摘要:

AbstractAn electronic simulator demonstrating some of the properties of biological transducers is described. It is possible to simulate the “nerve activity” and its relation to “generator potential” and the “adaptation phenomenon” for some different kinds of biologica

ISSN:0001-6772    

DOI:10.1111/j.1365-201X.1968.tb10804.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractAdult anesthetized rats were immersed to the larynx and subjected to underwater blast from two charges of 1 g tetryl each, both set off at a distance of 0.8 m from the target. The ratio: weight of the damaged lung/weight of the normal lung, expressing the degree of the lung hemorrhage, and the lethality (one hour survival) were both larger when the two charges were separated by a time interval of 8–25 μsec as compared to simultaneous detonation. The results indicate that the time integral of the pressure is more important for underwater blast damage than is the peak pressure attain

ISSN:0001-6772    

DOI:10.1111/j.1365-201X.1968.tb10805.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractEhinger, B., G. Gennser, Ch. Owman, H. Perssonand N.‐O. Sjöberg.Histochemical and pharmacological studies on amine mechanisms in the umbilical cord, umbilical vein, and ductus venosus of the human fetus. Acta physiol. scand. 1968.72. 15–24.The responsein vitroof the umbilical vein and the ductus venosus to certain pharmacologically active drugs hls been correlated with the adrenergic and cholinergic innervation of this venous system in human fetuses of 20–24 weeks gestational age. No histochemically demonstrable adrenergic or cholinergic nerves occurred in the umbilical cord. In the intra‐abdominal part of the umbilical vein an increasing amount of adrenergic nerves were present in direction towards the ductus venosus. A distinct accumulation of adrenergic nerves was observed at the origin of the ductus venosus, concomitant with an increased thickness of the smooth muscle wall of the vessel. Few, if any, acetylcholinesterase‐containing fibres could be demonstrated in relation to the umbilical vein or ductus venosus. Noradrenaline, acetylcholine, and 5‐hydroxy‐tryptamine produced a contractile response in the intra‐abdominal portion of the umbilical vein as well as ir the first part of the ductus venosus. The noradrenaline response could be reproduced by tyramine and abolished by phenoxybenzamine, which potentiated the contraction induced by 5‐hydroxytryptamine. Atropine inhibited the effect of acetylcholine, but not that of noradrenaline. The presence of aminergic nerves is not indispensable for the existence of vascular smooth muscle receptors for the amines. The accumulation of adrenergic nerves and smooth muscle cells in the wall at the origin of the ductus venosus supports the theory of an adrenergic sphincler mechani

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1968.tb03821.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractNielsen, B.Thermoregulatory responses to arm work, leg work and intermittent leg work. Acta physiol. scand. 1968.72. 25–32.The increase in esophageal temperature during continuous work on a bicycle ergometer with the arms and with the legs was compared. Also the effect of intermittent leg work (30 sec rest/work intervals) was compared to that of continuous work. At the same rate of metabolic energy production the esophageal temperature in the steady state was about the same independent of the different degree of anaerobicity and the different neuromuscular factors. It is therefore suggested that chemical factors liberated in proportion to the aerobic prosesses is responsible for the temperature setting during work. The sweat rate and the skin circulation expressed as conductance of the peripheral tissues carried in proportion to the total heat production independent of neuromuscular factor

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1968.tb03822.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractAn isolated perfused and ventilated lung preparation from the rat is described. After perfusion for 16–30 min the preparation responded with a reversible increase in pulmonary vascular resistence to short (3–4 min) periods of ventilation hypoxia (gas mixtures containing 2–7% O2). This pressor response to hypoxia reached a maximum 45 to 140 min after start of the perfusion. The response then declined and disappeared, whereas the preparation did still respond well to vasoactive drugs. This vulnerability of the pressor response to hypoxia is in agreement with the findings in isolated lung preparations from other species. In this preparation the disappearance of the response could be shown to be due to changes within the lungs themselves, and not to changes in the perfusate blood. None, or very slight, pressor responses to ventilation hypoxia could be elicited in preparations where platelet‐poor plasma was used as a perfusate. If, however, the formed elements of the blood were added to the plasma perfusate, good responses to ventilation hypoxia appeared, provided that the addition was done during the first hour of pe

ISSN:0001-6772    

DOI:10.1111/j.1365-201X.1968.tb10808.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractThe determination of the location of the horizontal axis in the frontal plane for movements in the sagittal plane between L4 and L5 is based on the observation that the erectores spinae muscles and the rectus abdominis muscles in the upright standing position are acting as antagonists and antigravity muscles. X‐ray pictures were taken in the sagittal plane with the subjects standing a) with slight activity in the erector spinae muscles and b) with slight activity in the rectus abdominis muscles. The location of the line of gravity for the parts of the body above the level of L5 was then determined with the subjects standing in the same positions. These determinations revealed that the activity in the erector spinae muscles ceases and is replaced by activity in the rectus abdominis muscles, when the line of gravity passes a point about 3 cm dorsally to the center of the inter‐vertebrate disc between L4 and L5. Similarly the location of the line of gravity in the frontal plane was determined in relation to L5. The results are discussed in view of previous findi

ISSN:0001-6772    

DOI:10.1111/j.1365-201X.1968.tb10809.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractBoth reserpine and benzquinamide were capable pf impairing thein vitrouptake of C14‐adrenaline by bovine and rabbit adreno‐medullary granules, however, they differed markedly in their relative potency. Thein vivostudies using mice and thein vivo—in vitrostudies employing rabbits indicated that the time course of granular blockade after reserpine and benzquinamide injections also differed. Benzquinamide was shorter‐acting and less potent than was reserpine. Subcellular distribution studies indicated that while both drugs could impair the invivouptake of3H‐α‐methyl noradrenaline, only reserpine administration resulted in both an increase in the amount of3H‐α‐methyl noradrenaline found in the supernatant fraction and an increase in the amount of3H‐α‐methyl normetanephrine recovered from the whole heart. It is concluded that while reserpine and benzquinamide have many qualitatively similar effects on amine uptake and depletion, differences in their actions on the subcellular

ISSN:0001-6772    

DOI:10.1111/j.1365-201X.1968.tb10810.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractMale rats were fed isocaloric diets in which were incorporated 46.4 g unpeeled apple or 2 g pectin per day per rat. Serum cholesterol level of the rats on the apple diet was significantly lower than that of the controls. Serum cholesterol level of the rats on the pectin diet was not altered significantly. The amounts of liver cholesterol were not significantly changed by the apple or pectin diet. Uptake of orally given cholesterol‐4‐C14in the liver unsaponifiable lipid was lower in the pectin fed and apple fed animals compared with that of the contr

ISSN:0001-6772    

DOI:10.1111/j.1365-201X.1968.tb10811.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractMouse brain cortex slices have been incubated with tritium labelled acetylcholine, choline and atropine. The subcellular distribution of radioactivity has then been studied by homogenization of the slices in sucrose and separation of the subcellular particles on a continuous exponential sucrose gradient. It was found that about 30 per cent of the radioactivity in the slices were localized in the fraction containing nerve‐endings and mitochondria. Using differential centrifugation and gradient centrifugation of the crude mitochondrial fraction obtained, it was found that acetylcholine is specifically bound to the nerve‐ending particles. Choline had a subcellular distribution similar to acetylcholine, while atropine was not specifically bound to the nerve‐en

ISSN:0001-6772    

DOI:10.1111/j.1365-201X.1968.tb10812.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractTo investigate the effects of leg exercise, on the overall tolerance to exaggerated gravitational stress, 8 subjects were exposed for 13 min to a threefold increase of the force of gravity in centrifuge experiments (+ 3 Gz) while in the sitting position, both during motionless resting and when exercising at 600 kpm/min on a bicycle ergometer. In all subjects, continuous leg exercise prevented the occurrence of circulatory collapse, which otherwise became imminent in 5 subjects after 5 to 12 min in the resting condition as evidenced by blackout or rapid increase in heart rate. Subjectively, exercise was experienced as less stressful than the resting condition. The improved circulatory stability with exercise was also reflected by uniformity of individual heart rate responses, the group mean value increasing from 152 to 160 beats/min during the 6th to 12th min.

ISSN:0001-6772    

DOI:10.1111/j.1365-201X.1968.tb10813.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY