bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Hypothalamic Lesions on the Erythropoietic Response to Hypoxia in Rabbits1
Authors: Halvorsen Sverre 
Published: December 2008

AbstractPrevious studies have indicated that electrical stimulation of the hypothalamus increases erythropoiesis (Seip et al. 1961) and erythropoietin production (Halvorsen 1961). The effects of hypothalamic lesions on the erythropoietic response to hypoxia have been investigated in the present study. The lesioned rabbits were exposed to low oxygen and the erythropoietic response evaluated by means of reticulocyte counts. Eleven out of 26 rabbits showed a normal response to hypoxia while 15 showed a reduced response. Of these 15 rabbits, 6 showed a normal response when ACTH was given prior to the hypoxic test indicating that the reduced response to hypoxia in these rabbits was due to ACTH deficiency following the hypothalamic lesion. The lesions in these 6 rabbits were in the ventral and median part of hypothalamus. Seven out of the 15 rabbits neither responded normally to hypoxia alone nor to hypoxia following ACTH injections. The lesions in these 7 rabbits were in the posterior part of the hypothalamus. It is concluded that an extra‐pituitary influence on erythropoiesis may be exerted from this region.
Palmitate Utilization in Obese‐Hyperglycemic Mice In vitro studies of epididymal adipose tissue and liver
Authors: Hellman Bo , Westman Sighild 
Published: December 2008

AbstractThe in vitro utilization of 14C1‐palmitate was studied in epididymal adipose tissue and liver slices from obese‐hyperglycemic mice and their lean littermates. Starvation and/or addition of glucose to the incubation medium had less effect on the palmitate metabolism of the epididymal fat pad in the obese mice than in the lean controls. The presence of glucose thus resulted in a significantly lower recovery of radioactive carbon dioxide and tissue fatty acids in the controls; no such effect being noted in the obese mice. In both types of mice starvation decreased the incorporation of palmitate carbon in the lipid fraction of adipose tissue incubated in a glucose‐containing medium. Fatty acid release from the isolated epididymal fat pad was also less affected in the obese mice than in the lean littermates by starvation and addition of glucose. The incorporation of the substrate palmitate into hepatic tissue lipids did not differ significantly between the two types of mice, when tested in the presence of glucose. In this case starvation resulted in reduced amounts of radioactivity in carbon dioxide and insoluble residue only for the liver slices taken from the lean mice. The results are discussed with regard to previous metabolic findings in the obese‐hyperglycemic syndrome.
The Measurement of Input Impedance and Apparent Phase Velocity in the Human Aorta
Authors: Gabe I. T. , Karnell J. , Porjé I. G. , Rudewald B. 
Published: December 2008

AbstractMeasurement of the input impedance in the aorta in 3 patients with rheumatic mitral disease is described. The aortic flow was measured by recording the pressure gradient along the ascending aorta with a differential manometer through a double‐lumen catheter; a separate strain gauge on one side of the system enabled the arterial pressure to be recorded simultaneously. Records were made before and during the administration of i.v. nor‐adrenaline. Computation of blood flow, apparent phase velocity and impedance was performed on a digital computer. The moduli of aortic input impedance decreased with frequency over the first few harmonics both before and during nor‐adrenaline but were higher during infusion. The pattern of impedances tended to suggest that some reflection was reaching the ascending aorta; this was also suggested by the high values obtained for apparent phase velocity at low frequencies.
The Excitation of Thalamic Neurones by Acetylcholine
Authors: Andersen P. , Curtis D. R. 
Published: December 2008

AbstractElectrophoretically administered acetylcholine (ACh) excited neurones located within the ventro‐basal thalamic complex of cats anesthetised with pentobarbital. All ACh sensitive neurones were fired synaptically by volleys in cutaneous nerve fibres; thalamic relay neurones which were fired antidromically from the primary sensory cortex were more sensitive than thalamic interneurones. In comparison with Renshaw cells the excitatory action of ACh was of slow onset and prolonged duration; the spontaneous spindle activity of some cells was depressed prior to excitation. Possible explanations of these time differences between the excitant of ACh upon thalamic and Renshaw cells are discussed.
The Pharmacology of the Synaptic and Acetylcholine‐Induced Excitation of Ventrobasal Thalamic Neurones
Authors: Andersen P. , Curtis D. R. 
Published: December 2008

AbstractThe pharmacological properties of acetylcholine (ACh) sensitive neurones in the ventrobasal nucleus of the thalamus of cats anes‐thetised with pentobarbital sodium have been investigated by the electro‐phoretic method of ejecting substances from multibarrelled micropipettes. Carbamoylcholine, acetyl‐β‐methyl choline, dl‐muscarine and nicotine were effective excitants when compared with ACh; other choline esters and related compounds were less active. Physostigmine and neostigmine increased the effectiveness of ACh and, in addition, were excitants. The excitatory action of ACh was effectively abolished by dihydro‐β‐erythroidine and by atropine; the action of atropine however was not very specific. It is proposed that the sensitivity of these neurones to cholinomimetics indicates that ACh normally functions as an excitatory transmitter within the thalamus; the synaptic pathway involved has not yet been identified. Cholinomimetics, 5‐hydroxy‐tryptamine and some related substances also depress the excitability of thalamic neurones.
Localized Slow Wave Activity in the Somatosensory Cortex of the Cat
Authors: Anderson S. A. , Wolpow E. R. 
Published: December 2008

AbstractDepth recordings with microelectrodes have revealed that transection of the specific projection pathways in the spinal cord induces regular slow waves with a frequency of 8–12 waves per second in the parts of the somatosensory areas SI and SII corresponding to the projection from below the level of the lesion. Surface recordings showed an increased spindle activity in the same areas. The slow wave activity occurs at various depths of Nembutal anesthesia. There is evidence that the appearance of slow waves after interruption of the specific pathways is a general phenomenon in the specific projection cortical areas.
Relation of Preoptic Temperature to the Function of the Sympathico — Adrenomedullary System and the Adrenal Cortex
Authors: Andersson B. , Gale C. C. , Hökfelt B. , Ohga A. 
Published: December 2008

AbstractDuring local cooling of the preoptic/anterior hypothalamic region (the“heat loss center”) at about 18° C external temperature, the urinary excretion of catecholamines was increased. At the same time marked core hyperthermia developed. The relative increase of adrenaline excretion was considerably greater than that of noradrenaline excretion (117 % vs. 48 %). Repetitive central cooling performed over longer periods of time caused signs of cold acclimation in spite of the fact that the animals were not exposed to a lowered external temperature. During local warming of the“heat loss center” in a cold environment (2 to 5° C) the urinary excretion of catecholamines remained low but increased considerably on cessation of central warming. Both adrenaline and noradrenaline excretion then rose to high levels if a more pronounced hypothermia had developed during central warming. With induction of a milder degree of hypothermia the increase was predominantly in noradrenaline excretion. Plasma cortisol determinations did not reveal any clear cut relation between preoptic temperature and adrenocortical activity.
Potentiation of Sham Feeding Response in Pavlov Pouch Dogs by Subthreshold Amounts of Gastrin with and without Acidification of Denervated Antrum
Authors: Olbe Lars 
Published: December 2008

AbstractThe sham feeding response of Pavlov pouch dogs, in which gastrin release had been suppressed by total denervation or resection of the antrum, was augmented 4–21 times by i.v. injection of subthreshold amounts of gastrin demonstrating that subthreshold amounts of gastrin potentiated the effect of vagal stimulation of the HCl glands. The sham feeding responses with or without potentation by subthreshold amounts of exogenous gastrin were not inhibited by acidification of totally denervated antral pouches, suggesting that the hypothetical antral chalone does not interfere at the parietal cell level with the cephalic phase of gastric acid secretion.
Gastric Acid Secretion in Gastric Fistula Cats before and after Vagotomy and in Vagotomized Gastric Fistula Cats during Reserpine Treatment1
Authors: Emås Sverre 
Published: December 2008

AbstractIn nonanesthetized cats with gastric fistulae reserpine ijencted daily for 3 days or more increased basal gastric secretion of acid and the acid secretory responses to intravenous histamine and gastrin. The increases had in an earlier study been shown to persist after symphathectomy and the main purpose of the present study was to determine the effect of vagotomy on these increases. Vagotomy significantly reduced the secretory responses of non‐anesthetized cats to histamine and gastrin and after vagotomy reserpine treatment did not produce any increase of basal secretion or of the secretory responses to histamine and gastrin. The latter finding proves that intact vagal innervation of the stomach is necessary for the development of hypersecretion during reserpine treatment. Maximal subthreshold amounts of methacholine infused intravenously into vagotomized cats produced increases of the secretory responses to histamine and gastrin approximately equal to those produced by reserpine treatment in cats before vagotomy. It is suggested that the reduction of the responses following vagotomy is due mainly to the elimination of the vagal tone which in the fasting cats is assumed to sensitize the parietal cells to histamine and gastrin. The hypersecretory effects of reserpine treatment in cats with gastric fistulae and the absence of these effects after vagotomy demonstrates that reserpine treatment increases the sensitivity of the parietal cells to histamine and gastrin only in the vagally innervated stomach. The increased sensitivity is supposed to be due to a centrally irduced enhancement of vagal tone. The increases in the secretory responses of vagotomized cats during the infusion of subthreshold amounts of methacholine are consistent with this explanation.
Uterine Motility of the Estrogenized Rabbit
Authors: Setekleiv Johannes 
Published: December 2008

AbstractA technique for isotonic and isometric recording of uterine contractions in vivo is described. No significant difference was found in the spontaneous contractions recorded simultaneously from the two horns by the two methods. On the other hand, differences were found in the responses to gradually increasing stimuli, such as increasing concentrations of noradrenaline or of increasing strength of stimulation of the hypogastric nerve. The isotonic response rapidly reached a maximum, whereas the isometric response increased more gradually. Since the isotonic response can be maximal in spite of submaximal activation, the isometric response is a more reliable quantitative measure, which is in agreement with previous findings with in vitro recording. However, for qualitative evaluation of responses near threshold stimulation, isotonic recording at low loads is preferable. Anesthetics administered i.v. in small doses to lightly anesthetized animals slightly enhanced uterine contractions, whereas deep anesthesia and local application of the anesthetics depressed the activity. Uterine motility is extremely sensitive to decrease in body temperature.
Contraction in Intrafusal Muscle Fibres of Xenopus Laevis Following Stimulation of Their Motor Nerves
Authors: Smith Richard S. 
Published: December 2008

AbstractSmith, K. S. Contraction in intramural muscle fibres of Venous leaves following stimulation of their motor nerves. Acta physiol. scand. 1964. 62. 195–208. — The contractile behaviour of amphibian intramural muscle fibres following stimulation of their motor nerves was investigated by cinephotography of the changing sarcomere length. Two types of intrafusal muscle fibre were distinguished: large and small. Small intrafusal muscle fibres were supplied by small diameter motor nerves and had a longe: lasting contraction than the large intrafusal fibres which were supplied by large diameter motor nerves. Contraction was a propagated event in both large and small muscle fibres following single nerve stimuli. At high stimulation frequencies the contraction was not propagated through the complete length of the large muscle fibres. Evidence was obtained that the large muscle fibres contained, in the region of sensory contacts, zones which were less stiff than the resting striated muscle fibre and that the small muscle fibres did not contain such zones. Some observations were also made on spontaneous contraction in these muscle fibres.
The Influence of Chemically Pure Secretin on Hepatic Bile Output
Authors: Jonson Gunnar , Sundman L. , Thulin L. 
Published: December 2008

AbstractJonson, G., L. Sundman, and L. Thulin. The influnce of chemically pure secretin on hepatic bile output. Acta physiol. scand. 1964. 62. 287–290. — In awake cholecystectomized dogs with a permanent external common duct fistula the bile output increased during infusion of a secretin preparation, containing about 20,000 clin. units per mg of substance (Jorpes and Mutt 1961). At the largest dose, about 43 clin. units per kg b. wt. and hour, it was about 3 times the initial output, and even then it was smaller than the output during digestion of food with bile. The relation between the log of the secretin dose and the bile output was linear.
Uterine Motility of the Estrogenized Rabbit
Authors: Setekleiv Johannes 
Published: December 2008

AbstractThe uterus can be reflexly activated by stimulation of the rectum, various somatic nerves, and the central and peripheral ends of the cut vagus nerve. The initial uterine contraction is followed by a period of reduced rhythmic activity. Similar responses can be elicited by asphyxia and by clamping of the common carotid arteries. All these responses are due to activation of the sympathico‐adrenal system. A transient inhibition of the “spontaneous” rhythmic activity is obtained by electrical stimulation of the depressor nerve. Since it is abolished by sympathetic blocking agents, it is most likely due to a reduction of a sympathetic tonic influence. The results indicate that although the autonomy of the myo‐genic rhythmic uterine activity is strong in the estrogenized rabbit, it can be influenced by various reflexes. It is suggested that the sympathetic nervous system exerts a tonic influence on the uterus in vivo.
The Effect of Partial Clamping of the Renal Artery on Pressures in the Proximal and Distal Tubules and Peritubular Capillaries of the Rat Kidney
Authors: Leyssac Paul P. 
Published: December 2008

AbstractThe purpose of this study was to measure the intratubular and peritubular capillary hydrostatic pressures in acute experiments of partial clamping of the renal artery to such a degree that a significant reduction of the filtration pressure was ascertained. The renal artery of rats weighing about 250 grams were clipped with a 0.20 mm silver clamp, which reduced the urine flow and the glomerular filtration rate to below the range of spontaneous variations and caused occlusion of minor or major parts of the nephron population. Intratubular and peritubular capillary pressures were measured directly by the micropuncture technique. The results demonstrated that proximal intratubular as well as peritubular capillary pressures in partially clamped kidneys were not measurably different from those of normal, control kidneys (12–13 mm Hg), whereas distal intratubular pressures were significantly reduced (from 6.7 mm Hg in normal to 3.9 mm Hg) in clamped kidneys. The results are discussed in relation to previous and recent findings and interpretations. The hypothesis a proposed that the physiological function of the juxtaglomerular apparatus is to serve as a feed‐back mechanism whereby changes being a function of the proximal intratubular pressure via the release of angiotensin adjusts the proximal reabsorption and the intrarenal vascular resistance in such a way that proximal intratubular hydrostatic pressures are maintained.
Presynaptic Depolarization of Cutaneous Afferents by Volleys in Contralateral Muscle Afferents
Authors: Eccles Rosamond M. , Holmqvist Birgitta , Voorhoeve P. E. 
Published: December 2008

AbstractDepolarization of cutaneous nerve terminals by all contralateral muscle volleys has been demonstrated by several procedures; by intracellular recording from the cutaneous fibres; by electrotonic spread to dorsal root filaments so giving the dorsal root potentials (DRP); and by threshold changes in the fibre terminals. Groups II and III muscle afferents depolarized cutaneous fibre terminals on both sides of the spinal cord while the Ib volleys were effective only ipsi‐laterally. The crossed actions of group II and III volleys were weaker than the ipsilateral actions and had a longer latency (10–20 msec) and a later summit (50–80 msec). This depolarization of the central terminals of the cutaneous fibres by afferent volleys from contralateral muscles resulted in a depression of synaptic activity of these cutaneous fibres as evidenced by the flexor reflex, the cutaneous dorsal root potential and the afferent cutaneous tract discharge in the spinal cord.
On the Bile Acid and Neutral Fecal Steroid Excretion in Man and Rabbits Following Cholesterol Feeding Bile Acids and Steroids 150
Authors: Hellström Kjell 
Published: December 2008

AbstractThe effect of cholesterol feeding on bile acid turnover and neutral fecal steroid excretion was studied in rabbits and human subjects. In rabbits the addition of 1% cholesterol to a low fat pellet diet (on the average 700 mg of cholesterol per day) caused a marked increase of the serum cholesterol level but a reduction of the turnover and the fecal elimination of deoxycholic acid. On the subsequent feeding of a semisynthetic cholesterol free diet, the serum cholesterol level decreased in spite of a further reduction of the fecal bile acid excretion. When human subjects received a diet containing egg yolk lipids, which provided 1.4 g cholesterol per day, the serum cholesterol level increased moderately over the control values, but there were no consistent effects on either the biliary bile acid composition or on the turnover of cholic acid. The amount of cholesterol excreted as neutral fecal steroids during the cholesterol feeding period corresponded on the average to 80 and 77% of the amount of cholesterol given to rabbits and human subjects respectively. Cholesterol and the plant sterols β‐sitosterol and methylcholesterol were metabolized into neutral compounds that were the same in rabbit and in human feces. Rabbit feces contained proportionally more 5α‐sterols than human feces.
Mixed Venous CO2 Tension‐Determined by a CO2 Rebreathing Method. Influence of Rebreathing Time
Authors: Lundin G. , Thomson D. 
Published: December 2008

AbstractThe influence of rebreathing time when using a CO2 rebreathing method for graphical determination of the mixed venous CO2 tension was studied. An almost significant difference of 0.6 mm was found between values obtained at rebreathing rates of 30 and 50 breaths per min with rebreathing times of 22 and 13 sec. This should give a difference at rest of about 5 per cent when the cardiac output is calculated, with the higher value when the fast rate is used for the mixed venous CO2 determination. The solubility of CO2 in lung tissue probably doses not cause this difference.
Modernized Scholander Respirometer for Small Aquatic Animals
Authors: Steen J. B. , Iversen O. 
Published: December 2008

AbstractA method is described for measuring oxygen uptake of small aquatic animals using from 0.1 to 20 ml oxygen/hr. The water containing the animal is continuously equilibrated with air in a closed system and respiration is measured as the oxygen necessary to maintain a constant gas volume in the presence of a carbon dioxide absorber.
Fusimotor Activity in the Spinal Cat
Authors: Alnæs E. , Jansen J. K. S. , Rudjord T. 
Published: December 2008

AbstractFusimotor activity has been assessed from the changes in the response of muscle spindle receptors to a linear stretch and release of the muscle at various levels of fusimotor drive. The background fusimotor activity of the spinal cat caused an increased dynamic responsiveness of primary endings of ankle flexor as well as the ankle extensor muscles. Further, dynamic activation of both flexor and extensor primary endings was observed during electrical stimulation of the ipsilateral saphenous and the contralateral lateral popliteal nerve. Definite signs of activity in static fusimotor neurones were not found in spinal preparations. The observations support the hypothesis of an independent control of the static and dynamic properties of primary endings of the muscle spindle. It is suggested that the activity in the dynamic fusimotor system largely is supported by dorsal root inflow, whereas the static fusimotor system mainly depends upon descending suprasegmental activation.
Fusimotor Activity in a Flexor Muscle of the Decerebrate Cat
Authors: Jansen J. K. S. , Rudjord T. 
Published: December 2008

AbstractFusimotor activity has been assessed from changes in the response of muscle spindle receptors. There was very little background fusimotor activity to the anterior tibial muscle in the decerebrate cat. To the ankle extensor muscles of the same preparations, appreciable dynamic as well as static fusimotor effects were observed. During stimulation of various spinal nerves, fusimotor activation was more pronounced to ankle extensor than to the flexor muscle. The flexor fusimotor effects could almost exclusively be ascribed to the static fusimotor system. A release of dynamic fusimotor activity to the flexor muscle occurred after section of the spinal cord in the lower thoracic region. The observations are discussed in terms of independent control of static and dynamic fusimotor systems.
Effect of Insulin on the Isolated Rat Diaphragm in the Presence and in the Absence of Puromycin and Actinomycin D1
Authors: SØVIK ODDMUND 
Published: December 2008

AbstractTo determine if insulin‐induced sugar uptake and glycogen synthesis in isolated muscle tissue are dependent upon RNA or protein synthesis, the effect of puromycin and actinomycin D was studied on these parameters. At a concentration of puromycin which inhibited by 97 % the incorporation of 14C‐protein hydrolysate into proteins, an inhibition of the insulin‐stimulated incorporation of 14C‐glucose into glycogen and of the net glycogen synthesis was observed. This puromycin effect was demonstrated in the cut as well as in the intact diaphragm preparation, and at low as well as high glucose concentrations in the incubation medium. The insulin‐induced glucose uptake and D‐xylose transport was not altered by puromycin. Actinomycin D at a concentration which almost blocked the incorporation of 14C‐orotic acid into RNA had no inhibitory effect on glucose uptake or glycogen synthesis. At a higher concentration of actinomycin D, where incorporation of labelled amino acids into proteins was strongly inhibited, insulin stimulation of glycogen synthesis was almost abolished. The results favour the view that synthesis of messenger‐RNA is not involved in the insulin effect on muscle. The relationship between protein synthesis and insulin‐induced glycogen synthesis is discussed.