a change in work load resulted in a change in Pao2 amounted to 15 sec. The existence of a resonance is interpreted in terms of an unbalance between factors determining O2 uptake from, and supply to, the alveolar space.
Dynamics of Arterial Blood Pressure Responses to Sinusoidal Work Load in Man
Authors: Rosenhamer Gunnar , Wigertz Ove
Published: December 2008

Systolic, diastolic, mean and pulse pressures in the radial artery, and heart rate in 7 physically active young men were subjected to frequency analysis by using sinusoidal work load as a forcing function. Subjects exercised in the supine position on a cycle ergometer. With the pedalling rate constant, the work load was varied sinusoidally over a range of drive frequencies between the two fixed extremes of 250 and 1050 kpm/min. Predicted step responses obtained by applying the trans fer functions estimated for radial systolic and pulse pressures showed close similarity to observed step responses, indicating linear properties of the underlying systems. Using known characteristics of the peripheral distortion of the pressure pulse, the responses of both the radial and central systolic and pulse pressures to work load could be described by second‐order transfer functions. Resonance occurred for periods near 7 min, indicating overshoots for both variables in the time domain. This behaviour suggests baroreflex inhibition as an explanation of an overdamped response of the heart rate. The changes in radial diastolic pressure were small and not clearly related to the drive frequency. The response of the radial mean pressure could not be described accurately by either first‐or second‐order functions, but exhibited phase lead features, suggesting sensitivity to rate of change in work load.
Synaptic Connections of the Paracervical (Frankenhauser) Ganglion of the Rat Uterus Examined with the Electron Microscope after Division of the Sympathetic and Sacral Parasympathetic Nerves
Authors: Mustonen T. , Teäväinen H.
Published: December 2008

The fine structure of the synapses in the paracervical (Frankenhauser) ganglion of the rat uterus was studied after sympathectomy and sacral parasympathectomy. Degenerative nerve endings to the ganglion cells were observed after division of both the sympathetic and parasympathetic nerves. No degeneration of the synapses to the chromaffin cells were seen. The results are interpreted as evidence of both sympathetic and parasympathetic innervation of the ganglion cells, which send their axons to the uterus, whereas the “chromaffin cells” are innervated by intraganglionic nerves.
Cyclic Variation of Body Temperature in Female Rabbits before and after Ovariectomy
Authors: Kihlström J. E. , Lundberg C.
Published: December 2008

The body temperature of 18 female rabbits was recorded once a day for about 3 months. Three of these rabbits demonstrated a statistically significant cyclic variation in temperature, the mean length of the cycles varying from 6 to 11 days.

The observed cyclic variations persisted after ovariectomy with cyclicity appearing in two additional animals. In 6 out of 8 rabbits the mean body temperature decreased significantly upon removal of the ovaries.
Long‐Term Changes in the ERG Following Transection of the Optic Nerve in the Rabbit
Authors: Borg Erik , Knave Bengt
Published: December 2008

The changes in ERG were studied in the: rabbit for 22 months after transection of the optic nerve. Immediately after the transection a small amplitude increase was found. This increase was constant for the next 8 months. Twenty‐two months after the section, however, the amplitudes decreased. The initial increase is interpreted as a functional sign of the existence of Centrifugal activity in the optic nerve that decreases retinal excitability. The final decrease in the ERG amplitudes is interpreted as a sign of retrograde degeneration in the retina.
Endotoxin‐induced Suppression of Rabbit Kidney DOPA Decarboxylase Activity
Authors: Fritz Hans , Håkanson Rolf
Published: December 2008

The kinetic properties of the histamine‐forming enzyme in the cortex of the rabbit kidney were found to be identical with those of DOPA decarboxylase. There was no evidence of “specific” histidine decarboxylase in the rabbit kidney cortex. Following i.v. injection of endotoxin, reduced DOPA decarboxylase activities were demonstrated after 3 and 6 hrs; after 24 hrs low as well as conspicuously high enzyme activities were observed.
Catecholamines, Monoamine Oxidase and Cholinesterase Activity in the Human Sympathetic Ganglion
Authors: Härkönen Matti , Penttilä Antti
Published: December 2008

Cholinesterase (ChE) and monoaniine oxidase (MAO) activities were measured in 17 surgically removed human lumbar sympathetic ganglia. Four further ganglia were obtained from accidentally killed men, autopsied at the Department of Forensic Medicine. ChEs were determined by automatic titration using acetylcholine, propionylcholine and butyrylcholine as substrates and specific ChE inhibitors (iso‐OMPA and 284C51). Of the total ChE activity (61.4 × 10‐‐3μmol/mg protein/min) 85%was found to be due to acetylcholinesterase (AChE, 53.6 × 10‐‐3μmol/mg protein/min) when acetylcholine was used as substrate. Propionylcholine (38.1 × 10‐‐3μmol/mg protein/min) was also mainly hydrolyzed by AChE (75%) and butyrylcholine (14.5 × 10‐‐3μmol/mg protein/min) by non‐specific cholinesterase (ns. ChE, 71 %). Histochemically, all the nerve cells showed AChE activity, most of them being moderately positive. Ns. ChE was chiefly present in the satellite cells and only a few weakly reactive nerve cells could be seen. MAO activity was measured fluorometrically with kynur‐amine as substrate (0.57 × 10‐‐3μmol/mg protein/min). Histochemically, all the nerve cells showed strong activity. Catecholamine fluorescence was weak in most of the ganglion cells. There were no significant differences in ChE or MAO activity between the different disease groups.
The Effects of K+ ‐free Solution on Tension Development in the Smooth Muscle Taenia Coli from the Guinea Pig
Authors: Axelosson Jóhann , Holmberg Bo
Published: December 2008

In the smooth muscle taenia coli from guinea pig changes in the pattern of electrical and mechanical activity and their relationship occur in K+‐free solutions. The ability to develop tension falls parallel with changes in intracellular concentrations of K' and Na'. The changes in mechanical properties are probably not according to interference with metabolic energy supply or more direct effects on the contractile components or passive mechanial properties. An interference with the normal functions of Ca2+ in the excitation‐contraction coupling is suggested.
The Effects of Changes in the Ionic Environment on Venous Smooth Muscle Distribution of Sodium and Potassium
Authors: Wahlström Bo
Published: December 2008

The sodium, potassium, calcium and magnesium content in the portal vein of the rat was determined by atomic absorption spectrophotometry in different environmental conditions. It was found that minute changes in the ionic environment caused considerable variations in the Na+, K+ and Ca2+ content, and Na/K ratio. Phosphate in the solution increased the sodium and calcium content. In sodiumfree solution all muscle sodium was rapidly lost. No bound sodium was detected. The ionic content of portal vein was also dependent on dissection and blotting technique. A standard procedure and a standard solution was therefore chosen. In this solution the following values were obtained: Na+: 88, K+: 52, Ca2+: 5.7 and Mg2+: 3.7 mmolelkg freshweight respectively.

The extracellular space, determined with 14C‐sorbitol was 490 ml/kg freshweight. The calculated intracellular concentrations and equilibrium potentials for Na+ and K+ were 62 and 157 mM and +21 and ‐86 mV respectively. The uptake of 42K showed that about 20 % of the total muscle potassium did not exchange within 5 hrs. The efflux of 42K+ showed that for the linear exchange of muscle potassium the rate constant was 0.85–0.90/hr.

K‐low solution decreased the efflux of 42K+ in spite of increased electrical activity. This suggests that the permeabilty to potassium is lowered. Noradrenaline had no effect on the 42K efflux in normal solution.
Aspects of the Cardiovascular Nervous Control in a Mammalian Diver (Myocastor Coypus)
Authors: Folkow B. , Lisander B. , ÖBerg B.
Published: December 2008

Experiments were performed to analyse to what extent diving mammals, represented by the coypu (nutria), exhibit similar characteristics with regard to cardiovascular nervous control as earlier found in diving birds such as the duck. As in this latter species, submersion of the un‐anesthetized coypu led to a profound and prompt bradycardia and reduction of cardiac output at a largely unchanged arterial pressure. ‐ Graded stimulations of the vasoconstrictor fibres to skeletal muscle, kidney and intestine in anesthetized animals produced far stronger responses at given stimulation rates than in non‐diving mammals (cats), and virtual flow obstruction could be achieved by rates as low as 6 imp/sec. The coypu thus possesses a vascular neuro effect or system, so organized as to shut off almost completely the blood supply to the mentioned tissues during a dive and hence distribute available oxygen reserves by means of a greatly reduced cardiac output preferentially to the brain and myocardium. Further, the vagal nerves exert on the heart ventricles a negative inotropic effect besides the profound negative chronotropic effect, helping to keep cardiac output very low during submersion. ‐ The cardiovascular nervous control in the coypu is therefore in important respects more related to that in diving birds than to that in non‐diving mammals, which probably is a prerequisite for the endurance of prolonged submersion.
Red Blood Cell and Plasma Volumes, Total Body Water and Sulfate Space in Obese‐Hyperglycemic Mice and Lean Litter Mates
Authors: Bill Anders , Herbai Georg , Westman‐Naeser Sighild
Published: December 2008

A comparative study was performed on different body compartments of mice with the hereditary obese‐hyperglycemic syndrome and their lean litter mates. In 5–months‐old obese mice the body weight was increased by 79 %, the red cell volume by 70 % and the plasma volume by 50 % as compared to lean controls. The blood volume per unit b. w. was probably lower and the orbital vein and body hematocrits were probably higher in the obese animals than in the non‐obese litter mates. The sulfate space of adult obese mice exceeded that of the controls by 27 %. The total amount of water in obese mice was not significantly different from that in lean mice. The erythrocyte: plasma sulfate ratio was approximately 0.3.
Efflux of Slow Reacting Substance (SRS) and Prostaglandins from Cat Paws Perfused with d‐Tubocurarine and n‐Octylamine
Authors: Strandberg Kjell
Published: December 2008

Release of histamine and formation of lipid‐soluble smooth muscle stimulating principles oc curred when cat paws were perfused with d‐tubocurarine or n‐octylamine. Regardless of re‐leaser the lipid‐soluble spasmogenic material was found to consist of two components, one of which chromatographically behaved as prostaglandin E2. Incubation of this principle with 15–hydroxy prostaglandin dehydrogenase in the presence of NAD' resulted in complete loss of the biological activity. The more polar component elicited slow, sustained contractions of the guinea‐pig ileum; effects associated with SRS. The chromatographic behaviour and chemical properties of this principle were the same as those of compound 48/80 induced SRS. The dose‐response relations and the time courses for the appearance of histamine and SRS induced by d‐tubocurarine and n‐octylamine were studied. The release processes were inhibited by N‐ethylmaleimide, potassium cyanide, dinitrophenol and disodium ethylene diamine tetraacetate (EDTA). The results indicate that in the cat paw d‐tubocurarine and n‐octylamine release histamine and induce the formation of identical or very similar lipid‐soluble spasmogenic principles by activating a common Ca++‐dependent energy‐requiring mechanism.
Alterations in Intracranial Pressure, Blood‐Brain Barrier, and Brain Edema after Sub‐chronic Implantation of a Cannula into the Brain of Conscious Animals
Authors: Edvinsson L. , Nielsen K. C. , Owman Ch. , West K. A.
Published: December 2008

Changes related to the intracranial pressure measured as the ventricular fluid pressure (VFP) accompanying implantation of a small cannula into the brain was studied in conscious rabbits. The cannula (7 mm‐long and 1.3 mm in diameter) was inserted into the left lateral ventricle, the intracerebral part of the cannula occupying 0.0093 cm3 volume. The ventricular fluid pres sure was continuously recorded on a Grass Polygraph via a cannula and a pressure transducer. Already within 1 hr after insertion of the cannula, VFP started to increase, and within 4–6 hrs it had reached a maximum about 5 times higher than the initial pressure. A slow progressive decrease did not supervene until 30–35 hrs after implantation; at 50 hrs the VFP was only twice the original value. This VFP was maintained during the following 25 hrs after which recording was discontinued. With trypan blue infusion, only an initial, transient, and local damage to the blood‐brain barrier could be demonstrated. Microscopy of stained sections revealed a varying degree of brain edema, anoxic cell damage, and damage to the capillary net work in the region of the track. The variation in extent of these changes corresponded well to the alterations in VFP and hence they see in to be an important reason for these alterations. The findings are discussed in terms of the important error introduced by these pressure alterations when recording various functional parameters from electrodes, needles, cannulas and other small instruments implanted into the brain parenchyma.
Quantitative Evaluation of Release and Reuptake of Adrenergic Transmitter in the Rabbit Heart
Authors: Wennmalm ÅKe
Published: December 2008

Drugs known to block the reuptake of noradrenaline into sympathetic nerves were compared with respect to their potency to increase the outflow of noradrenaline from the isolated rabbit heart in response to nerve stimulation. At a dose level where the drugs tested strongly and equally blocked the uptake of exogenous noradrenaline, they appeared to form two distinct groups differing in potentiation of the noradrenaline outflow. Thus, at optimal concentrations cocaine and desipramine were about equally efficient and increased the outflow of nor adrenaline by about 100%, while protriptyline, phenoxybenzamine and LU 3–010 raised the outflow by about 200 %. The effect of cocaine and desipramine on nerve stimulation‐induced outflow of noradrenaline was further increased by addition of the a‐blocking drug Hydergin. It is concluded that while all the drugs used increase the outflow of noradrenaline in response to nerve stirnulation by strongly depressing reuptake of the transmitter into the neurons, PBA, protriptyline and LU 3–010 apparently in addition augment the amount of noradrenaline re leased from the nerves, possibly by counteracting some braking mechanism normally restricting the release of noradrenaline in response to nerve stimulation.
The Effect of Protriptyline on the Disappearance and Nerve Impulse Induced Release of Labelled Metaraminol in the Rat
Authors: Almgren Olle
Published: December 2008

The uptake and disappearance of3H‐metaraminol (3H‐MA) after an i. v. injection of 40mUg / kgwas studied in intact hearts and in intact, atrophied (by duct ligation), decentralized and atrophied plus decentralized salivary glands of rats. The uptake of3H‐MA in the atrophied glands was reduced to 35 per cent of normal when calculated per gland. The disappearance rate of the amine from these glands did not differ from normal glands. Ten mg/kg of pro triptyline (PTP) 30 min after the3H‐MA injection greatly accelerated the disappearance of the amine from all types of glands also from the heart. The effect was weakest in the intact glands and most pronounced in the glands both atrophied and decentralized. The data argue in favor of a rapid leakage of MA through the neuronal cell membrane, normally balanced by the membrane pump, but unmasked if this pump is blocked. Extraneuronal binding appeals to influence the results obtained after PTP treatment.
Transducer Characteristics of the Muscle Spindle as Revealed by its Receptor Potential
Authors: Ottoson D. , Shepherd G. M.
Published: December 2008

The transducer properties of the sensory endings of the muscle spindle have been studied in isolated spindles of the frog's toe muscle. The depolarization of the sensory endings during dynamic stretch at constant velocity is a rectilinear function of the amount of lengthening of the spindle, for stretches up to about 30 % of its resting length. This suggests that the dynamic phase of the stimulus is transmitted to the endings with little distortion. When the spindle is stretched by more than 30 % of its resting length a saturation phase of constant depolarization is formed. The development of this phase may be explained by the assumption that parallel elastic elements take up the load or that the sensory membrane saturates beyond a given amount of distortion.

After release of stretch the depolarization of the endings decreases exponentially with time. The time course of repolarization is considerably slower than the return of the spindle to resting length and relatively independent of the rate of release of stretch. This suggests that the repolarization is governed by the transduction process and related to the electrical proper ties of the sensory membrane.
The Occurrence of ß‐Garotene in Blood Cells from Cattle
Authors: Nilsson Bo
Published: December 2008

Blood cells were prepared from cattle, sucking calves and pigs and the chief part of the hemoglobin was removed by hemolysis. The remains were disintegrated with ultrasonic vibration and extracted with phosphate buffer after which they were freeze‐dried and finally extracted with iso‐octane. Spectrophotometrical registrations of the iso‐octane extracts obtained from blood cells of adult cattle showed that the extracs contained β‐carotene. The concentration of β‐carotene in the disintegrated blood cells was estimated at about 0.5 mg%. In cattle β‐carotene thus occurs not only in the blood plasma, as stated in the literaure, but also in the blood cells. The iso‐octane extracts obtained from blood cells of sucking calves or pigs contained no measurable quantities of β‐carotene on account of which the β‐carotene in the blood cells from adult cattle seems to derive from the fodder.
Postnatal Excitability Changes of Kitten Motoneurones
Authors: Kellerth Jan‐Olof , Mellström Anders , Skoglund Sten
Published: December 2008

The responses of lumbosacral motoneurones to iterative dorsal root (DR) stimulation were studied in unanesthetized, spinalized kittens and adult cats by means of intracellular microelectrodes. The resting membrane potentials were found to increase in magnitude from birth up to 1.5 months of age. The action potentials increased in amplitude but decreased in duration with increasing age. In young kittens many cells, for several reasons considered to be motoneurones, failed to be invaded by antidromic spikes. In kittens less than 10 days old the majority of the action potentials did not show an overshoot. The amplitude of orthodromic spikes could be varied in kittens by varying the stimulation strength, probably due to summation of dendritic spikes. In young kittens supramaximal DR stimulation produced large depolarizations which generally decreased in magnitude with increasing age. Spikes elicited during such depolarization were often considerably reduced in amplitude (sometimes more than 50%). In young kittens almost all neurones responded with a monosynaptic spike to each DR‐stimulus at a frequency of 2/sec. This property gradually disappeared with increasing age, especially in extensor motoneurones. The findings are discussed in the light of some recent studies on the postnatal changes in morphology and physiology of the cat spinal cord.
ATP Hydrolysis and Noradrenaline Transport in Purified Vesicles from Splenic Nerve Trunk
Authors: Klein Richard L. , Lagercrantz Hugo
Published: December 2008

A fraction of highly purified noradrenaline (NA) storage vesicles isolated from bovine splenic nerve trunk was tested for ATP hydrolytic activity. At 37.5† C and pH 7.2, the specific activity of Mg++‐ and Ca++‐activated hydrolyses were 0.22 and 0.15 μM P1/mg protein/min, respectively. There was no hydrolysis in the absence of divalent cations. The additions of various combinations of Na+ and K+ salts had little effect. Concentrations of NA and dopamine between 0.1 and 10.0 μg/ml had no effect. A concentration of 5×10‐8 M reserpine, which produced 30–50% inhibition of NA exchangeability and influx rate, had no effect on ATP hydrolysis under a wide variety of conditions. This concentration of drug causes no obvious evidence of vesicle damage at the electron microscopic level. The data do not support the possibility of a link between ATP hydrolysis and NA transport in either direction across the membrane of the isolated nerve trunk vesicle.
Studies on the Site and Mechanism of Action of the Growth Inhibiting Effects of Estrogens
Authors: Herbai Georg
Published: December 2008

The effect of estrogens and growth hormone on the incorporation rate of sulfate into costal cartilage of the mouse was studiedin vivoandin vitroin normal, starving and hypophysectomized animals. Growth hormone was unable to counteract estrogen‐induced inhibition of sulfate incorporationin vivo.Starvation of the mice elicited a depression of sulfate uptakein vivo, but a simultaneous estrogen treatment caused a further decrease in sulfate incorporation in the starving mice. Sulfate incorporation into costal cartilage samplesin vitrowas markedly inhibited in the presence of estrogen in the incubation medium. Costal cartilage samples from hypophysectomized mice incorporated less35S‐sulfate than those from the controls, but estrogen in the medium caused no further decrease in sulfate uptake. Incorporation rates of3H‐acetate and35S‐sulfate were reduced to a similar degree by estrogen in the medium. It is concluded that estrogen‐induced inhibition of growth is neither due to growth hormone deficiency, nor to an appetite diminishing effect of the hormones. Estrogens exert a local inhibitory effect on sulfate (and acetate) incorporation in the chondrocytes and growth stimulation of the cells is a necessary condition for the appearance of the inhibiting actions of estrogens.
Renal Vascular Resistance in Spontaneously Hypertensive Rats
Authors: Folkow Björn , Hallbäck Margareta , Lundgren Yen , Weiss Lilian
Published: December 2008

The renal vascular beds of one spontaneously hypertensive rat (SHR) and one matched normotensive control rat (NCR) were perfused with oxygenated plasma substitute in 27 paired expts. Pressure‐flow curves indicated that the renal vascular resistance is lower in SHR than in NCR during maximal dilatation, in contrast to the situation in other major circuits, while the SHR renal resistance vessels are less distensible than those of NCR.–Graded noradrenaline (NA) infusions showed that the NA threshold does not differ significantly between the two groups, but SHR displays a steeper dose‐response curve and an increased maximal pressor response as compared to NCR.–The results suggest an increased media thickness in the SHR renal resistance vessels, raising their wall/lumen ratio, “reactivity” and maximal contractile strength but reducing their distensibility. However, while the thickened vascular walls in other major circuits encroach upon the lumina, even at maximal dilatation (Folkowet. al.1970 a, b), they are in the kidneys combined with increased vascular lumina. This implies a larger renal blood supply in SHR than in NCR at very low level of vascular tone while the reverse is true at enhanced tone, due to the steeper resistance curve in the SHR.
Effect of Angiotensin on Plasma‐Free Fatty Acids in Dogs
Authors: Akre Stein , Mjøs Ole Danbolt
Published: December 2008

Mechanisms underlying the plasma‐free fatty acids (FFA) lowering effect of angiotensin have been studied in anesthetized dogs. Angiotensin in pressor doses reduced fatty tissue blood flow (FBF) as well as plasma‐FFA. After ganglionic blockade, angiotensin had the opposite effects, as a slight increase was found in FBF and plasma‐FFA. Atropine or a β‐adrenergic blocking agent did not interfere with the angiotensin effect on plasma‐FFA. It is concluded that the angiotensin action on plasma FFA is secondary to its vasoconstrictive effect in adipose tissue.