bluuebunny/crossref_metadata_2025 huggingface dataset:
A Respiratory Reflex Elicited by Hemorrhage and Mediated by Vagal Afferents
Authors: Sjöstrand Torcny
Published: December 2008

Ventilation, heart rate and arterial pressure were recorded in rats on blood losses from 1 to 6 ml (6–36 % of blood volume). About 15 s after the onset of the blood drawing and the coincident decrease of arterial pressure, the tidal volume increased on a loss of 1–3 ml. This was regularly observed in 10 rats. On larger hemorrhages the tidal volume decreased. The respiratory rate decreased in some animals already at a blood loss of 1 ml, in others at losses above 2 ml. The increase of the tidal volume was totally inhibited in 5 rats by exclusion of afferents in the recurrent nerves by cold block or section. In three other rats the increase of the tidal volume was inhibited on cutting also of the right or both vagal nerves. The decrease of tidal volume and of respiratory frequency on large blood losses was not inhibited by vagotomy. It is presumed that the increase of the tidal volume on a small to moderate blood loss is provoked by a vagal reflex elicited by receptors on the low pressure side and that the decreased ventilation on larger hemorrhages is elicited from the respiratory centres by the change of the cerebral blood flow.
Intestinal Vascular Responses to 5‐Hydroxytryptamine
Authors: Biber Björn , Fara John , Lundgren Ove
Published: December 2008

The in vivo and in vitro effects or 5‐hydroxytryptamine (5‐HT) were investigated on the mesenteric vasculature of the cat. Close i.a. injections (10 μg) or infusions (10–15 μg/min) into the superior mesenteric artery of chloralose anesthetized cats generally induced an intestinal vasodilatation of 60–150 % above control which was unaltered by α‐or β‐adrenergic or cholinergic receptor blockade, and which after its development was unaffected by intestinal motility responses. Following nerve blockade by tetrodotoxin, the vasodilator response to 5‐HT was changed to vasoconstriction. During 5‐HT infusions of 20–50 μg/min intestinal blood flow and intestinal capillary filtration coefficient (CFG), measured plethysmographical‐ly, increased significantly above control, while at infusions of 10–15 μg/min 5‐HT increased CFC without increasing intestinal blood flow. In in vitro studies on strips or segments of mesenteric arteries and veins from the cat and rat, 5‐HT constantly increased isometric tension in all vessels studied. The response was unaltered by adrenergic or cholinergic receptor blockade and was not related to passive tension applied to the vessels nor to the presence or absence of noradrenaline in the bath. The divergent in vivo and in vitro response are discussed in terms of the following possible mechanisms: 1. A differential effect of 5‐HT with constriction of large vessels and dilatations of smaller ones; 2. A direct constrictor effect on the vascular smooth muscle via specific serotonic receptors, as well as an indirect dilator effect, perhaps mediated through local nervous pathways.
Metabolism of14C‐Histamine in Goats and Pigs Treated with Aminoguanidine
Authors: Eliassen Knut Arnet
Published: December 2008

The effect of aminoguanidine, an inhibitor of diamine oxidase (E.C. 1.4.3.6.) on the catabolism of14C‐histamine has been studied in goats, a species in which oxidative deamination dominates, and pigs, a species in which methylation is the most important route of inactivation. In aminoguanidine treated goats the total14C‐imidazoleacetic acid (14C‐ImAA) in urine was reduced from about 70% to about 4% and in pigs from 18% to 2%. In goats the decrease in the formation of14C‐ImAA was partly compensated by an increased methylation though the fraction of14C‐histamine excreted unchanged was increased tenfold in the last‐mentioned species. In pigs the decrease in14C‐ImAA seemed to be fully compensated by increased methylation of histamine. The decrease in the excretion of non‐radioactive 1.4‐MeImAA in pigs and the change in the ratio:14C‐1.4‐MeImAA/14C‐1.4‐MeHi in both pigs and goats during aminoguanidine treatment indicated that oxidation of 1.4‐MeHi to 1.4‐MeImAA is partly catalyzed by enzymes sensitive to aminoguanidine. The incomplete inhibition of the14C‐ImAA formation during aminoguanidine treatment indicates that enzymes other than diamine oxidase might participate in the oxidation of histamine to ImAA.
Lateral Line Input to the Crista Cerebellaris in the Eel. Field Potentials and Histology
Authors: Alnæs Egil
Published: December 2008

The central nervous effects of electrical stimulation of the Nn. lat. posteriores have been investigated. Maximal field potential amplitudes were found in the medial part of the ipsilateral crista cerebellaris. The field potential evoked from stimulation of fast conducting nerve fibres consisted of an afferent pre‐synaptic volley and a post‐synaptic complex wave. The latter is shown to consist of a population EPSP and a population spike in subcristal neurones. Excitatory activity from the contralateral nerve impinges on the same neurones, and bilateral summation occurs. The contralateral field potential reverses more superficially than does the ipsilateral field. Post‐excitatory reduction of population spike can be explained by refractoriness. The crista region was investigated with conventional light and electron microscopical methods. Myelinated primary afferent axons from the R. lat post. N. X. terminate in the subcristal region on the ipsilateral side. Subcristal cells have dendritic ramifications in the molecular layer. Unmyelinated axons in this layer partly consist of lateral line primary afferents. These axons differ from the cerebellar parallel fibres by their extensive branching and irregular directional architecture. Fusiform swellings of these axons establish abundant isomorphous synapses with dendritic spines. The distribution of field potential negativity in depth corresponds to the distribution of subcristal neurones.
The Effects of Vasoconstrictor Fibre Stimulation on Consecutive Vascular Sections of Cat Small Intestine during Hemorrhagic Hypotension
Authors: Haglund Ulf , Lundgren Ove
Published: December 2008

The effects of the regional sympathetic vasoconstrictor fibres on the consecutive vascular sections of the small intestine of the cat were studied during a 2–2.5 h hemorrhagic hypotension using a plethysmographic technique. The constrictor fibres were intermittently stimulated at 4 Hz before, during and after a hypotensive period at approximately 60 or 40 mm Hg. The nervous responsiveness of the resistance vessels and of the capacitance vessels declined continuously throughout the hypotensive period, the rate of decline being higher the lower perfusion pressure and the lower the arterial blood pH. The capillary filtration coefficient (CFC), reflecting the tonus of the “precapillary sphincters”, was increased during the hypotensive period. Nervous activation reduced CFC throughout the experiments. Tissue volume increased continuously during the latter half of most experiments at 40 mm Hg, probably reflecting a deranged Starling equilibrium across the capillary wall. During the post‐hypotensive control period after a 40 mm Hg hypotension arterial blood pressure fell rapidly. Mucosal ulcerations were regularly found in these animals and the pathogenesis of these lesions is tentatively discussed.
Further Evidence for the Importance of CSF Na+ Concentration in Central Control of Fluid Balance
Authors: Olsson Kerstin
Published: December 2008

Slow (0.05 ml/min) infusions of hypo‐, iso‐, and hypertonic solutions of d‐glucose, fructose and sucrose into the CSF of the lateral cerebral ventricle of the goat were found to repress the dipsogenic, antidiuretic and natriuretic responses to intracarotid infusions of hypertonic NaCl. Corresponding intraventricular infusions of slightly hypotonic (0.14 M) NaCl, and of 0.3 M d‐glucose in 0.14 M NaCl did not have this repressive effect. The results are taken as support for the idea that a central receptor system, which is sensitive to variations in the Na+ concentration of the CSF, plays an important role in the control of body fluid homeostasis.
Effect of Contractions in Vitroon Glycogen Content and Glycogen Synthetase Activity in Muscle
Authors: Adolfsson Sten
Published: December 2008

The influence of contraction on the content of glycogen in muscle as well as on the activity of the glycogen synthetase enzyme (EC 2.4. 1. 11.)—rate‐limiting for glycogen synthesis—has previously been investigated in vivo. In the present study this influence was studied in vitro, where interference of epinephrine and insulin on the the effects of contraction is more easily excluded. Electrically stimulated intact levator ani muscle preparations from prepubertal rats were used (Arvill, Acta endocr. 1967. 56. suppl. 122). Glycogen content decreased during 15 min of intermittent tetanization (10 slmin). There was no change in synthetase activity during the contractions. For the period following contractions an increase in the per cent active I‐form of the enzyme was found after 1, 2, 10 and 180 min. Resynthesis of glycogen was shown after 30–180 min. An inverse relation between % I‐form and glycogen content was found when data from 1–10 min after contractions were plotted together with the data from unstirnulated muscles. During repeated single twitches (1/s) for 60 min there was an enhanced penetration of xylose‐14C and a higher rate of incorporation of glucose‐14C into glycogen compared to control muscles. The present results are in good agreement with those previously obtained in vivo. Thus, the influence of contractions in vivo could be demonstrated also in vitro.
Antidromic Activation of Renshaw Cells and their Axonal Projections
Authors: Jankowska E. , Smith D. O.
Published: December 2008

Antidromic invasion of Renshaw cells following stimulation of their axons was found always to produce only a single spike in contrast to repetitive synaptic discharges. A systematic exploration of the spinal cord in a search for sites from which single Renshaw cells could be activated antidromically revealed that their axons: 1) can project to distances over 12 mm, 2) run in the ventral funiculus. 3) are likely to terminate both within motor nuclei (mainly at short distances) and in an area dorso‐medial and medial to them, and 4) have a maximal conduction velocity of about 30 mls.
The Effect of Insulin on Epinephrine and Glucagon Inactivated Glycogen Synthetase I in the Isolated Perfused Rat Liver
Authors: Hostmark Arne T.
Published: December 2008

The effect of insulin on the reactivation of the epinephrine or glucagon inactivated glycogen synthetase I in the isolated perfused rat liver has been investigated. Livers from fed rats and fasted rats were perfused with Krebs‐Ringer bicarbonate buffer, using either a recirculating or non‐recirculating apparatus. Inactivation of the glycogen synthetase I was observed following th administration of epinehprine or glucagon. It was demonstrated that insulin added 10–15 min after epinephrine or glucagon promoted the reactivation of synthetase I without altering the perfusate glucose concentration. Reactivation by insulin was also observed when livers were perfused with a glucosefree medium in a non‐recirculating system. It is concluded that this action of insulin is not dependent upon the presence of giucose.
A Comparative Study of in vitro Metabolism of Histamine in Various Tissues from Domestic Animals (Cow, Sheep, Horse and Pig)
Authors: Eliassen Knut Arnet
Published: December 2008

Previously, the in vivo metabolism of histamine in domestic animals has been examined. Ruminating and non‐ruminating species seemed to metabolize both parenterally and orally administered Hi in different ways. The present report is concerned with the ability of various tissues from the two types of animal to metabolize histamine. In all species kidney was the most active, and lung one of the least active histamine degrading tissues. In ruminating species, liver seemed to be the most active tissue next to kidney, while intestinal mucosa was of relatively minor importance. In the non‐ruminating species mucosa of the small intestine was the most active tissue after kidney, while liver was less active. Imidazoleacetic acid and an unidentified “metabolite XI” were the 2 main metabolites of histamine in most tissues examined, both at low and high substrate concentrations. The formation of “metabolite XI” was prevented by 10‐4 M aminoguanidine. Addition of S‐adenosylmethionine to the incubation mixtures in‐creased the inactivation rate of histamine in the lung of all species examined, in the intestinal mucosa of the ruminants and in the liver of the non‐ruminants. 1,4‐McH, did not seem to be oxidized to any extent in the methylating tissue.
Effects of Chlorpromazine, Imipramine, and Quinidine on Action Potential and Tension Development in Single Skeletal Muscle Fibres of the Frog
Authors: Anderson K.‐E.
Published: December 2008

The effects of chlorpromazine, imipramine, and quinidine on resting membrane potential, action potential, twitch and tetanic tensions, and on the active state were investigated in single frog skeletal muscle fibres. Chlorpromazine in concentrations 10‐6–10‐5M, and imipramine and quinidine in concentrations 10‐5–5 × 10‐5M, did not affect the resting membrane potential but produced a dose‐dependent decrease in the rate of rise, rate of fall, and overshoot of the action potential. The duration, measured at –50 mV, was prolonged. The drugs potentiated the isometric twitch by increasing the duration of the active state. Tetanic tension was not affected. In high concentrations (chlorpromazine 3 × 10‐5M, imipramine and quinidine > 5 × 10‐5M) the drugs caused a successive widening and decrease of amplitude of the action potential and finally blocked the electrical activity. After a marked initial increase, the peak twitch tension was reduced in parallel with the changes of the action potential. The reduction in twitch amplitude was probably due to incomplete activation of the fibres. The mechanisms of the effects on the excitation‐contraction coupling induced by chlorpromazine, imipramine, and quinidine are discussed.
Differential Effects of Ethyl Alcohol on Retinal Functions
Authors: Bernhard C. G. , Knave B. , Persson H. E.
Published: December 2008

The action of ethyl alcohol on retinal function was analyzed by comparing its effects on the conventional and low‐intensity ERG in the dark‐adapted intact sheep eye. The results showed an increase of the b‐wave and a decrease of the a‐wave amplitude after small doses of alcohol (b.a.c. 20–40 mg%). The low‐intensity ERG, i.e. the electroretinographic responses below b‐wave threshold has recently been shown to consist of a slow, corneanegative receptor response and two fast d.c. responses of opposite polarities from the inner nuclear layer. The negative d.c. response is considered inhibitory in nature and the positive d.c. response excitatory. Administration of alcohol had no effect on the isolated receptor response but elicited an amplitude increase of the positive d.c. response. The results from the low‐intensity ERG experiments suggest the mechanism behind the effects of alcohol on retinal functions to be a selective suppression of the negative d.c. response. Hereby the “controlling” function on the cells generating the positive d.c. response is suppressed, thus “releasing” the positive d.c. response and the b‐wave, which has been shown to be built up by the positive d.c. response. The decrease of the a‐wave appears to be secondary to the increase of the b‐wave, all the more as it was shown that alcohol had no effect on the receptor response. At high blood alcohol con‐centrations, the a‐wave as well as the b‐wave amplitude were found to diminish as an expression for a presumed, general depression of the c.n.s.
Appearance of Red Cells in Peripheral Lymph during Radiation‐Induced Thrombocytopenia
Authors: Aursnes I.
Published: December 2008

Some effects of marked thrombocytopenia have been studied in rabbits exposed to whole body irradiation with the ears shielded. In most animals marked thrombocytopenia was present 9–13 days after the irradiation. Lymph samples were obtained by draining a lymph vessel at the base of the ear. In 7 out of 11 rabbits a marked rise in the content of red cells in ear lymph occurred during thrombocytopenia. In the 4 other irradiated rabbits, which developed the same degree of thrombocytopenia, no such red cell increase in the ear lymph occurred. The reason for this is not known. Platelet production may have been resumed at an earlier stage in these 4 animals. The first few platelets produced at the end of the thrombocytopenic period were apparently consumed in repairing the endothelium. This notion is supported by the fact that in some of the 7 rabbits of the former group the erythrocyte‐containing lymph was normalized one day before the number of circulating platelets started to rise. All rabbits showed a steady fall in body weight after irradiation. In the 7 rabbits with red cell increase in lymph, however, a moderate whole body weight gain could be observed at the time with marked thrombocytopenia. This suggests the existence of a slight degree of oedema during thrombocytopenia in these animals.
Histochemical Demonstration of Carbonic Anhydrase Activity in the Human Kidney
Authors: Lönnerholm Gudmar
Published: December 2008

The distribution of carbonic anhydrase activity along the tubules of fresh human donor kidneys, prepared for transplantation, was studied by the histochemical method of Hansson. Enzyme activity was demonstrated in the cells of the convoluted part of the proximal tubule, including the brush border region. The straight part of the proximal tubule contained little or no enzyme, indicating a functional differentiation of the two parts of the proximal tubule. The staining of the thin limb was different in fixed and unfixed tissue. The straight and convoluted parts of the distal tubule, however, showed distinct enzyme activity. In the major part of the collecting duct a mosaic of cells was found; some cells with high and other cells with no or low enzyme activity. In the most distal part near the papilla, however, no enzyme activity was found. The present study shows that carbonic anhydrase is present in those parts of the kidney tubules where there is a postulated role for it. The distribution of the enzyme in the human kidney is similar to that seen in the rat and dog kidney, which suggests a common pattern of urinary acidification in these species.
Urinary Excretion of Noradrenaline in Response to Tilting in Aged
Authors: Hedfors Eva
Published: December 2008

Urinary excretion of noradrenaline was measured after 1 h in supine and 1 h tilted head‐up 70 in 8 healthy persons 71–75 years of age. The lack of increase in noradrenaline excretion in response to tilting found in the investigation is probably a normal consequence of an altered reflex circulatory adaptation in this age group.
Mucosal Hemodynamics in the Small Intestine of the Cat during Reduced Perfusion Pressure
Authors: Lundgren Ove , Svanvik Joar
Published: December 2008

This study was performed with an indicator‐dilution technique that allowed quantitative and separate investigation on the cat small intestine, of the “mucosal” as well as of the “villous” intravascular flows and volumes. When reducing arterial inflow pressure from about 100 to about 30 mm Hg “villous” plasma volume and mean transit time increased while “villous” plasma flow remained largely unaltered. Concomitantly, total intestinal blood flow decreased significantly indicating that a larger fraction of total plasma flow was diverted to the villi at low inflow pressure. When intestinal blood flow was reduced by increasing venous outflow pressure villous hemodynamics was largely unaffected. “Mucosal” red cell and plasma flows were affected in the direction of and, generally speaking, in proportion to total intestinal blood flow. These results suggest that the autoregulatory capacity of the villous vessels is larger than that of the vessels in the deeper parts of the mucosa.
Effects of Hernodilution Induced by Hyperoncotic Dextran 40 on Cardiac Contractility
Authors: Pavek Karel
Published: December 2008

In 5 pentobarbital‐anesthetized dogs with autonomous nervous activity blocked with atropine and propranolol, 1 g/kg of dextran 40 as 10% solution was rapidly infused into the right atrium. After dextran, the heart rate was not changed while the mean arterial pressure increased slightly by 5 mm Hg. Cardiac contractility was studied by a continuous display of left ventricular pressure velocity curves. Peak velocity of contractile elements, dP/dt/P estimated at comparable enddiastolic pressure, was not consistently changed after dextran. A higher stroke volume at comparable enddiastolic pressure after dextran suggests improved ventricular function. This might be caused by a decreased aortic impedance. No signs of depressed cardiac contractility occurred after a large dose of dextran 40.
Effects of Adrenaline, Noradrenaline and Isoprenaline on the Electrical and Mechanical Responses of the Guinea‐Pig Vas Deferens to Nerve Stimulation
Authors: Sjöstrand By Nils O.
Published: December 2008

Sjöstrand, N. O. Effects of adrenaline, noradrenaline and isoprenaline on the electrical and mechanical responses of the guinea‐pig vas deferens to nerve stimulation. Acta physiol. scand. 1973. 89. 10–18.

The effect of noradrenaline, adrenaline and isoprenaline on the electrical and mechanical responses of the guinea‐pig vas deferens to nerve stimulation was studied with the sucrose gap technique. A stimulatory α‐adrenergic effect was found. This was due to a depolarization of the smooth muscle cell membrane. An inhibitory β‐adrenergic effect was observed in some preparations. It consisted of a hyperpolariiSation of the membrane potential and a decrease in size of the excitatory junction potentials. Thirdly, in a few preparations an inhibition of the excitatory junction potentials was seen, which was not a β‐effect but could partly be antagonized by phentolamine. It is suggested that this effect is due to an n‐sympathicomimitic inhibition of the neurotransmission in the vas deferens.
Acid Production in the Isolated Perfused Rat Liver
Authors: Morland By Jorg , Christoffersen Thoralf , Osnes Jan‐Bjorn
Published: December 2008

Morland, J., T. Christoffersen AND J.‐B. Osnes. Acid production in the isolated perfused rat liver. Acta physiol. scand. 1973. 89. 61–67.

The release and production of organic acids were studied in isolated perfused rat livers. The livers were perfused at different pH with and without ethanol. Liver homogenate pH was measured in certain experiments. The results showed that the basal production of acid by the liver, was greatest in the early phase of perfusion, probably due to the low initial concentration of acid metabolites in the perfusate. The acid production declined when perfusate pH was reduced and increased when perfusate pH was raised. Ethanol treatment (perfusate concentration 30–45 mM) increased the liver acid production. Liver homogenate pH was more reduced after ethanol than after acid addition to the perfusate at the same perfusate pH. It is postulated that ethanol metabolism may influence pH‐sensitive metabolic reactions by the accompanying acid production.
Colonic Motility in the Cat
Authors: Rostad Hans
Published: December 2008

Rostad Colonic motility in the cat. 1. Extraluminal strain gage technique. Influence of anesthesia and temperature. Acta physiol. scand. 1973. 89. 79‐ 90.

A technique for recording colonic motility in vivo with extraluminal strain gage transducers is described. This technique allowed segmental recording of the motility and proved more sensitive than intraluminal pressure devices. The transducers did not appear to interfere with the spontaneous colonic activity. Immediately after laparotomy considerable activity was observed in all parts of the colon. The degree of spontaneous motility varied from animal to animal, and from time to time in the same animal. The colon was seldom quiet unless the anesthesia was deep. Two main types of spontaneous contraction waves were observed: (i) slow waves of 0.5‐2.0 min duration, and (ii) rhythmic waves of a frequency of 4–7 per min. Cooling of the abdominal wall resulted in augmented colonic motility, warming caused relaxation and reduced activity. Variation in body temperature between 3G and 39o did not influence the motility.
Driving Forces over the Peritubular Capillary Membrane in the Rat Kidney during Antidiuresis and Saline Expansion
Authors: Källskog Ö. , Wolgast M.
Published: December 2008

Källskog, Ö. and M. Wolgast. Driving forces over the peritubular capillary membrane in the rat kidney during antidiuresis and saline expansion. Acta physiol. scand. 1973. 89. 116–125.

The driving forces operative over the renal peritubular capillary membrane has been investigated on a series of male Sprague‐Dawley rats. The hydrostatic capillary pressure was measured by micropuncture technique using a servo‐controlled counter pressure device according to Wiederhielm. The oncotic pressure was estimated from the protein concentration, calculated as the arithmetic mean of the concentration in the proximal end (=plasma concentration/1‐filtration fraction) and that in the distal end of the capillary (= plasma concentration). For estimation of the corresponding interstitial variables a small (50 μm) PCV catheter‐was put into the subcapsular space. The hydrostatic pressure was measured with the same system as for capillaries and the oncotic pressure from the protein concentration in samples withdrawn via the microcatheter. Under control antidiuretic conditions the capillary hydrostatic pressure averaged 11.1 mm Hg and the oncotic 27.7 mm Hg. In the interstitium the corresponding pressures amounted 1.3 mm Hg and 4.0 mm Hg, respectively. In saline expansion the interstitial hydrostatic pressure almost doubled whereas the oncotic pressure decreased towards zero, partly compensating the decrease in net driving force caused by the decreased plasma oncotic pressure following the expansion. Data from lymph flows suggest that the capillary membrane has a small and a large pore system and from these suggestions a model for the regulation nf renal interstitium is presented.
Muscle Spindles in a Flexion Reflex Elicited by Natural Stimulation
Authors: Appelberg Bo
Published: December 2008

Appelberg, B. Muscle spin flexions in a flexion reflex elicited by natural stimulation. Acta physiol. scand. 1973. 89. 145–153.

In the decerebrate and unanesthetized cat, spinalized at low thoracic level a flexion reflex in the peroneus tertius or the semitendinosus muscle was evoked by natural stimulation of the paw. The behaviour of primary muscle spindle afferents from the muscle under phasic as well as static conditions was studied in the absence of as well as during a reflex contraction. On the basis of the reactions of the spindles to these tests it could be concluded that during a flexion reflex evoked in a natural way static fusimotor neurones are active together with alpha motoneurones. Dynamic fusimotor neurones, on the other hand, do not participate in the reflex.
Colonic Motility in the Cat
Authors: Rostad Hans
Published: December 2008

Rostad, H. Colonic motility in the cat. V. Influence of telencephalic stimulation and the peripheral pathways mediating the effects. Acta physiol. scand. 1973. 89. 169–181.

The cerebral cortex and intracerebral structures were stimulated in lightly anesthetized cats while colonic motility was recorded using extraluminal strain gage transducers. Excitatory colonic responses were produced from the anterior ectosylvian gyrus (the second somatic sensory‐motor area) and from a small zone around the anterior end of the lateral sulcus. These effects were shown to be mediated through the vagal nerves. Colonic inhibition resulted from stimulation of three separate cortical zones, the anterior sigmoid, the orbital and the anterior cingulate gyrl These effects were mediated mainly through the lumbar colonic nerves. Stimulation of the amygdaloid nuclei produced excitatory colonic effects mediated through the lumbar colonic nerves. Inhibitory effects were not obtained from the amygdala. Finally, weak colonic contractions resulted from stimulation of the olfactory bulb and tract and were found to be conveyed through the parasympathetic vagal and pelvic nerves.
Electrical Stimulation of Human Thalamic and Amygdaloid Area and Plasma Cortisol Concentration
Authors: Leppäluoto Juhani
Published: December 2008

Leppaluoto, J. Electrical stimulation of human thalamic and amygdaloid ana and plasma Cortisol concentration. Acta physiol. scand. 1973. 89. 187–191.

The concentration of plasma Cortisol was measured from blood samples drawn through indwelled catheters at 3–5 min intervals in 4 resting healthy subjects and in 5 patients after electrical stimulation of the thalamus and amygdala via chronic electrodes implanted for the treatment of psychomotor seizures. In the healthy subjects (laboratory staft) the plasma Cortisol level, measured by a fluorometric method, was initially high (10 ‐ 37 μg/100 ml), evidently due to emotional affectivity of the experimental situation, and decreased within 10 min by 10μg in 2 subjects and the increased within 10 min by 5–20 μg in 3 subjects. These rapid changes of the plasma Cortisol level, bursts, were significant and are a new physiological phenomenon. In the patients the thalamus and amygdala were stimulated 30 s (pulse duration 1 ms, repetetive frequency 50 Hz, unidirectional square wave pulses) to the voltage level at which the patient felt a subjective sensation (4 ‐12 V). After repetctive stimulations of thalamus (3 patients, 6 times) and amygdala (2 patients, 3 times) the changes in the plasma Cortisol levels were inconsistent and similar to those seen in the healthy subjects. No conclusion about the function of the pituitary‐adrenal axis and amygdala of thalamus was drawn, because the plasma Cortisol values were evidently influenced by their temporal relation to the secretion bursts presented here.
Secretory Fibres in the Trigeminal Part of the Lingual Nerve to the Mandibular Salivary Gland of the Rat
Authors: Hellekant Goran , Kasahara Yasuo
Published: December 2008

Hellekant, G. and Y. Kasahara. Secretory fibres in the trigeminal pa'.rt of the lingual nerve to the mandibular salivary gland of the rat. Acta physiol. scand. 1973. 89. 198–207.

The nerve supply to and the secretion from the mandibular salivary gland of the rat have been studied. It was found that a) secretory fibres are given off from the chorda‐lingual nerve on its peripheral course until it reaches the mandibular and sublingual ducts, b) secretion of saliva was observed and secretion could be evoked even when the facial portion of the chorda‐lingual nerves was cut. The flow did not stop until its trigeminal portion was also cut, c) the cessation of secretion after the trigeminal portion was cut was not the result of a loss of sensory impulses to the CNS, d) impulses could also be recorded fiorn the nerve fibres given off from the chorda‐lingual nerve to the gland after its facial portion was cut; e) electrical stimulation of the peripheral part of the trigeminal portion elicited secretion, which was generally larger than that in response to stimulation of the facial portion. Simultaneous stimulation of both portions gave the largest secretion, f) no difference between the sodium and potassium concentrations in saliva elicited by stimulation of the two nerve portions was observed. Atropine blocked the secretion caused by stimulation of any of the nerves.
The Influence of Blood Flow on the Rate of Absorption of 85Kr from the Small Intestine of the Cat
Authors: Biber Björn , Lundgren Ove , Svanvik Joar
Published: December 2008

Biber, B., O. Lundgrenand J. Svanvik. The influence of blood flow on the rate of absorption of 85Kr from the small intestine of the cat. Acta physiol. scand. 1973. 89. 227–238.

A method for studying the absorption rate of an easily diffusable substance, sr‘Kr, from the small intestinal lumen to the intestinal blood stream is described and tested. The technique involves a fast, luminal perfusion with saline having a constant concentration of s’Kr and a continuous registration of the radioactivity in the venous outflow from the intestine. Absorption rate is estimated from the amount of tracer appearing in the mesenteric vein and expressed as volume of blood that per unit time is fully equilibrated with the luminal contents. During “resting” conditions (total intestinal blood flow 25 ml/minX100 g) the absorption rate was about 5 ml/minx 100 g and during a moderate hyperemia (total intestinal blood flow 100 ml/ minX100g) induced by isopropylnoradrenaline absorption rate increased to about 13 ml/minX100g. The results are discussed in relation to the small intestinal mucosal blood circulation and countercurrent exchanger.
Effects of Acetylcholine and Papaverine on the Secretion and Blood Flow from the Pancreas of the Cat
Authors: Lenninger Sven
Published: December 2008

Lenninger, S. Effects of acetylcholine and papaverine on the secretion and blood flow from the pancreas of the cat. Acta physiol. scand. 1973. 89. 260–268.

Acetylcholine and papaverine were injected into the coeliac artery of cats in which the pancreatic secretion and blood flow were recorded. Acetylcholine evoked a small secretion from the resting gland but papaverine did not. During secretion induced by secretin both acetylcholine and papaverine caused an increase in the rate of secretion and both drugs also increased the rate of blood flow. The relationship between the changes in secretion and blood flow is discussed.
The Effect of Hemorrhage on Hepatosplanchnic Hemodynamics, Liver Function and Hepatic Metabolism
Authors: Krarup Niels
Published: December 2008

Krarup, N. The effect of hemorrhage on hepatosplanchnic hemodynamics, liver function and hepatic metabolism. Acta physiol. scand. 1973. 89. 269–277.

Cats in the postabsoiptive state and anesthetized with chloralose were used for the experiments. Following a control period the cats were bled approximately 25 % of the blood volume. The total liver blood flow decreased in parallel to the mean arterial blood pressure, due to a large decrease in portal flow, whereas the hepatic arterial flow remained constant. Thus the splanchnic vascular resistance was not changed, the hepatic arterial resistance decreased, and the gastrointestinal resistance increased after the hemorrhage. Also the portal venous resistance was significantly increased. The hemorrhage resulted in hepatic glycogenolysis and peripheral glycolysis, but neither the splanchnic elimination of ethanol, consumption of oxygen nor hepatic dye elimination was decreased, and the hepatic redox level remained unaltered. The results indicate that although hemorrhage is accompanied by marked changes in hepatosplanchnic hemodynamics the intrahepatic distribution of blood flow is not subject to gross alterations.
Uncompetitive Character of Inhibition by Prostaglandin E., of the Enhancing Effect of a‐Adrenoceptor Blocking Drug on Noradrenaline Secretion in Isolated Guinea‐Pig Vas Deferens
Authors: Stjärne Lennart
Published: December 2008

STJÄRNE, L. Uncompetitive character of inhibition by prostaglandin E, of the enhancing effect of u‐adrenoceptor blocking drug on noradrenaline secretion in isolated guinea‐pig vas deferens. Acta physiol. scand. 1973. 89. 278–282.

Prostaglandin E2 has been shown to antagonize the enhancing effect of α‐adrenoceptor blocking drugs on the nerve stimulation induced secretion of sympathetic neurotransmitter. In the present study the antagonism by PGEa of the effect of the α‐adrenoceptor blocking chug pheritolainine on the secretion of noradrenaline from isolated superfused guinea‐pig vas deferens was found not to be competitive; the two agents clearly have different targets of action on sympathetic neurotransmitter secretion. In other experiments it has been shown that prejunctional α‐adrenoccptors may be involved in the control of the secretion of noradrenaline from sympathetic nerves by a dual mechanism, one dependent and one independent of endogenous prostaglandins. The present results may imply that these physiological control mechanisms are complementary, and directed towards different targets in neuronal excitation‐secretion coupling.
Sympathectomy and Pharmacological Blockade in Trained Rats
Authors: Ekblom B. , Kilbom A. , Malmkors T. , Sigvardsson K. , Svanfeldt E.
Published: December 2008

Several investigations have beer1 made, both in humans and in animals, to analyze the mechanisms causing the resting bradycardia and the relative bradycardia during exercise evoked by physical training. Sortie investigators have used trained rats for this purpose, although only with iiieasureriicnts of heart rate at rest (Östinan arid Sjöstrand 1971, Tiptori 1965).

In this study nieasurements of the heart rate of rats were made at different levels of exercise before and after training‐. The purpose was to exarriine the effectiveness of running on a treadmill in producing relative bradycardia during exercise. Further investigations about the bradycardia of training were also made by performing work tests after pharinacological blockade o f the different portions of the autonomic nervous system.
Release of3H‐Noradrenaline from Incubated and Superfused Rabbit Pulmonary Artery
Authors: Nedergaard By Ove A. , Schrold Jørgen
Published: December 2008

Nedergaard, O. A. and J. Schrold.Release of 'H‐noradrenaline from incubated and superfused rabbit pulmonary artery.Acta physiol. scand. 1973.89.296–305.

The quantitative release of (‐)‐3H‐noradrenaline (3H‐NA) from rabbit pulmonary artery was studied and a comparison made between a superfused strip and an incubated ring preparation. Two rings, but only one strip, could be derived from a single pulmonary artery. The postganglionic, adrenergic neurones were loaded with:,H‐NA and the release of tritium caused by either transmural stimulation or drugs was followed by fractional collection. The concomitant tension response was also monitored. The amount of tritium released per ml fraction elicited by transmural stimulation, nicotine and tyramine were 1.5, 2.5 and 5 times higher, respectively, using the incubated ring. Total tritium release induced by transmural stimulation or nicotine was equal using the two methods. In contrast, the release caused by tyramine was 2.7 times higher with the incubated ring preparation. Retention of3H‐tyramine by the superfused strip was slightly higher compared to the incubated ring. The sensitivity of the smooth muscle to cither exogenously added or endogenously released noradrenaline, evaluated by contractile tension response, was the same for both methods. It is concluded that the incubated ring preparation is better suited for release studies with the indirectly acting sympathomimetic amine, tyramine. Furthermore, the use of the ring method is considered advantageous from a practical point of view since it allows for a better experimental design and yields higher amounts of collected tritium per ml.
On the Possible Role of Bradykinin in Functional Hyperemia of Cat's Stomach
Authors: Fasth S. , Martinson J.
Published: December 2008

Fasth, S. and J. Martinson. On the possible role of bradykinin in functional hyperemia of cat's stomach. Acta physiol. scand. 1973. 89. 334–341.

The reactions of the consecutive vascular sections of the stomach were studied with a plethysmography technique at “rest”, during graded and maximal vasodilatation induced by isoprenaline and during infusion of bradykinin, supposed to be involved in functional hyperemia evoked by vagal nerve stimulation. It is shown that the stomach has a great capacity to maintain a rather constant area for filtration even during large variations in peripheral resistance. Bradykinin evoked an atropine resistant vasodilatation. This is similar to the effect of vagal stimulation. In contrast bradykinin did not increase capillary permeability which is one effect recognized for vagal stimulation. It is concluded that this plasmakinin may not play a role of mediator of functional hyperemia in the stomach since the whole pattern of vascular effects known for vagal stimulation is not reproduced.
Effect of Albumin Concentration and Colloid Osmotic Pressure on Albumin Synthesis in the Perfused Rat Liver
Authors: Dich J. , Hansen S. E. , Thieden H. I. D.
Published: December 2008

Dich, J., S. E. Hansen and H. I. D. Thieden. Effect of albumin concentration and colloid osmotic pressure on albumin synthesis in the perfused rat liver. Acta physiol. scand. 1973. 89. 352–358.

The effect of the albumin concentration and the colloid osmotic pressure on the rate of albumin synthesis was investigated in the perfused rat liver. The albumin concentration and the colloid osmotic pressure were changed independently. With the same concentration of albumin the rate of albumin synthesis decreased 20 to 30 per cent when the colloid osmotic pressure was increased by addition of gammaglobulin. It is concluded that the rate of albumin synthesis may be regulated by the colloid osmotic pressure. The albumin concentration seems to play a role in regulation only through the contribution to the colloid osmotic pressure.
Analysis of Threshold Currents during Myostimulation of Fibres in the Spinal Cord
Authors: Roberts William J. , Smith Dean O.
Published: December 2008

W. J. Roberts and D. O. Smith. Analysis of threshold currents during micro‐stimulation of fibres in the spinal cord. Acta physiol. scand. 1973. 89. 384‐ 394.

Fillies within the dorsal spinocerebellar tract of the cat were stimulated with current pulses from a mirroelertrode. With precise tracking, single nodes of Rainier of a fibre could be localized and the current required for activation studied as a function of the electrode position. The threshold stimulus amplitude was found to increase nonlinearly with distance from the node. The rate of increase in threshold was found to be less pronounced when the position of the electrode tip was changed axially rather than transversely to the node. The rates of increase with distance tended to decrease as the estimated fibre diameter became larger.
Effects of Mg2+ and Ca2+ on Noradrenaline Release and Uptake in Adrenergic Nerve Granules in Different Media
Authors: Euler U. S. von , Lishajko F.
Published: December 2008

Euler, U. S. V. and F. Lishajko. Effects of Mg2+ and Ca2+ on noradrenaline release and uptake in adrenergic nerve granules in different media. Acta physiol. scand. 1973. 89. 415–422.

Uptake and release of noradrenaline (NA) from a suspension of storage granules from bovine splenic nerves was measured after incubation in various media and effects of added Mg2+ and Ca2+ observed. No significant differences in NA release rate were observed in different media when NA uptake was prevented by addition of potassium ferricyanide to the medium. Uptake was facilitated by phosphate ions 5–30 mM but counteracted by monovalent cations. In sucrose‐phosphate media uptake of NA almost balanced spontaneous release. Mg2+ and Ca2+ had only a small action on NA release in the absence of NA uptake. In sucrose phosphate media Mg2+ facilitated uptake, whereas Ca2+ enhanced NA release. This action was associated with the formation of a calcium phosphate precipitate. No release or uptake of NA was observed during incubation at ice‐water temperature, nor did Mg2+ or Ca2+ have any effect. The results tend to show that release and uptake of NA in storage granules are separate, temperature‐dependent processes, influenced by mono‐ and divalent cations and phosphate ions.
Vascular Reactions in the Small Intestine during Vasodilatation
Authors: Biber Björn , Fara John , Lundgren Ove
Published: December 2008

The reactions within the consecutive vascular sections of the small intestine of the cat were studied during vasodilatations induced by secretin and cholccystokinin, infused i.a. or released “endogenously”, or by transmural electrical field and mucosal mechanical stimulations. All these potentially “physiological” stimuli evoked a response pattern similar to that of i.a. infused 5‐hydroxytryptamine and characterized by a relaxation of the resistance vessels as well as of the precapillary “sphincters”, as reflected in an increased capillary filtration coefficient. A small increase of regional blood volume was also observed during most vasodilatations. On the basis of these experiments it is impossible to exclude any of the abovementioned mechanisms in the discussion of the cause of the functional hyperemia of the gut. It is proposed that this vasodilatation depends partly upon a release of intestinal hormones, partly upon local mechanisms evoked by mechanical and possible also by chemical stimulation of the intestinal mucosa.
A Study on the Action of Noradrenaline on Ionic Content and Sodium, Potassium and Chloride Effluxes in the Rat Portal Vein
Authors: Wahlström By Bo A.
Published: December 2008

The effects of noradrenaline on the sodium, potassium, chloride and calcium content were studied. It was found that incubation in noradrenaline solution (6 μM) for 30 min caused a decrease in CI content from 86 mmol/kg wctweight to 80 mmol/kg wetweight, while the Ca content increased from 4.1 to 6.7 mmol/kg wetweight. There were no changes in the Na or K. content.

When noradrenaline, 6μM, was added during the washout of 36Cl, the rate of flux of 36Cl increased by 85%. This effect was dose‐dependent in the range 0.06 to μM, while a higher concentration had a less than maximal effect on the rate of flux. Noradrenaline increased the rate of flux of 42‐K as well, but this effect was small (15–20 %) and independent of dose. There was no effect of the drug on ‐4Na efflux. Flux data were used to calculate ion permeabilities and membrane potential in the presence of noradrenaline, taking into account the depolarization caused by the drug. The ratio PK: Pna : Pcl was 1 : 0.063 : 3.85 and the predicted membrane potential –27.55 mV, The membrane potential recorded by intracellular microelectrodes was ‐25 mV during noradrenaline stimulation. The shown effects of noradrenaline were blocked by phenoxybenzamine, while propranolol had no effect. It was concluded that the change in chloride permeability tan satisfactorily explain the depolarization (α‐action) caused by noradrenaline.
Autoregulation of Blood Flow in Human Adipose Tissue
Authors: Henriksen Ole , Nielsen Steen Levin , P. Paaske William
Published: December 2008

The presence of autoregulation of blood flow was investigated in subcutaneous adipose tissue of the distal part of the forearm by means of the local xenon‐133 washout technique. 89 studies were performed on 4 healthy subjects. Blood pressure changes were obtained by passive displacement of the investigated area to various test levels above and below the reference level, the jugular notch. Above heart level, where venous pressure was constant, elevation of the arm to a level corresponding to an arterial blood pressure reduction of 20 mm Hg did not alter adipose tissue blood flow. At higher elevation autoregulation was not seen as blood flow fell in proportion to the reduction in perfusion pressure. Below the heart, where arterial and venous pressures in the forearm increase in parallel, blood flow in subcutaneous tissue remained constant. This indicates adjustments in arteriolar resistance to oppose the distending force of the increased transmural pressure. In this orthostatic pressure range blood flow was maintained until a level corresponding to an increase in pressure of about 15 mm Hg beyond which blood flow was reduced to about 60 per cent.