摘要:

Electronmicroscopical studies of the rat ileum have demonstrated the presence of submucosal neuronlike cells located just under the basal lamina of intestinal crypts. These cells had dendrite‐like processes and frequently made contacts with adjacent submucosal nerve terminals. Furthermore, within the mucosa epithelial ‘clear’ cells with apical cytoplasmic processes into the gut lumen and basal cytoplasmic processes extending underneath adjacent epithelial cells were demonstrated. The ‘clear’ cells were devoid of secretory granules, as e.g. endocrine cells. and had a morphological resembiance to taste cells. Occasionally the ‘clear’ cells made contacts with submucosal nerve tcrminals. The possibility that the ‘clear’ cells and submucosal neuronlike cells represent a receptive function within the intes

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1982.tb06967.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The effect of head‐up tilt upon subcutaneous and skeletal muscle blood flow in the crus was studied before and during epidural blockade in 10 subjects. Relative changes in blood flow were estimated by the local133Xe washout technique. In subcutaneous tissue head‐up tilt induced a decrease in blood flow of about 40% and there was no difference in the vascular response to head‐up tilt before and during epidural blockade. In skeletal muscle tissue essentially the same was found as head‐up tilt decreased blood flow by about 26% the response being uninfluenced by epidural blockade. In 3 patients local nervous blockade was induced by Lidocaine in133Xe labelled subcutaneous tissue on one side. During epidural blockade and tilt blood flow increased by 12% whereas blood flow decreased by 30% on the control side. Thus epidural blockade had no influence on the vasoconstrictor response in subcutaneous tissue and skeletal muscle to head‐up tilt whereas local blockade was able to prevent the response. Local mechanisms including the local veno‐arteriolar reflex appear to play an important role for the observed maintenance of arterial blood pressure in the tilted position during central sympathet

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1982.tb06968.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

In order to study how the diet may influence sympatho‐adrenal activity during exercise, 7 subjects were examined at rest and during submaximal exercise (25 min at 65 % of °O2max) on two occasions. The first occasion was preceded by 5 days on a carbohydrate poor diet (5% carbohydrate, 72% fat and 23% protein) and the second one by 5 days on a carbohydrate rich diet (78 % carbohydrate, 8 % fat and 14% protein) with the same energy content. Oxygen uptake, respiratory exchange ratio (R), heart rate and arterial plasma concentrations of adrenaline, noradrenaline, dopamine, insulin, glucose, lactate, free fatty acids (FFA), glycerol and β‐hydroxybutyrate were measured at rest and during exercise. Oxygen uptake and heart rate during exercise were higher and R was lower after the carbohydrate poor than after the carbohydrate rich diet. During exercise the arterial plasma concentrations of FFA, glycerol and β‐hydroxybutyrate were higher after the carbohydrate poor than after the carbohydrate rich diet whereas concentrations of insulin and lactate were lower. At rest arterial plasma noradrenaline and adrenaline levels were similar on the two diets (0.70±0.31 nM noradrenaline and 0.35±0.32 nM adrenaline on the carbohydrate rich diet, mean values ± SD). Exercise induced increases in noradrenaline were more pronounced after the carbohydrate poor than after the carbohydrate rich diet (12.42±3.41 vs. 7.45±2.68 at 25 min of exercise,p<0.001). A similar, although more variable accentuation of exercise induced increases in adrenaline was found. It is concluded that, when compared to a carbohydrate rich diet, a carobohydrate poor diet increases the relative contribution of fat to oxidative metabolism and increases the sympatho‐adrenal response to exercise. Stimulation of lipolysis by sympatho‐adrenal mechanisms might be of importance for the substrate availability when carbohydr

