ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1992.tb01928.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1992.tb01929.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Platelets from diabetic humans and animals are hypersensitive to ADP. The hypersensitivity to ADP of platelets from diabetic rats occurs independently of activation of the arachidonate pathway or release of dense granule contents. During platelet aggregation by ADP, fibrinogen binds to its receptor on platelets. We examined if the hypersensitivity to ADP of platelets from diabetic rats is associated with enhanced early binding of fibrinogen to its receptor on these platelets. Fibrinogen association with platelets from rats with spontaneous or streptozotocin‐induced diabetes was significantly greater 10 s or 1 min after addition of ADP (10μm) than with platelets from their corresponding control rats. Since enhanced fibrinogen association occurred with platelets from insulin‐treated rats with spontaneous diabetes, and from rats with streptozotocin‐induced diabetes that did not receive insulin, the enhanced fibrinogen binding is likely due to the diabetic state rather than to the administration of insulin or the mechanism responsible for the diabetes. Therefore, enhanced early fibrinogen association with platelets from diabetic rats is associated with their hypersensitivity

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1992.tb01930.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Localization and functional effects of vasoactive intestinal polypeptide (VIP) and peptide histidine methionine (PHM), two peptides derived from a common precursor molecule, were investigated in isolated preparations from human penile corpus cavernosum (CC) and circumflex vein (CV). VIP‐ and PHM‐immunoreactivity (IR) was demonstrated in both CC and CV. The concentrations of VIP‐IR and PHM‐IR in CC tissue were 54.4PM15.3, and 42.0 PM7.5 pmol g‐1wet weight respectively with a VIP/PHM ratio of 1.5PM0.4 (meanPMSEM). The corresponding values for CV tissues were 28.0 PM7.7 and 9.6 PM2.6 pmol g‐1wet weight with a VIP/PHM ratio of 3.1PM0.4. CC and CV displayed VIP‐ and PHM‐IR confined to nerve fibres in close relation to bundles of smooth muscle cells and blood vessels in both tissues.In vitro, VIP and PHM had no effects in unstimulated tissue preparations. Both peptides concentration‐dependently (10‐9‐10‐6m) relaxed CC and CV preparations precontracted with 3 times 10‐6m noradrenaline. In CC the maximum relaxant effect of VIP and PHM was 22PM 11 % and 9 PM 9% and in CV the corresponding values were 82 PM 8% and 93 PM3% respectively. The present study supports the hypothesis of VIP and PHM as neurotransmitters and/or neuromodulators in the nervous c

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1992.tb01931.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.The work was designed to study the effects of a meat meal on glomerular filtration rate (GFR), renal plasma flow (RPF), and plasma concentrations of glucagon, insulin, growth hormone, renin, aldoster‐one, total amino acids, and NH3in healthy humans (H) as well as in patients with Child A liver cirrhosis (LC). The meat meal produced renal hyperaemia and hyperfiltration without changes in the filtration fraction. Fractional Na excretion in urine increased significantly after the meat meal only in LC. Hyperinsulinae‐mia and hyperglucagonaemia were seen at baseline in LC and were not affected by the meat meal, whereas in H glucagon concentration increased significantly over baseline within 30 min from the meat meal and insulin within 60 min. Growth hormone concentration was normal at baseline in LC and increased significantly 120–180 min after the meal, whereas it was not affected in H. Renin and aldosterone were stable in both H and LC. Plasma amino acid concentration began to increase 60 min after the meat meal, when hyperfiltration was present. The data indicate that in human Child A cirrhosis of the liver the renal haemodynamic response to a meat meal is independent of changes in glu

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1992.tb01932.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Erythrocyte shape changes are known to occurin vivoand can readily be inducedin vitro. We have analysed the influence of increasing stomatocyto‐sis produced by 0–0.64 mmol 1‐1chlorpromazine and increasing echinocytosis induced with 0–120 mmol 1‐1salicylate or 0–8 mmol 1‐12,4‐dinitrophenol on suspension viscosities. The morphological index of each sample was determined and related to the suspension viscosity. It was found that the viscosity was increased by echinocytosis in dextran‐free solutions, where no aggregation occurred. The viscosity could be normalized by retransforming echinocytes into discocytes. Under conditions with erythrocyte aggregation (suspension with 4 g dl‐1dextran 70, low shear rate:0.1 s‐1) a small degree of echinocytosis produced the highest viscosity, whereas at higher degrees of echinocytosis the ability to aggregate was reduced and the viscosity was similar to that of discocytes or stomato‐cytes. Erythrocytes incubated in hypotonic medium (constant cell number/volume) had a higher viscosity than cells in iso‐ or hypertonic medium. Severely hypotonic medium led to sphering of erythrocytes which reduced the ability of these cells to aggregate and hence decreased the viscosity of suspensions with dextran at low shear rate. The results indicate that discocytes have the lowest viscosity and thus the best oxygen transport efficiency and that iso‐ to hypertoni‐city provides a lower viscosity and better oxygen transport efficiency than hypotonicity. These results may contribute to the understanding of blo

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1992.tb01933.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.The pharmacokinetics of glycosylated recombinant human granulocyte‐macrophage colony‐stimulating factor (rhGM‐CSF) was studied following intravenous (i.v.) and subcutaneous (s.c.) bolus injection of rhGM‐CSF, 8 μg kg‐1employing a sensitive radioimmunoassay. After a single i.v. bolus injection, an initial high serum level of rhGM‐CSF was observed, followed by a rapid decrease that occurred in two phases with a half‐life (t1/2) α of 20.0PM 5 min and at1/2 β of 68.3PM 8 min. Following s.c. bolus injection the absorption was more prolonged. Peak serum concentrations did not occur until about 15–20 h, and were followed by a more protracted elimination than by the i.v. route.In all patients the single rhGM‐CSF injection led to an increase in peripheral white blood cells (WBC), after a temporary drop of 2–5 h duration. The increase in WBC was of longer duration after s.c. than after i.v. bolus treatment. Since the subcutaneous administration leads to prolonged serum concentration of rhGM‐CSF and prolonged increase in peripheral WBC, it seems preferable to i.v. bolus injection, and as effective as

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1992.tb01934.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.Erythrocyte sodium‐lithium countertransport activity is increased in a subgroup of patients with essential hypertension but activity also rises temporarily during normal pregnancy. It is not known if the mechanism of raised activity is the same in both of these situations. Standard sodium‐lithium counter‐transport activity and its kinetic characteristics (sodium affinity and maximum velocity) were measured in 15 women with a normal pregnancy. The mechanism of raised sodium‐lithium countertransport activity was an increase in maximum velocity. There was no change in sodium affinity. This contrasts with essential hypertension where the mechanism is increased sodium affinity.Sodium‐lithium countertransport activity was also measured in 14 primigravidae whose pregnancies were complicated by hypertension, and mean activity was not significantly higher than in normal pregnancy. However, six women had increased sodium affinity suggestive of essential hypertension and a different underlying mechanism of hypertension to those with normal sodium affinity. Prospective measurement of sodium‐lithium countertransport kinetics may lead to a better understanding of the pathophysiology of hypertension i

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1992.tb01935.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.The rise in blood pressure following the intravenous administration of endothelin‐1 remained unchanged in healthy male volunteers pretreated with either the calcium‐channel antagonist nifedipine (10 mg orally), the cyclo‐oxygenase inhibitor indomethacin (150 mg day‐1for three days) or the immunosup‐pressive agent cyclosporine (5 mg kg‐1body weight for five days). Following administration of nifedipine the rise in plasma concentrations of endothelin‐1 during the infusion of the peptide was markedly higher (P<0.01) than during control experiments without nifedipine. It is concluded that, in healthy men, nifedipine, indomethacin and cyclosporine do not exert a major influence on the pressor action of endothelin‐1. However, nifedipine apparently influences the elimination of endothelin‐1 from the circulati

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1992.tb01936.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Abstract.The effects of intravenously administered somatostatin and vasoactive intestinal peptide (VIP) on bile secretion were studied in 10 patients with complete biliary fistulas. The two peptides were administered both separately and simultaneously. During the infusion of vasoactive intestinal peptide, bile secretion increased by 85%, whereas during somatostatin infusion it decreased by 40%. When the peptides were administered together, the VIP‐induced cholere‐tic effect was not reduced by somatostatin. Vasoactive intestinal peptide infusion increased bicarbonate concentration and output, whereas somatostatin had the opposite effect. The output of chloride also increased following vasoactive intestinal peptide infusion but decreased following somatostatin infusion. The concentration of chloride was unaffected by somatostatin whereas it was decreased by vasoactive intestinal peptide. The output of bile acids was unaffected by vasoactive intestinal peptide and decreased by somatostatin infusion, whereas total lipid concentration increased during somatostatin infusion and decreased when vasoactive intestinal peptide was added. It is concluded that, in man, somatostatin acts on the bile acid‐dependent canalicular bile secretion and also, to some extent, on the ductular secretion, whereas vasoactive intestinal peptide acts strictly at the ductular level. The effects of the two peptides on bile secretion are independent of each

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1992.tb01937.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY