ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1981.tb02042.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Abstract.The mechanism of renal vasoconstriction produced by saralasin and its dependence on the sympathetic nervous system was investigated in subjects with mild essential hypertension and in anaesthetized dogs. Fluid or saline was given to maximize agonist vasoconstrictor responses. The changes in renal hae‐modynamics produced by intravenously infused saralasin (doses 0.01–10 μg kg‐1min‐1) were assessed by clearance methods. In the patients, it induced a dose‐related renal vasoconstriction which correlated with a rise in plasma noradrenaline levels. In dogs with innervated kidneys it also caused vasoconstriction. But in dogs with denervated kidneys it caused vasodilatation. Infusion at the highest dose directly into the renal artery of denervated kidneys induced only vasodilatation. We conclude that one component of the renal vasoconstriction that occurs with intravenous saralasin infusions is mediated by the re

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1981.tb02043.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Abstract.The effect of indomethacin (75 mg/day for 3 days) on the response to i.v. angiotensin II was investigated in eight healthy, sodium‐repleted, male subjects. Indomethacin reduced the release of aldosterone during the i.v. administration of angiotensin II (5, 10 and 20 ng kg‐1min‐1), whereas the pressor response to angiotensin II and to succinamyl1‐val5‐phenylglycine‐acetate8‐angiotensin II, an agonistic angiotensin II‐analogue, was increased. Plasma renin concentration was reduced following treatment with indomethacin. These data confirm the modulatory influence of endogenous prostaglandins upon the vasoconstrictor effect of angiotensin II and could suggest a direct interference of prostaglandins with the secretion

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1981.tb02044.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Abstract.A proliferative, non‐crescentic, glomerulonephritis (GN) was induced in rats preimmunized with rabbit IgG by injecting a sub‐nephrotoxic dose of rabbit anti‐GBM IgG. Control rats either received anti‐GBM IgG only, or were totally irradiated (800 rads, kidneys protected) 2 days before the second injection. All the GN rats developed a severe proteinuria within 2–4 days after the injection of anti‐GBM IgG, contrarily to the control rats. At the same time, many mononuclear cells, of predominantly extra‐renal origin, infiltrated the glomeruli. Glomeruli were isolated from GN, normal and control rats and were cultivated in RPMI medium. In normal and control rat cultures, epithelial and mesangial cells were observed. In GN rat cultures, not only epithelial and mesangial cells, but also endothelial and macrophagic cells were identified; the outgrowth capacity of the mesangial cells was enhanced. These data were particularly evident in cultures of GN glomeruli isolated within 2–4 days after the induction of the renal disease, exactly when the glomeruli were infiltrated by a large number of mononuclear phagocytes. It is suggested that the mononuclear phagocytes infiltrating the glomeruli of rats with this model of GN stimulate the proliferation of endothelial and mesangial

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1981.tb02045.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Abstract.We investigated active and inactive (acid‐activatable) plasma renin in anephric and in normal persons. In anephric patients (n= 15) plasma concentration of active and inactive renin was 1.15 ± 0.2 and 40.7 ± 7.1 μU/ml, respectively; angiotensin II (n= 13) was 14.5 ± 1.9 pg/ml. Furosemide (n= 10), 40 mg i.v., and upright posture (n= 8) did not change active or inactive renin in the anephric state. In normal men, furosemide (n= 9) within 15 min increased active renin from 29.9 ± 5.8 to 82.4 ± 14.8 (μ/ml (Plt; 0.001), while inactive renin slightly but not significantly decreased from 136.3 ± 29.9 to 121.1 ± 19.2 μU/ml; orthostasis (n= 15) within 4 h stimulated active renin (P<0.001) and slightly raised inactive renin (P<005). Both furosemide and orthostasis increased (P<0.001, each) the proportion of active renin in normal persons. Studies in one patient within 24 h after bilateral nephrectomy indicated half‐life to be 30–60 min for active and 2–4 h for inactive renin. Thus, we detected low levels of active renin and considerable amounts of inactive renin and angiotensin II in anephric patients. Our data suggest that about 30%, of inactive renin in normal plasma is of extrarenal origin. The stimulation of active renin by furosemide and orthostasis is bound to the presence of the kidney. Our studies provide indirect evidence that both manoeuvres may stimulate the conversion of inactive to active renin within

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1981.tb02046.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Abstract.In an attempt to characterize the adenylate cyclase‐coupled alpha‐adrenoceptors of human fat cells the effects of various alpha‐adrenergic agonists and antagonists were examined in the presence of 0.05 mmol/1 of propranolol.The order of agonist potencies with respect to alpha‐adrenergic inhibition was (—)‐adrenaline>alpha‐methyl‐(‐)‐noradrenaline » (—)‐phenylephrine with half‐maximal inhibition occurring at 2 μmol/1 of (‐)‐adrenaline and 7 μmol/l of alpha‐methyl‐(‐)‐noradrenaline respectively.The inhibition of adenylate cyclase induced by 005 mmol/1 of (—)‐adrenaline was reversed by the alpha‐blocking agents yohimbine and prazosin, with the alphai‐site‐directed antagonist yohimbine being more than 100‐times more potent than prazosin which is more active at alphai‐sites.The results show that the cyclase‐coupled alpha‐adrenoceptors of human fat cells, which probably represent the physiologically relevant target of antili‐polytic catecholamine effects, displa

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1981.tb02047.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Abstract.The effects of human growth hormone (GH) on glucose homeostasis and the secretion of insulin and glucagon was investigated in eighteen healthy subjects. GH (40 μg/kg) was given as a 30 min i.v. infusion and was followed immediately, or after 60 min, by either a glucose infusion, or an i.v. L‐arginine infusion or i.v. insulin (005 IU/kg).An insulin‐like effect of GH was seen about 15 min after the start of the GH infusion, and became a diabetogenic action 90 min later. Basal and glucose stimulated insulin secretion were suppressed 60 min after the start of the GH infusion, while insulin response to i.v. L‐arginine, on the whole, was uninfluenced. Basal glucagon as well as glucagon response to arginine or hypoglycaemia were uninfluenced by GH. GH did not alter the degree of hypoglycaemia reached after i.v. insulin, whereas the rapidity of blood glucose fall was significantly decreased. The restitution of blood glucose after its nadir was not modified by the hormone.These results demonstrate that the diabetogenic action of GH is not mediated by GH effects on glucagon secretion, and that GH is of little importance in the acute counter‐regulation of insulin‐induced hyp

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1981.tb02048.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Abstract.Experimental diabetes is associated with decreased pancreatic amylase activity resulting from reduced amylase synthesis and increased amounts of trypsinogen and chymotrypsinogen. The effects of different diets and of experimental diabetes on the synthesis of chymotrypsinogen and trypsinogen in rat pancreas were studied by measuring the incorporation of [4,5‐3H]leucine into these proteins by specific im‐munoprecipitation and simultaneous determination of the specific radioactivity of the pancreatic leucine pool. In addition the effect of acute glucagon treatment on the synthesis of these enzymes was examined. In rat pancreas two trypsinogens and one chymotrypsinogen were found. There was no precursor‐product relationship between the two trypsinogens. Changes in the rate of synthesis affected both isoenzymes to the same extent. Starvation was associated with a decreased rate of synthesis of total pancreatic protein, chymotrypsinogen and trypsinogen. A protein‐rich diet led to an increased rate of synthesis of chymotrypsinogen and trypsinogen, but not of total protein. A carbohydrate‐rich diet diminished the amounts of pancreatic chymotrypsinogen and trypsinogen and the rates of synthesis of these enzymes, whereas a fat‐rich diet had no significant effects on these parameters.Diabetes was associated with increased amounts of chymotrypsinogen and trypsinogen in the pancreas. This resulted from a dramatic increase in their rates of synthesis, whereas that of total pancreatic protein showed no significant change. The same pattern was observed in diabetic adrenalectomized rats or diabetic rats receiving the same amount of a standard diet as non‐diabetic controls. Treatment of rats with glucagon for 6 or 12 h led to a marked decrease of the amounts of pancreatic zymogens, whereas the rates of synthesis of chymotrypsinogen and trypsinogen were only slight

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1981.tb02049.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Abstract.Metabolic turnover of fibrinogen and plasminogen were studied in thirty insulin‐treated diabetics and ten non‐diabetic controls. 131‐iodine labelled fibrinogen and 125‐iodine labelled plasminogen were injected intravenously and the plasma clearance of the two proteins measured simultaneously over a period of 8 days. The diabetics were selected to represent three grades of severity of diabetic retinopathy assessed by ophthalmoscopy and fiuorescein angiography; ten patients had no significant retinopathy, ten background and ten proliferative retinopathy. Subjects were matched as closely as possible for body weight, age and duration of diabetes.Plasma fibrinogen concentrations were higher in diabetics (3–24 g/1) than controls (2–65 g/1;P<0.025); the patients with the severest retinopathy had the highest fibrinogen concentrations (3.75 g/1). As a direct consequence of the elevation of plasma fibrinogen the catabolic rate was higher in diabetics (20.9 mg kg‐1day‐1) than controls (140 mg kg‐1day‐1;P<0.025) and higher in patients with background retinopathy (24.1 mg kg‐1day‐1) and proliferative retinopathy (22.4 mg kg‐1day‐1) than diabetics without retinopathy (16.3 mg kg‐1day‐1;P= 0.05). Fibrin(ogen) degradation products were detectable in all diabetics but in only one‐third of controls.Plasminogen metabolism was normal in all groups of diabetics.It is concluded that fibrinogen metabolism is increased in diabetes and bears a relationship to diabetic retinopathy but is not accompanied by significant alte

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1981.tb02050.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Abstract.An in vitro technique was devised to test the effects on protein synthesis of plasma dialysate from control and uraemic subjects. Each plasma was dia‐lysed for 24 h to extract the molecules having molecular weight less than 12,000 and the dialysate was lyophilized. Protein synthesis was studied in vitro, using a cell‐free system form mouse Krebs II ascites cells. The cells were lysed, and the 30,000 g supernatant (‘S‐30 lysate’) was used to test the protein‐synthesizing activity of dialysates of control and uraemic plasma. The rate of protein synthesis was monitored by measuring the incorporation of [14C]leucine into tri‐chloracetic acid‐precipitable material in the presence of various amounts of plasma dialysate.The presence of normal plasma dialysate increased the [14C]leucine incorporation rate which went through a maximum for 20–22 μl of added plasma dialysate. In contrast, in the presence of uraemic plasma dialysate, the incorporation rate of the radiolabel decreased as the amount of uraemic dialysate was raised. The ratio of incorporation in the presence of these two kinds of plasma dialysates significantly differed (P<001) in the range of 15–25 μl of added plasma dialysate. Heating the uraemic plasma dialysate at 100 C for 1 h prior to incubation almost restored the ratio of [14C]leucine incorporation to control values.Therefore it is concluded that: (1) uraemic plasma inhibits protein synthesis, (2) a significant part of this inhibitory effect is related to thermosensitive molecules, (3) the total inhibition appears to be the results of combined effects of ionic and organic compounds accumula

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1981.tb02051.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY