bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of CI‐ and other Anions in Active Na+ Transport in Isolated Frog Skin
Authors: Huf ErnstG.
Published: December 2008

Huf, E. G. The role of CI and other anions in active Na* transport in isolated frog skin. Acta physiol. scand. 1972. 84. 366–381.

Skins of several amphibian species were kept between hemi‐chambers in solutions of identical SO42 Ringers' solutions with, or without mannito! (SM, S). When steady state was reached the SO‐i2˜ ions were replaced by equivalent amounts of one of the following anions (A): Cl−, HCO3k, NO3. Replacements were made in sequence, on the outside (o), the inside (i), and both sides of the skin, with periods of SO42 solutions on both sides between the several phases. In other experiments skin pairs were set up for simultaneous Na 24 and CI35 influx and out‐flux measurements. In all experiments, measurements on short circuit current (SCC) and open skin PD (E) were made, and from this total skin conductance (GT) data were calculated, as were values for E\a and Gaxa‐ From these data it is concluded that CI; (with SM0) leads to stimulation of Na* influx and net Na* flux resulting from epithelial swelling; increase in SCC; E; GT; E\a Gaxa‐The order of effectiveness of Af on electrical parameters was Cl− > NO3 > HCO3. Cl0 (with Clf) resulted in: a) “shunting” of Exa; b) depression of Na* influx, of SCC, E, Exa, G\\a; c) Cl0 (with SMj) seemed to stimulate Na* influx, but the flux data were as yet inconclusive. There were marked skin species differences. Best recoveries of starting values were obtained with skins of R. esculenta. Increases or decreases in Na* influx did not correlate with changes in Na* outflux, Cl− influx and Cl− outflux. Possible sites of A”‐membrane interactions involving the Na* transport system are discussed. Work by others is confirmed that in skins of R. esculenta, bathed in SO‐12 Ringer's with 4 mM Cl−, Cl− is actively transported in the inward direction at a level of approximately 109rof the active inward Na* transport.
Influence of Plasma Hypertonicity on Blood Viscosity Studied in Vitro and in an Isolated Vascular Bed
Authors: Rasmussen Sven Nybo
Published: December 2008

The effects of plasma hypertonicity on blood viscosity have been examined in vitro as well as in a vascular bed. NaCl was added to ox‐blood to produce plasma osmolalities up to about 1000 mosm/kg. The isolated rabbit ear was perfused at 70 and 30 mm Hg. Apparent viscosities of blood relative to plasma were calculated from the corresponding flow ratios (‘in vivo’ viscosity). Relative viscosities in vitro of the perfusates were determined by means of a cone‐plate viscometer. Blood viscosity measured ‘in vivo’ as well as in vitro was significantly increased by increasing osmolality. Maximal increments (almost 100 per cent) were observed between 700 and 900 mosm/kg. Plasma viscosity and vascular resistance was not influenced by hypertonicity. Viscosities ‘in vivo’ were generally lower than in vitro–the discrepancy was more pronounced at 70 than at 30 mm Hg and was greater in isotonic than in hypertonic blood. The effect of hypertonicity on blood viscosity is explained mainly by a reduced deformability of the hypertonically crenated red cells. It seems likely to explain the inverse relationship between renal medullary blood flow and medullary hypertonicity (Thurau et al. 1960) as caused partly by passive mechanisms involving blood viscosity changes with varying osmolality.
Proton‐ and Carbamino‐linked Oxygen Affinity of Normal Human Blood
Authors: Garby L. , Robert M. , Zaar B.
Published: December 2008

The oxygen affinity of normal human blood was measured at two different pH values and three different pCO2 values over the whole saturation range. From these data, and from data on the interaction of 2,3‐diphosphoglycerate with hemoglobin, values were calculated for the proton‐linked oxygen affinity at different pCO2 values and for the carbamino‐linked oxygen affinity at different pH values. Both the proton‐linked and the carbamino‐linked oxygen affinity were found to be markedly dependent on the degree of oxygen saturation. The relative contribution of the three ligands, i.e. protons, carbon dioxide and 2,3‐diphosphoglycerate, to the classical Bohr effect was estimated and found to be dependant on the oxygen saturation level. The values for the proton‐linked oxygen affinity and the carbamino‐linked oxygen affinity were found, by applications of Wyman's reciprocal relations and 2,3‐diphosphoglycerate binding data, to give good estimates of the oxygen‐linked proton binding and the oxygen‐linked carbamino binding. The data show that the oxygen‐linked carbamino reaction takes place mainly during the binding of the first 2 oxygen molecules with a value of about 0.25 mol per mol of oxygen. The proton release accompanying this reaction was estimated to be 1.3–1.7 mol per mol.
Bretylium and the Supersensitivity to Exogenous Noradrenaline after Sympathetic Denervation Studied in the Conscious Rat
Authors: Lundberg Dag
Published: December 2008

Rats denervated by excision of the superior cervical sympathetic ganglion and given reserpine at the time of operation were used. The width of the palpebral aperture, which reflects the tone of the sympathetically innervated periorbital smooth muscle, was measured in the conscious rats after differenti.p.doses of 1‐noradrenaline. The sensitivity of the muscle to exogenous noradrenaline was thus tested during 3 periods of 3 h duration each between 13 and 30 h after denervation. Bretylium, which is known to delay the degeneration contraction of the muscle,i.e.the degeneration transmitter release, postponed the development of denervation supersensitivity. Hence, bretylium seems to preserve temporarily both the amine storage mechanisms and the axonal amine pump in the degenerating adrenergic nerve terminals.
Prostaglandin Induced Inhibition of Neurotransmission in the Isolated Guinea Pig Seminal Vesicle
Authors: Hedqvist Per
Published: December 2008

The contractile response of the guinea pig seminal vesicle to postganglionic nerve stimulation is inhibited by prostaglandin Ei and E2 in low doses and potentiated by high doses. Prostaglandin Ei and E2 consistently increase the contractile response to exogenous noradrenaline. The potentiation by high doses of prostaglandin Ei of the effector response to nerye stimulation is antagonized by SC 19220, inhibitor of prostaglandin action. The effect of prostaglandin Ei and E2 on the neuroeffector system of the seminal vesicle may be explained by a dual action, inhibition of noradrenaline release from the nerve terminals and potentiation of the effector response to the noradrenaline released. An endogenous prostaglandin‐mediated regulation of the smooth muscle response to nerve activity is suggested.
Influence of Extracellular Calcium on Isometric Force and Velocity of Shortening in Depolarized Venous Smooth Muscle
Authors: Hellstrand Per , Johansson Borje , Ringberg Anita
Published: December 2008

The Ca++ dependence of the contracture response obtained in depolarized smooth muscle from rat portal vein was studied. Double reciprocal plots of isometric force versus [Ca++]n were examined by linear regression analysis for n = 1, 2 and 3. The data were consistent with a linear relationship for n = 2. This may be taken to indicate that isometric force is regulated by the binding of two calcium ions to an unknown “receptor compound” in the tissue. In other experiments the velocity of shortening was studied by the method of quick release after the muscles had developed isometric contractures in 2.5 or 0.4 mM [Ca++]0, respectively. The mean isometric forces elicited by these 2 levels of [Ca++]0 differed by a factor of 1.7, but the shortening velocities at comparable relative loads were essentially the same. These results may be considered in the light of recent studies of striated muscle which have been concerned with the problem whether Ca++ determines exclusively the number of activated cross bridges in the sliding filament system or whether it also influences the rate of movement of the individual cross bridge.
Catecholamine Storing Cells in Human Fetal Superior Cervical Ganglion
Authors: Hervonen A. , Kanerva L.
Published: December 2008

The distribution and structure of small, intensively fluorescent, granule‐containing cells within the human feta! ganglion cenicale superius was studied. The ganglia contained numerous small collections of these cells evenly scattered over the whole region of the organ. The granule‐containing cells were as a rule located on the capillaries and showed regularly tight contacts with the basement membrane. The mean diameter of the catecholamine storing granules was 2700 A. The differentiation and role of the granule‐containing cells within sympathetic nervous system was discussed.
Assay of the Transformation of Collagen in situ
Authors: Heikkinen E. , Ivaska K. , Kulonen E.
Published: December 2008

Skin extract of newborn rats increases the insolubilization of collagen in skin slices in vitro. The effect is destroyed by heating and inhibited by lathyrogens. Purified collagen in the precipitated form is. on the contrary, transformed to the more soluble forms by skin extract.
Properties of Cortical Group I Neurones Located in the Lower Bank of the Anterior Suprasylvian Sulcus of the Cat
Authors: Silfvenius H.
Published: December 2008

Recordings were made from 134 cortical cells of the forelimb group I locus in the lower bank of the anterior suprasylvian sulcus in chloralose anesthetized cats. The cells were studied with regard to their connexions with group I and II muscle‐, skin‐ and joint afferents in the contralateral limbs and with auditory and visual afferents. 62 cells were excited by forelimb group I afferents, two of them additionally from corresponding hind limb afferents. Forelimb group II afferents co‐excited about 70 % of the cells. All group I activated cells were excited by low threshold forelimb skin afferents. Low threshold joint afferents did not influence group I cells. Forelimb high threshold joint afferents activated about 40 % of the group I neurones. Three types of forelimb short latency excitation motivated a classification of the cells as; primary cortical group I cells, primary cortical mixed cells and primary cortical cutaneous cells. Some group I cells were excited by different hind limb afferents. Only 8 of the group I cells were discharged by auditory or visual afferents. 9 cells were inhibited or received mixed inhibition‐excitation from group I forelimb afferents. The latencies of the group I inhibitory potentials suggested that they were evoked by cortical interneurones. Forelimb group II‐ and skin afferents converged with inhibition on the group I inhibited neurones. Cells uninfluenced by group I afferents received excitation from other afferents or did not respond to the inputs used. The results are discussed in relation to previous studies on forelimb group I projections.
Potentiation of the Gastric Secretory Response to Sham Feeding in Dogs by Infusions of Gastrin and Pentagastrin1
Authors: Sjödin Lars
Published: December 2008

The gastric acid secretory response to sham feeding in dogs provided with esophagostomies and Pavlov pouches was related to the length of the sham feeding period. In antrectomized dogs the response even to prolonged sham feeding (30 min) was small. When a small supra‐threshold dose (0.30 μg/kg/h) of synthetic human gastrin I or pentagastrin was infused, these dogs responded markedly to a short period of sham feeding (1 min), When the sham feeding period was prolonged to 10 min subthreshold amounts of gastrin and pentagastrin (0.06 μg/kg/h or less) sufficed to enhance the sham feeding response. The enhancement fulfilled the criterion proposed by Gaddum for true potentiation. The pepsin output was also increased when the sham feeding period was prolonged. In the antrectomized dogs pepsin output after sham feeding was not significantly changed when the dose of gastrin infused was increased from 0.06 to 0.30 μg/kg/h or when the dose of pentagastrin was increased from 0.30 to 1.20 μg/kg/h.
Recurrent Depression from Motor Axon Collaterals of Supraspinal Inhibition in Motoneurones
Authors: Hultborn H. , Udo M.
Published: December 2008

The recurrent effects from motor axon collaterals have been examined on inhibitory transmission to motoneurones from the cortico‐, rubro‐ and vestibulospinal tracts and a pathway descending in the medial longitudinal fasciculus. Disynaptic vestibulospinal IPSPs in knee flexor motoneurones were always considerably decreased by conditioning antidromic volleys. No recurrent effects were found on disynaptic IPSPs evoked from the medial longitudinal fasciculus or from the red nucleus in knee extensor motoneurones. The transmission of polysynaptic cortical and rubral IPSPs was sometimes recurrently inhibited but more efficiently in flexor motoneurones than in extensor motoneurones. Susceptibility to recurrent depression is taken to indicate that the descending IPSPs are mediated by Ia inhibitory interneurones since impulses in motor axon collaterals, via Renshaw cells, give rise to a selective inhibition of these interneurones. Those IPSPs which are unaffected by ventral root stimuli are assumed to be transmitted through other interneurones.
Effects of Colchicine, Vinblastine and Vincristine on Degeneration Transmitter Release after Sympathetic Denervation Studied in the Conscious Rat
Authors: Lundberg Dag
Published: December 2008

The effect of the mitosis inhibitors colchicine, vinblastine and vincristine on the time course of the degeneration contraction of the sympathetically innervated periorbital smooth muscle was studied in conscious rats. In conformity with earlier findings with colchicine, single s.c. doses of vinblastine (2–4 mg/kg) or vincristine (1–2 mg/kg) given at the time of axotomy delayed the start of the degeneration contraction,i.e. the leakage of sympathetic transmitter from the degenerating nerve endings. The significance for the delaying effect of the time interval between axotomy and injection of colchicine was studied in some detail. The delaying effect declined gradually with increasing time interval between denervation and injection. Colchicine given later than 4–6 h after axotomy did not delay. In view of this finding and the fact that the mitosis inhibitors used are known to inhibit the intra‐axonal microtubular transport of different nerve constituents it is proposed that the drugs postpone the degeneration transmitter release by slowing down the rate by which an “axotomy information” is transported distally along the neuron. The “axotomy information”, probably linked to some axotomy‐induced change in intra‐axonal structures related to the microtubules, seems to be transported at a rate of about 4 mm per hr. Local treatment of the decentralized superior cervical ganglion with colchicine or vinblastine induced a “degeneration” contraction probably due to a complete inhibition of the flow of some vital matter to the nerve endings.
Studies on Left Ventricular Receptors, Signalling in Non‐Medullated Vagal Afferents
Authors: ÖBerg Bengt , Thorén Peter
Published: December 2008

Left ventricular receptors, signalling in non‐medullated vagal fibres and displaying a low, irregular spontaneous activity, have been analysed by recordings of impulse activity in cardiac afferent nerves. The receptors were distributed diffusely all over the ventricle and in both superficial and deep layers of the myocardium. They were activated by occlusions of the ascending aorta, by substantial elevations of arterial blood pressure and by rapid infusions of saline or dextran, whenever these procedures produced a clearcut increase of intraventricular diastolic pressure and end‐diastolic volume. The endings were also excited by veratrum alkaloids, nicotine and digitalis alkaloids. When activated, the receptors usually displayed a cardiac rhytm, but with intense stimulation the activity usually became continuous. The receptors evidently function as mechano‐ or deformation receptors, responding primarily to a distension of the ventricle. Activation of the receptors causes a reflex bradycardia and, in all probability, vasodilatation and blood pressure fall. They may contribute to the homeostatic control of blood pressure and blood volume, but their main function seems to be to protect the heart frome.g. imminent overloading. The endings are probably of main importance for the emergence of the Bezold‐Jarisch reflex.
Intracranial Pressure in Conscious Rabbits after Decentralization of the Superior Cervical Sympathetic Ganglia
Authors: Edvinsson L. , Owman Ch. , West K. A.
Published: December 2008

The intracranial pressure, measured as the ventricular fluid pressure, was recorded continuously during about 2 days in conscious rabbits at various time‐periods after bilateral decentralization (preganglionic denervation) of the superior cervical sympathetic ganglia. The pressure recorded 5 h after the operation was initially unchanged compared with non‐denervated control animals. During the following day it increased by approximately 50 mm physiological saline. The pressure was elevated (by approximately 25 mm saline) also 6 days after the operation. At 2 weeks it had returned to almost the same level as in the non‐denervated controls. It is suggested that the alterations in the ventricular fluid pressure mainly reflect changes in the cerebral blood volume, although direct effects on the sympathetically supplied choroid plexuses cannot be excluded.
Hemodynamic Responses of Relaxed and Shivering Hypothermic New‐Born Lambs
Authors: Koivikko Antti , Lånsimies Esko
Published: December 2008

The hemodynamic responses to hypothermia and shivering were investigated in 4 relaxed, in 9 deeply anesthetized and 9 lightly anesthetized new‐born lambs. Muscle‐relaxation and deep anesthesia prevented the increases of the oxygen consumption and the cardiac output. In shivering lambs these parameters increased. Correction of metabolic acidosis increased temporarily the cardiac outputs. The cardiac responses to cold stress of the relaxed and deeply anesthetized lambs differed from that seen in the relaxed adult dogs but were similar to those observed in relaxed, β‐blocked dogs. This difference may be due to some kind of immaturity of the β‐adrenergic system in the new‐born period.
The Pressure‐Flow Relationship in Renal Cortical and Medullary Circulation
Authors: Grängsjö G. , Wolgast M.
Published: December 2008

The perfusion pressure‐red cell flow relationship in the cortical and in the outer and inner medullary circulation has been investigated on 9 chloralos anesthetized mongrel dogs using an indicator‐dilution technique with 32‐P labelled red cells and internal detection with small needle‐shaped semiconductor detectors. The perfusion pressure was varied by a clamp on the aorta. High pressures were obtained by ligation of the carotid arteries and section of the vagal nerves preceded by denervation of the renal nerves. The change in red cell flow on changing the perfusion pressure was determined from 1. the change in the regional mean transit time and 2. the change in regional red cell volume. The flow in all the regions studied was then found to be lineary related to the perfusion pressure up to some 70 mm Hg, whereas in the pressure range between 70 and 200 mm Hg it remained essentially unchanged. The findings indicate an autoregulative response in both the cortical and medullary circulation.
A Note on the Influence of Asynchronous Activation on Myocardial Contraction
Authors: Jóhannsson M. , Nilsson E.
Published: December 2008

Pairs of rabbit papillary muscles were mounted in series to make it possible to study the effects of asynchronous activation on myocardial contraction. The two muscles were connected together via platinum loops hooked to a lever (displacement transducer), the other end of each muscle being fixed to a force transducer. The force of each muscle was measured at various contraction frequencies with the lever fixed (isometric contractions) or freely movable (auxotonic contractions). With auxotonic contractions, asynchronous activation (25 or 50 ms interval between stimulation of the two muscles) increased the movements of the muscles, decreased their force, and prolonged the duration of the contraction at 37°C. These effects were greater, the higher the contraction frequency within the range 30–150 beats/min. On the basis of these results, it is suggested that the physiological asynchrony of the myocardial contraction in vivo tends to offset frequency‐induced changes at the cellular lever (enhanced intensity of active state, shortening of active state duration).
Secretion from the Dog's Parotid at Different Time Intervals after Denervation
Authors: Holmberg Jan
Published: December 2008

Previous observations suggest that cholinergic secretory fibres reach the dog's parotid gland not only via the auriculo‐temporal nerve but also along the internal maxillary artery. 3–5 days after section of both these sets of nerves citric acid applied to the oral mucosa was found to evoke slow secretion only, or none at all. It has been reported, however, that the secretory response elicited reflexly after auriculo‐temporal nerve section gradually increases during the days following the operation. The auriculo‐temporal nerve was divided unilaterally in one group of dogs, and in another group this operation was combined with section of the nerves on the internal maxillary artery. During the following five weeks the dogs were examined repeatedly. Each time the secretory innervation was studied in two ways: by pouring citric acid into the mouth and by injecting esenne through the salivary duct into the gland. In addition the secretory responses to methacholine were estimated. The results indicate that postoperatively there was first a period in which there wag some increased release of acetylcholine in the gland (a “degeneration phenomenon”); supersensitivity then developed in the secretory cells. In spite of these complications both methods to study the secretory innervation could be used after the first week and onwards to demonstrate the difference in the effectiveness between the two denervation procedures.
Studies of Blood‐pressure Regulation IV. The Effects of Impulse Train Stimulation of the Carotid‐sinus Nerves
Authors: Jonzon A. , ÖBerg P. Å. , Sedin G. , Sjöstrand U.
Published: December 2008

The effect of sinus nerve stimulation on the blood pressure and heart rate was studied in dogs. Electrical stimulation of the sinus nerves of both sides was given both in the form of 2 types of intermittent impulse trains and as impulses of constant frequency. The intermittent impulse bursts, which were synchronized with the ECG, comprised 5–50 imp which coincided with systole (150 ms). Comparisons were made between stimulation with a constant frequency and the intermittent types, with the same number of impulses per cardiac cycle. It was found that the maximal blood pressure reduction was already reached at 5–10 imp per cardiac cycle. The difference between stimulation with a constant frequency and the intermittent types, with the same number of impulses per cardiac cycle, is negligible as regards blood pressure reduction but the intermittent type has a greater effect on the heart rate. Sinus nerve stimulation in massive haemorrhage and the influence of the amplitude of the stimulation signal were also studied.
Gastric Absorption of L(+) and D(‐) Lactic Acid and their Effects on the Transmucosal Ion Transport in Innervated, Non‐secreting Cat Stomachs
Authors: Frenning Bertil
Published: December 2008

On instillation of 170 mM lactic acid (L or D) into unstimulated whole stomach pouches in cats the hydrogen ion concentration decreased more slowly than on instillation of 170 mM hydrochloric acid. When 700 mM lactic acid (L or D) was instilled the reverse was found. On instillation of 170 mM HCI subsequent to an instillation of 170 mM lactic acid (L or D) the changes in concentration of eleotrolytes as well as the net fluxes of electrolytes were of the same order of magnitude as during a preceding control instillation of HCI. On instillation of 170 mM HCI subsequent to an instillation of 700 mM lactic acid (L or D) the decrease in hydrogen ion concentration and the increase in sodium ion concentration were significantly larger than in the control instillation of HCI. The net influx of sodium ions was significantly increased but not the net efflux of hydrogen ions. After exposure of the gastric mucosa to 700 mM lactic acid (L or D) it produced a mucoid fluid that contained mainly sodium and chloride ions. This explained the results obtained when HCl was instilled subsequent to an instillation of 700 mM lactic acid. No morphological changes were found on examination in the scanning electron microscope of gastric mucosae exposed to 6 ml of 700 mM L lactic acid.
Centrally Mediated Effects of Sodium and Angiotensin II on Arterial Blood Pressure and Fluid Balance
Authors: Andersson B. , Eriksson L. , Fernández O. , Kolmodin C.‐G. , Oltner R.
Published: December 2008

Four kinds of infusions were made for 1 h periods into the 3rd cerebral ventricle of hydrated, conscious goats: 1) Angiotensin in hypertonic NaCI, 2) angiotensin in slightly hypotonic NaCI, 3) angiotensin in isotonic d‐glucose, and 4) hypertonic NaCI. The influence of these infusions on carotid blood pressure and fluid balance was studied. The infusions of angiotensin in hypertonic NaCl had conspicuous hypertensive, dipsogenic, antidiuretic and natriuretic effects. More moderate responses of the same kinds were obtained during the infusions of hypertonic NaCl and of angiotensin in slightly hypotonic NaCI. In contrast, no or only weak effects were obtained by the infusions of angiotensin in isotonic d‐glucose. The results are taken as support for the idea that a Na+sensitive system in the vicinity of the 3rd ventricle may be of importance in the central contml of fluid balance and arterial blood pressure. Such a system may be influenced by the Na+concentration of the cerebrospinal fluid, and angiotensin may either sensitize it to Na+ or make it more exposed to Na+ions.
Vagal and Sympathetic Efferent Discharge in the Bainbridge Reflex of Dogs
Authors: Hakumäki Martti O. K.
Published: December 2008

A study has been made of the response in vagal and sympathetic cardiac efferentation to i.v. injection, in Bainbridge type experiments on dogs anesthetized with i.v. chloralose. Cardiac vagal efferent activity was recorded from the cervical vagus, and sympathetic cardiac efferentation from the postganglionic cardiac fibres. An increase in sympathetic cardiac discharge, along with diminution in the vagal cardiac discharge, with associated tachycardia, has been detected in the Bainbridge reflex of dogs. A positive linear correlation was observable between the heart rate and the ratio of sympathetic and vagal number of impulses. The acid‐base balance of the experimental animal was controlled.
In Vitro Work Load and Rat Heart Metabolism: II. Effect on amino acid transport
Authors: Ahrén K. , Hjalmarson Å. , Isaksson O.
Published: December 2008

In vitro pressure overload was found to accelerate protein synthesis in the isolated working rat heart (Hjalmarson and Isaksson 1972 a). Since membrane transport of amino acids is considered to be one rate‐limiting step in protein synthesis, the amino acid transport in the isolated rat heart was investigated using the non‐utilizable amino acids α‐aminoisobutyric acid (AIB) and 1‐aminocyclopentane carboxylic acid (cycloleucine). Increased pressure load (afterload) accelerated amino acid uptake after a perfusion period of 15 ruin, and a 50—100% increase in the intracellular to extracellular distribution ratio of the amino acids was seen after 60 min of perfusion. This accelerated uptake was not inhibited by cycloheximide, suggesting that the work load effect was not dependent upon a continuous synthesis of proteins. The accumulation rate continued to be stimulated for some time after normalization of the work load and coronary flow, indicating that the work load effect was not directly linked to coronary flow. Increased preload did not stimulate amino acid uptake. Hearts from hypophysectomized rats showed a decreased concentrative uptake but the amino acid uptake was still accelerated by pressure overload. It is suggested that an increased uptake of amino acids could be of physiological significance in relation to the increased protein synthesis under these conditions.
The Release of Protein in the Course of Catecholamine Secretion from Bovine Adrenals Perfused in Vitro
Authors: Serck‐Hanssen Guldborg
Published: December 2008

The release of protein from chromaffin granules during catecholamine secretion has been studied in bovine adrenals perfusedin vitro. In response to acetylcholine an increased output of catecholamines as well as protein from the glands occurred. Secretion caused a reduction in protein content of chromaffin granules corresponding to the amount of amines released. The quantity of protein released during secretion from the large granule fraction, the fraction containing the chromaffin granules, was of a magnitude compatible with secretion of the total content of water‐soluble protein in the chromaffin granule. These observations are consistent with an all‐or‐none release mechanism for the adreno‐medullary chromaffin granules.
Choline Acetyltransferase in the Normal and Parasympathetically Denervated Parotid Gland of the Dog
Authors: Ekström Jörgen , Holmberg Jan
Published: December 2008

The reduction of the activity of the acetylcholine‐synthetizing enzyme, choline acetyltransferase, has been used as an indicator of the effectiveness of the denervation obtained by various operative procedures in the parotid gland of the dog. After division of the auriculo‐temporal nerve about 30 % of the normal enzyme activity still remained in the gland A reduction of the activity to about 10 % was obtained when both this nerve and the recently described secretory nerves on the internal maxillary artery had been cut. When in addition to these two sets of nerves, the facial nerve was severed as well, the choline acetyltransferase activity was not measurable. Electrical stimulation of the facial nerve was found to provoke a slight secretion from the gland.
Histochemical Studies of Uterine Innervation after Neurectomies
Authors: Kanerva Lasse , Mustonen Tapio , Teräväinen Heikki
Published: December 2008

The distribution of nerves of the uterus containing acetylcholinesterase (AChE) and catecholamine (CA) was studied with light microscopic histochemical techniques after sympathectomy, parasympathectomy, and removal of the paracervical ganglion in the rat. A rich plexus of AChE‐containing nerves was present both in the myometrium and around the uterine blood vessels. Nerve fibres exhibiting CA fluorescence were abundant around the blood vessels, but only sparse in the myometrium. Sympathectomy resulted in the disappearance of CA‐containing perivascular nerve fibres but left intact the extravascular myometrial nerve fibres: those containing CA and those containing AChE. Parasympathectomy caused a slight decrease in the perivascular AChE‐containing fibres. On the other hand it had no effect on the myometrial AChE‐ or CA‐containing nerve fibres. Bilateral destruction of the paracervical ganglion resulted in the complete disappearance of AChE‐ and CA‐containing fibres, both around the blood vessels and in the myometrium.
Enhancement by Indomethacin of Cold‐Induced Hypersecretion of Noradrenaline in the Rat in vivo ‐ by Suppression of PGE Mediated Feed‐back Control?
Authors: Stjärne Lennart
Published: December 2008

While indomethacin treatment did not alter the urinary excretion of noradrenaline in the rat at room temperature, it consistently and significantly augmented the urinary hyperexcretion of noradrenaline induced by exposure to cold; the excretion of adrenaline remained initially unchanged. The effect of indomethacin increased progressively with time during the experimental period of about one week. The results imply that indomethacin, which is known to be able to block the formation of PGE in vivo as well as in vitro, augments the secretion of nor‐adrenaline from sympathetic nerves during sympathetic hyperactivity. Since the amount of noradrenaline secreted as a result of nerve stimulation is raised when PGE formation is depressed, in isolated tissues in vitro, the present result may imply that the sympathetic hyper‐secretion induced by indomethacin was secondary to suppression of PGE formation.
Extent of Engagement of Various Cardiovascular Effectors to Alterations of Carotid Sinus Pressure
Authors: Kendrick Ed , Oberg Bengt , Wennergren Göran
Published: December 2008

Reflex adjustments of blood pressure, heart rate, skeletal muscle and renal resistance vessels to changes in intrasinusal pressure were recorded and the respective sinus pressure—reflex response curves plotted. In this way one could evaluate whether the various individual reflex arcs, which together constitute the baroreceptor reflex control of the circulation, display “threshold” response and maximal sensitivities, respectively, at identical sinus pressures.—The curves describing the blood pressure, muscle and renal resistance vessel responses were found to follow identical courses, while the heart rate response curve was displaced to the right of the others. This discrepancy is, however, in all probability a mere consequence of the peculiar neuro‐effector characteristics in the heart. The individual components of the baroreceptor reflex, therefore seem to be recruited simultaneously when the sinus pressure is increased, and there is thus nothing to indicate that afferents from low and high “threshold” baroreceptors, respectively, are preferentially distributed to different neuron pools in the bulbar cardiovascular centres.—A displacement of the response curves to the right was observed when

a) non‐pulsating sinus pressures were used instead of pulsating,

b) sinus pressures alterations were induced by lowering the pressure from higher levels instead of elevating it,

c) arterial PCO2 was increased.
Effect of Adrenaline on Amino Acid Transport in Perfused Rat Heart
Authors: Isaksson O. , Källfelt B.
Published: December 2008

Effects of adrenaline on amino acid transport in the isolated perfused rat heart was investigated using the non‐utilizable amino acidsα‐aminoisobutyric acid (AIB) and 1‐aminocyclopentanecarboxylic acid (cycloleucine). Adrenaline, addedin vitro, caused a dose dependent increase in the uptake of AIB and cycloleucine, and a significant stimulation was seen after 15 min of perfusion. The minimal effective concentration was 5 × 10‐8M, and an effect was obtained when hearts were perfused with glucose or palmitate as substrate and when no exogenous substrate was added. Adrenaline increased the uptake in hearts arrested with high [K+] or tetrodotoxin, and the accelerated uptake was not dependent upon the chronotropic effect of adrenaline. Under conditions when adrenaline increased amino acid uptake, protein synthesis was either unaffected or decreased. The data of the present study show that adrenaline directly stimulates amino acid transport in the heart and it is concluded that increased uptake of amino acids could be an energy‐generating system for the heart during adrenergic stimulation.
Steady State Contribution of the Na, K‐Pump to the Membrane Potential in Identified Neurons of a Terrestrial Snail, Helix pomatia
Authors: Christoffersen G. R. J.
Published: December 2008

The presence of an electrogenic Na, K‐pump has been demonstrated in identified neurons of the snail, Helix pomatia by the observation of ouabain sensitive hyperpolarizations following increases of intracellular sodium concentration. A contribution of the pump to the resting membrane potential (RMP) has been measured at varying extracellular potassium concentration as the depolarizing effect of ouabain upon RMP. The contribution was found to have a value of – 7 mV at 4 mM external potassium and to decline with increasing and decreasing K‐concentrations. The electrogenic flux has been calculated by two independent methods from measurements of membrane resistance and the electrogenic contribution to the RMP. Agreement was found when the flux was computed both from modified constant field equations and from Ohm's law. The flux increased from zero at 0 mM external potassium concentration to –10 peq cm–2 s–1 at 6 mM and stayed at this level with rising concentrations of K. It is concluded that the decrease of the electrogenic contribution to RMP observed at low K‐concentrations is caused by inhibition of the electrogenic flux whereas the decline of the contribution seen at higher K‐concentrations is due to a diminution of the membrane resistance (increment of potassium permeability) rather than to a fall of the electrogenic flux.
Cerebral Energy State and Cerebral Venous Po2 in Experimental Hypotension Caused by Bleeding
Authors: Eklöf Bo , Macmillan Vernon , Siesjö Bo K.
Published: December 2008

Arterial hypotension was induced by bleeding lightly anesthetized rats to mean arterial blood pressures of 60 and 45 mm Hg, respectively, with subsequent measurements of arterial and cerebral venous gas tensions, of extra‐ and intracellular acid‐base parameters, as well as of parameters necessary for an evaluation of the energy state of the brain tissue. In none of the groups were there significant changes in extra‐ or intracellular pH, indicating that a non‐chemical mechanism was responsible for the autoregulation of flow. Most of the animals in the 60 mm Hg group, and about half of those with a blood pressure of 45 mm Hg, showed a normal metabolic pattern in the brain. In the remaining animals, there were moderate in‐creases in lactate and, simultaneously, slight decreases in the charge potential of the adenine nucleotides of the tissue due to moderate increases in ADP and AMP. Such changes occurred at a venous Po, of about 25 mm Hg. Since other results indicate that the cerebral energy state fails at higher mean arterial blood pressures, and at higher Pvo, values, provided that the tissue is acidotic, it is concluded that the efficient energy homeostasis observed in the present experiments may have been due to the fact that no tissue acidosis developed.
The Effect of Bilateral Carotid Artery Ligation upon Acid‐Base Parameters and Substrate Levels in the Rat Brain
Authors: Eklöf Bo , Siesjö Bo K.
Published: December 2008

The effect of bilateral carotid artery ligation upon acid‐base parameters and substrate levels in the brain were studied in lightly anesthetized rats, either at normal blood pressure or after a reduction in blood pressure to 100 and 70 mm Hg, respectively. As evaluated arteriovenous differences the tissue CO2 tension was consistently higher than the Pco2 in cisternal CSF. At low blood pressures most animals showed a marked to excessive elevation of the tissue lactate content but since the CSF lactate content was only moderately increased it is concluded that a larger reduction in blood flow occurred in the supratentorial than in the infratentorial parts of the brain. At low perfusion pressures the tissue contents of glucose, α‐ketoglutarate and glutamate were considerably reduced. The results suggest that the experimental model used gave rise to an inhomogenous decrease in flow in the tissue, and a correlation between the increase in the lactate and the decrease in the bicarbonate contents suggests that a mixture of perfused and non‐perfused tissue areas may have existed.
Motoneurone Models Based on ‘Voltage Clamp Equations' for Peripheral Nerve
Authors: Kernell Daniel , Sjöholm Hans
Published: December 2008

Motoneurone models were developed by modifications of the Frankenhaeuser‐Huxley equations (1964) for voltage clamp data amphibian nerve fibre. The major modifications were: (i) that the subthreshold sodium inactivation was decreased, and (ii) that the Frankenhaeuser‐Huxley model was provided with a long‐lasting after‐hyperpolarization due to potassium permeability changes. Besides, model versions were developed that also had passive membrane properties (e. g. a resting membrane time constant) similar to those of spinal motoneurones. For various model versions, single spikes and the associated afterpotentials were shown in the present paper. The main aim was to use the motoneurone models for studies of repetitive impulse firing. This will be done in a subsequent paper (Kernell and Sjoholm 1972).
Glyoxylic Acid Condensation: A New Fluorescence Method for the Histochemical Demonstration of Biogenic Monoamines
Authors: Axelsson Sture , Björklund Anders , Falck Bengt , Lindvall Olle , Svensson Leif‐Åke
Published: December 2008

A new methodological approach to the fluorescence microscopical visualization of biogenic monoamines, based on condensation with gaseous glyoxylic acid, is presented. Glyoxylic acid treatment seems both to be more sensitive for the well‐known biogenic catecholamines and indolamines, and to allow the detection of other biogenic amines—such as melatonin—which are not demonstrable with available techniques.
Cerebral Blood Flow in Ischemia Caused by Carotid Artery Ligation in the Rat
Authors: Eklöf Bo , Siesjö Bo K.
Published: December 2008

In order to study if bilateral ligation of the carotid arteries, either alone or combined with moderate arterial hypotension is accompanied by a macroscopically uneven brain perfusion, the regional cerebral blood flow (rCBF) was measured using the antipyrine‐14C method with direct counting of the radioactivity in the tissue. Ligation of the carotid arteries at normal blood pressure decreased blood flow in the frontal‐parietal regions by about 50 % in both hemispheres. At a mean blood pressure of 100 mm Hg, the ligation caused a further reduction in flow but the results were variable and gross differences often occurred between the hemispheres. At 70 mm Hg in blood pressure carotid occlusion drastically reduced the frontal‐parietal rCBF but flow in the occipital and basal temporal regions was usually better upheld. It is concluded that in the rat, combined carotid artery ligation and moderate hypotension gives rise to a macroscopically inhomogenous reduction in rCBF, and that regions of nonperfusion may coexist with adequately perfused areas.
Increased N‐Acetylserotonin and Melatonin Formation Induced by d‐Amphetamine in Rat Pineal Gland Organ Culture via a β‐Adrenergic Receptor Mechanism
Authors: Bäckström Maria , Wetterberg Lennart
Published: December 2008

Dextro‐amphetamine (10–5M) added to the medium of rat pineal glands in organ culture produces an eightfold increase of radiolabeled N‐acetylserotonin and melatonin when tryptophan or serotonin are used as labeled precursors. In concentration of 10–4M d‐amphetamine causes a decreased formation of 5‐hydroxyindoleacetic acid from tryptophan and serotonin. Addition of d‐amphetamine to pineal glands also resulted in an increase of N‐acetyltransferase activity as compared with untreated glands. The effect of d‐amphetamine and noradrenaline was blocked by propranolol, a β‐adrenergic blocking agent but not by the α‐adrenergic blocking agent phentolamine. In cervical ganglionectomized rats the addition of d‐amphetamine to the culture medium did not produce an increase in N‐acetylserotonin production. Conversely noradrenaline added to the medium gave a high formation of N‐acetylserotonin. This indicates that the major effects of d‐amphetamine on pineal N‐acetyl‐transferase activity are mediated by noradrenaline.
The Linguo‐Chorda Tympani Reflex—an Electrophysiologically Undescribed Reflex
Authors: Hellekant Göran , Kasahara Yasuo
Published: December 2008

The impulse activity in the central part of the chorda tympani nerve of the rat was recorded during mechanical stimulation of the oral region. The results obtained at a stimulation rate of 1 Hz show that a) a reflex discharge could be recorded about 6–10 ms after stimulation of the ipsilateral side of the tongue, b) stimulation of the contralateral side increased the latency by about 1–1.5 ms, c) the reflex could be evoked in animals which showed no spontaneous efferent activity in the chorda tympani nerve, d) recordings from nerve filaments showed that a filament could display spontaneous activity without being involved in the reflex, e) the lingual nerve serves as the main sensory link on the reflex to mechanical stimulation of the anterior part of the tongue, and f) the reflex evoked by stimulation of other parts of the oral region had a longer latency and less intense discharge. The results obtained at higher stimulation rate show that a) individual bursts of reflex discharge could be traced at stimulation frequencies up to 60 Hz, b) except for a moderate decrease the discharge did not disappear when stimulus frequencies of 5, 30 and 50 Hz were used.
Metabolism of Fracture Callus of Rat in vitro: II. Incorporation of 35S‐Sulphate, 3H‐Proline and 32P‐Phosphate
Authors: Penttinen R.
Published: December 2008

The incorporation rate of 35S‐sulphate into the glycosaminoglycans of callus in vitro was at the highest on the 7th day after the fracture corresponding with the proliferation of cartilage. Protein synthesis per callus occurred at the maximal rate 4 days later (during the transition of cartilaginous to ossifying callus) as judged from the radioactivities of 3H‐hydroxyproline and 3H‐proline in collagen and other proteins.

Radioactive phosphate accumulated maximally into the cartilaginous matrix on the 7th day and into the osseous matrix on the 21st day after the fracture. No differences in activities were detected between heated and intact slices indicating non‐enzymatic uptake of phosphate ions from the medium.
Storage Properties of Rat Mast Cell Granules In vitro
Authors: Bergendorff Anders , Uvnäs Börje
Published: December 2008

Basophil granules were isolated from rat peritoneal and thoracic mast cells. The granules were depleted of their endogenous Hi and 5‐HT. The uptake of Hi, 5‐HT, TrpA, PhEA, TA, DA, NA, ACh, Na and Ca (for abbreviations see page 215) by the depleted granules, the release of Hi from Hi‐recharged granules by Ca, Na and K and the competition between NA and Hi, ACh and NA, ACh and Hi for the granule storage sites were studied. The results support the hypothesis that these granule stores have the properties of a weak cation exchange resin. Furthermore it was found that amphetamine and ephedrine competed with NA for the storage sites The results indicate an unspecific granule storage of cations—organic and inorganic—differing only in their affinities for the binding sites.
Increased Synthesis of Prostaglandins in the Guinea Pig Following Scalding Injury
Authors: Hamberg Mats , Jonsson Carl‐Evert
Published: December 2008

The urinary excretion in guinea pigs of the major urinary metabolite of prostaglandins E1 and E2, viz 5β,7α‐dihydroxy‐11‐ketotetranor‐prostanoic acid, was increased 5–9 fold following scalding injury. Lipid extracts of homogenates of scalded guinea pig skin contained 20–40 times more smooth muscle stimulating activity than did extracts of non‐scalded skin. Prostaglandins (mainly PGE2 and PGF2α) were responsible for about 80% of this activity.
Intestinal Vasodilatation in Response to Transmural Electrical Field Stimulation
Authors: Biber Björn , Fara John , Lundgren Ove
Published: December 2008

Electrical field stimulation of the small intestine in vivo in cats induces a 60–150% increase in total intestinal blood flow. The vasodilatory response to field stimulation is blocked by tetrodotoxin and lidocaine, but is unaffected by extrinsic denervation of the intestine, by cholinergic and adrenergic pharmacological blocking agents, and also by cross perfusion of the stimulated intestine from a donor animal. The participation of a local nervous structure in the control of intestinal blood flow is suggested.