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1982.tb06969.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The time course of the latency relaxation was studied at various temperatures in the range 0–26°C. Over the entire range the time of onset of the drop in tension, t1, was independent of sarcomere length. At temperatures above 12–15°C the falling phase had a point of inflexion, while at lower temperatures there was an interval during which the tension fell at a constante rate. The time when the rate of drop in tension had passed its maximum value t1,2, the time to the maximurn drop in tension t2, and the time when the tension crossed the resting level t3, all showed linear dependence on sarcomere length in the range from 2.1 to 2.7–3.4 μm. In this range the durations of the intervals t1.2‐t1, t2‐t1, and t3‐t1were nearly proportional to the distance from the Z‐line to the end of the zone of overlap between the thick and the thin filaments. This could be explained as the activation being a longitudinal process starting from the Z‐line. The slopes (dt/dS) of the linear portions of the time variables t1,2, t2, and t3in a time‐sarcomere length (S) diagram all had the same dependence on temperature giving a Q10of 1.75. Under the assumption that the activation process followed a diffusion of calcium from the Z‐line region to the zone of overlap a diffusion coefficient was estimated. At room temperature it had a magnitude of about 1/20 of that for calcium chloride in water. It had a dependence on temperature corresponding to an Arrhenius activation energy of about 37 kJ/mol which is about twice the activation energy for a simple diffusion of calcium in water. The results can be interpreted in terms of the time course of the latency relaxation mainly reflecting a longitudinal diffusion of calcium

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1982.tb06970.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The time from stimulation to the first change of the extensibility in an isolated skeletal muscle fibre was measured by subjecting the fibre to a rapid, small stretch at various times during the latent period. The experiments were performed at constant temperatures in the range 1–16°C. Irrespective of the temperature, the first increase of the resistance to stretch occurred after the onset of the latency relaxation. At a temperature of 10°C and a sarcomere length of 3 μm the resistance started to increase 5.5 ms after stimulation, i.e. 1.5–2 ms after the onset of the drop in tension, and then increased nearly linearly with time. Corresponding to the end of the latent period, i.e. when the tension recrosses the resting level, the amplitude of the response was about 1.5 times its resting value. There was an interval between the onset of increase of the resistance to stretch and the time when the rate of drop in tension had passed its maximum value. The results are compatible with the hypothesis that the latency relaxation arises from a minute lengthening of the thin filaments as proposed by Haugen&Sten‐Knudsen, and that attachment and generation of force take place at separate steps of the cross‐br

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1982.tb06971.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Renal function, plasma renin concentration (PRC) and prostaglandin (PG) excretion rate was studied in groups of Sprdgue‐Dawley (SPRD) and Wistar (WIST) rats anesthetized with either Halothane‐N2O or Inactin. Conscious rats were used as controls. A. In Halothane‐N2O anesthesia inulin clearance (CIN) and absolute proximal reabsorption rate (APR) was moderately decreased (by about 20%). while renal plasma flow (RPF), urine flow and solute excretion remained unchanged as compared to conscious rats. There was a linear relationship between the reciprocal of the proximal occlusion time (OT) and CINin Halothane anesthesia indicating that the proximal luminal diameter was constant and independent of CIN. B. In Inactin anesthesia CINwas similarly reduced but APR was more depressed (by about 35%). RPF and solute excretion rate decreased only in SPRD rats, while urine flow was significantly reduced in both strains. l/OT was invariant to changes in CINindicating luminal diameter variations in proportion to CIN. Urinary PGE2‐and PGF2αexcretion rates and PRC were moderately elevated in operated animals of both strains regardless of the anesthetics used. It is concluded that renal functional parameters in surgically prepared rats are more severely depressed by Inactin than by Halothane‐N2O anesthesia. The gas anesthesia is equally well tolerated by both strai

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1982.tb06972.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The aim was to study differences in filtration driving forces and glomerular filtration rates between superficial and deep nephrons when urine flow rate was altered at the macula densa region. In young rats stop‐flow pressures and single nephron glomerular filtration rates (SNGFR) were measured in the superficial proximal tubules and in the loops of Henle in the papilla. SNGFR was also measured with a modified Hanssen technique. The stop‐flow pressures of superficial nephrons amounted to 30.9±0.8 mmHg (mean ± SE) and those of juxtamedullary nephrons to 52.2±1.6 mmHg. In the stop‐flow condition the net driving filtration forces were calculated to be about 19 mmHg and 50 mmHg for the superficial and deep glomeruli, respectively. In free flow conditions both net driving forces were calculated to be 19 mmHg. The micropuncture technique gave a SNGFR value for superficial nephrons of 29.6±2.9 and for deep nephrons of 84.1±8.5 nl±min‐1g‐1kidney weight (KW). With a modified Hanssen technique the corresponding values were 25.8±3.3 and 27.7±2.9 nl. min‐1.g‐1KW. The tubuloglomerular feedback mechanism is considered to have a powerful regulatory influence on the glomerular filtration

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1982.tb06973.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The effects of unilateral stimulation of the cervical sympathetic chain on cerebral and ocular blood flow was investigated in 8 rabbits anesthetized with pentobarbital sodium and pretreated with indomethacin in order to inhibit the formation of prostaglandins. Blood flow determinations were made with the labelled microsphere method during normotension and acute arterial hypertension. Hypertension was induced by ligation of the thoracic aorta. Evans blue was given as a tracer for protein leakage during hypertension. Sympathetic stimulation had no significant effect on the blood flow in the brain under the two conditions studied. In the uvea marked effects of sympathetic stimulation were obtained at normotension as well as at hypertension. There were no indications of breakdown of the blood‐brain barrier or the blood‐aqueous barrier. Thus, there was no evidence for any prostaglandin‐mediated inhibition of sympathetic effects in the brain or th

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1982.tb06974.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The effect of unilateral, electrical stimulatio of the cervical sympathetic chain in rabbits anesthetized with pentobarbital sodium and vasodilated by hypercapnia, acetazolamide, papaverine or PGI2was investigated to determine to what extent the sympathetic nerves to the brain and the eye cause vasoconstriction and prevent overperfusion in previously vasodilated animals. Evans blue was given as a tracer for protein leakage. Blood flow determinations were made with the labelled microsphere method during normotension and acute arterial hypertension. Hypertension was induced by ligation of the thoracic aorta and in some animals metaraminol or angiotensin was also used. Acetazolamide caused a two to threefold increase in cerebral blood flow (CBF) and hypercapnia resulted in a fivefold increase. CBF was not markedly affected by papaverine or PGI2. In the choroid plexus, the ciliary body and choroid, papaverine and hypercapnia caused significant blood flow increases on the control side. Sympathetic stimulation induced a 12 % blood flow reduction in the brain in normotensive, hypercapnic animals. Marked effects of sympathetic stimulation at normotension were obtained under all conditions in the eye. In the hypertensive state the CBF reduction during sympathetic stimulation was moderate, but highly significant in hypercapnic or papaverine‐treated animals as well as in controls. Leakage of Evans blue was more frequently seen on the nonstimulated side of the brain. In the eye there was leakage only on the control side except in PGI2‐treated animals where 2 rabbits had bilateral leakage.The effect of sympathetic stimulation on the blood flow in the cerebrum and cerebellum in vasodilated animals seems to be small or absent if the blood pressure is normal. In the eye pronounced vasoconstriction occurs under these conditions. In acute arterial hypertension sympathetic stimulation protects both the cerebral and ocular barriers even under conditions of marked vasodilat

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1982.tb06975.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

The formation of cadaverine and putrescine was studied in the kidneys of gonadectomized male mice stimulated to growth by nandrolone. an anbolic steroid with low androgenic activity. Administration of nandrolone resulted in an increased kidney weight and elevated activities of lysine and ornithine decarboxylase (assayed by measurement of the formation of14CO2from the I‐14C‐labelled amino acids). The responses were dose and time dependent. The elevated enzyme activities were reflected by an increased endogenous kidney content of cadaverine and putrescine as well as in an increased urinary excretion of the diamines. Further, the kidney content and the urinary excretion of the polyamines sper‐midine and spermine were elevated on nandrolone treatment. Fractionation of kidney extracts on pore gradient electrophoresis revealed an apparent molecular weight of about 95000 Daltons of the lysine decarboxylase as well as of the ornithine decarboxylase. On electrofocusing it was evident that both enzymes were present as more than one isoelectric form. However, the main form in both cases focused at a pH of abou

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1982.tb06976.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY