摘要:

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 fib

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb03967.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractAreskog, N.‐H., G. Arturson and G. Grotte. Studies on heart lymph. I. Kinetics of131I‐albumin in dog heart‐lung Preparations. Acta physiol. scand. 1964. 62.209–217. — The transport of131I‐albumin from plasma to lymph was studied in dog heart‐lung preparations. Cannulation of a lymph vessel mainly draining the left ventricle was performed. After injection of the labelled substance, plasma mixing was complete within a few minutes. The plasma concentration of the tracer was constant for 2–3 hours. During this time plasma and heart‐lymph samples were collected. The increase in the concentration of the labelled substance in heart‐lymph showed a time course indicating that the substance from the intra‐vascular compartment was mainly distributed to a single extra‐vascular compartment. The data could thus be fully explained by a two‐compartment model and the permeability constants and the size of the extra‐vascular albumin space drained by the lymphatic canola could be calculated.The present experimental approach therefore allowed a “quantitative lymph experiment”, i. e. the size of the extra‐vascular albumin space drained by a lymphatic cannula could be defined and also an idea of the amount of albumin filtered across the capillary walls and the rate of removal of albumin from the extra‐vascular sp

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb03968.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractAreskog, N.‐H., G. Arturson, G. Grotte and G. Wallenius.Studies on heart lymph. II. Capillary permeability of the dog's heart, using Dextran as a test substance. Acta physiol. scand. 1964.62. 218–223.— The capillary permeability of the normal heart has been studied in ten dogs, using dextran as a test substance. The capillary permeability has been determined as the ratio of the concentration of dextran of various molecular weights present in lymph and plasma under “steady state conditions”. The results show a pattern similar to those of earlier investigations, where lymph from the leg and the cervical region was collected, i.e., capillary pores (pore radii 40–60 Å) and capillary “leaks” (120–300 Å), the only difference being an increased number of “leaks” in the heart capillaries compared wit

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb03969.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractGöransson, G. and T. Olivecrona.The metabolism of fatty acids in the rat. I. Palmitic acid. Acta physiol. scand. 1964.62. 224–239. — Data on the concentration and the fatty acid composition of neutral lipid fatty acids and of phospholipid fatty acids in blood, liver, heart, kidney, lung, spleen and muscle from fasted and refed male rats are reported. Data are also given on the radioactivity in these tissue lipid fractions at several time intervals after the intrevenous injection of 9–10‐H3‐labeled palmitic acid in rat serum. These data are intended as a reference for further studies on the metabolism of other long‐chain fatty acids. The data are discussed with reference to a general picture of the metabolism of the plasma FFA after their removal from the plasma. After entering the tissues the FFA are oxidized, converted to other long‐chain fatty acids, esterified or transferred back to the plasma. The fractions diverted into the different pathways depend upon the nutritional state. The fraction oxidized is larger in the fasted than in the refed rats. The diversion into one or the other of the possible pathways occurs almost immediately after the FFA have entered the tissue. Subsequently, the remaining labeled fatty acids are metabolized at considerably lower fractional rates since they have entered larger fatty acid pools, than the p

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb03970.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractEkelund, L. G. and A. Holmgren.Circulatory and respiratory adaptation during lone‐term, non‐steady state exercise in the sitting position. Acta physiol. scand. 1964.62. 240–255. — Circulatory and respiratory changes during long‐term, non‐steady state exercise in the sitting position was studied with heart catheterization technique in six healthy young men with average training. The work load was chosen individually to increase the heart rate to about 140–150 beats per minute after 10 min work and to 170–180 beats per min after 60 min work.The circulatory changesduring these experimental conditions were characterized by continuously falling systemic arterial blood pressure, constant cardiac output, and increasing heart rate, indicating a continuously fallinn stroke volume. The blood volume was lower during exercise than at rest in the supine position but remained unchanged between 10 and 50 min work. Theacid‐basestatus was characterized as a compensated metabolic acidosis, which remained essentially constant throughout the test. Therespiratory responsewas characterized by a successively increasing total ventilation, a moderate increase in alveolar ventilation and a marked increase in dead‐space ventilation. The increase in total ventilation was effectuated by an increase of both the respiratory rate and the tidal volume. The overallventilation‐perfusion relationshipshowed a slight continuous increase. Both circulatory and respiratory changes may be explained in the light of a gravitational shift in the distributio

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb03971.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractMartinson, J.The effect of graded stimulation of efferent vagal nerve fibres on gastric motility. Acta physiol. scand. 1964.62. 256–262. — The gastric motor responses to efferent vagal stimulation of varying frequency and impulse duration were studied in cats. The efferent fibres, both excitatory and inhibitory, exert their maximum effect on stimulation by an impulse rate of about 10 imp/sec. Higher frequencies producing little, if any, further effect. The stimulation thresholds of the excitatory and inhibitory fibres depend only on the strength and duration of stimulation pulses and not on their frequency, so that high frequency‐stimulation is not equivalent to high‐intensity stimulation,i. e. stimulation with long‐duration pulses, regarding its ability to produce gastric motor inhibition. The findings argue against the inhibition observed being produced by overflowing transmitter substance from aberrant sympathetic vasomotor nerve fibres running in the vagal supply to th

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb03972.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractJohansson, B., E. Linder and T. Seeman.Collateral blood flow in the myocardium of dogs measured with Krypton85. Acta physiol. scand. 1964.62. 263–270. — Methods have recently been developed for determination of regional blood flows from wash‐out curves recorded externally after close‐arterial injection of radioactive Krypton (Kr85). In the present study this technique has been applied to measurement of collateral capillary blood flow in the myocardium of dogs during acute occlusions of coronary arteries. A monoexponential fall in activity was found during elimination of Krypton from the normal myocardium indicating a homogeneous distribution of blood flow. The wash‐out curves recorded during coronary occlusions could be dissolved into two separate components. There was a rapid phase related to the elimination of Krypton from normally perfused regions of the myocardium and a slow phase due to the de‐saturation of the ischemic portion. The magnitude of the collateral capillary blood flow was determined from the decay rate of the slow component. The relative size of the ischemic region could be estimated from the zero time values of the two phases. Collateral blood flow seemed to be fairly homogeneously distributed within the ischemic part of the myocardium. Release of an occlusion was followed by a rapid fall in activity in association with the reactiv

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb03973.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractLaurell, C.‐B. and E. Morgan.Iron exchange between transferrin and the placenta in the rat. Acta physiol. scand. 1964.62. 271–279. — The process of iron exchange between transferrin and the placenta was studiedin vitrousing59Fe, rat serum or purified rat transferrin labelled with131I and placental tissue. The yolk sac placenta bound more transferrin and took up iron more rapidly than did the allantoic placenta. The amount of transferrin bound increased rapidly for the first 15 minutes but thereafter showed little further increase: the amount bound increased as the transferrin concentration was increased but was unaffected by the degree of its saturation with iron. Iron uptake increased steadily during incubation, was greater when the iron concentration was increased, but was unaffected by increasing the transferrin concentration with a constant iron concentration. The release of iron from placenta was slower than that of transferrin and was less into a transferrin‐free solution than into plasma. The intravenous injection of rat transferrin in amounts sufficient to approximately double the plasma concentration did not alter the subsequent transfer of59Fe from maternal plasma to the fetuses. The results show that the mechanism of iron exchange between transferrin and rat placenta is very similar to that between transferrin and reticu

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb03974.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractJohansson, B., O. Lundgren and S. Mellander.Reflex influence of “somatic pressor and depressor afferents” on resistance and capacitance vessels and on Tran capillary fluid exchange. Acta physiol. scand. 1964.62. 280–286. — The reflex circulatory effects of afferent somatic nerve stimulation were studied in the different consecutive vascular sections in skeletal muscle and intestine. In skeletal muscle the “somatic pressor reflex” elicited constriction of resistance and capacitance vessels and increased the pre‐/postcapillary resistance ratio while precapillary sphincter tone was unchanged. In the intestine there was reflex constriction of capacitance and precapillary sphincter vessels but only transient changes in the resistance function. In a situation of increased vasoconstrictor fiber activity produced by carotid occlusion stimulation of “somatic depressor afferents” elicited dilatation of resistance and capacitance vessels in both skeletal muscle and intestine. Carotid occlusion produced continuous absorption of fluid from the extravascular space in skeletal muscle due to a fall in capillary pressure. A superimposed stimulation of somatic depressor afferents was able to restore capillary pressure to the control level despite incomplete restoration of total resistance and capacitance functions. A dilatation of precapillary sphincters occurred in intestine but apparently not in skeletal muscle during the somatic

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb03975.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

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 lin

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb03976.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY