摘要:

SUMMARY1. The role of angiotensin as a modulator of proximal glomerulotubular (GT) balance was investigated in anaesthetized rats by examining the relationship between glomerular filtration rate (GFR) and absolute proximal reabsorption (APR) during removal of endogenous angiotensin II (AII) and III (AIII) with enalaprilat (CEI) and then during their subsequent replacement by intravenous infusions.2. Enalaprilat lowered mean arterial blood pressure (MABP) and increased renal blood flow (RBF), GFR, urine flow rate and sodium excretion. Filtration fraction (FF) was not altered. Absolute proximal reabsorption, derived from fractional lithium clearance, increased by only 48% of the change expected for ‘perfect’ GT balance.3. Angiotensin II replacement corrected MABP, GFR and plasma renin level, but reduced RBF and increased FF; APR was decreased and GT balance was restored. Urine flow and sodium excretion remained above control values with AII.4. Replacement with AIII did not correct the hypotension but completely reversed the renal and renin responses to enalaprilat and restored GT balance without affecting FF.5. It was concluded that the relation between proximal reabsorption and GFR is considerably modified by the intrarenal angiotensin concentration. The findings are best explained by a direct stimulation of proximal tubular sodium transport by angiotensin at the concentrations existing in anaesthetized r

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1987.tb01505.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SUMMARY1. The neonates of sheep and other species have a decreased gastric acid secretion but an elevated plasma gastrin concentration.2. Since low gastric acid secretion is a stimulus for gastrin release in mature animals the present study examined whether the relative hypochlorhydria in the sheep fetus was sustaining the hypergastrinaemia.3. Fetal plasma gastrin was measured following fetal gastric acidification (pentagastrin infusion) and gastric neutralization (parietal cell blockade with the proton pump inhibitor omeprazole) in chronically cannulated fetal sheep from 101 days until term (145 days).4. Acutely raising gastric pH with omeprazole increased plasma gastrin in the mature sheep. However, in the fetus increasing the pH with omeprazole or decreasing pH with pentagastrin had no effect on fetal plasma gastrin. This was true for fetuses from all age groups.5. The results indicate that the gastric acid‐gastrin feedback loop is not functional in the fetus and that the hypergastrinaemia at birth is therefore not the result of the relative hypochlorhydria.6. The time after birth when the gastric acid‐gastrin feedback loop matures remains to be determi

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1987.tb01506.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SUMMARY1. This study investigated the effects of dietary modification of prostaglandin (PG) synthesis on blood pressure regulation in DOCA/salt‐treated rats.2. After an initial 4 week period on either a 2‐series PG ‘inhibitory’ diet of fish oil (Max EPA), A ‘stimulatory’ diet of safflower oil or a control diet of saturated fat, three groups of rats were placed on a DOCA/salt regimen for a further 4 weeks. Another group on the saturated fat diet continued their diet without DOCA/salt administration.3. All the DOCA‐treated groups showed a marked increase in blood pressure. However, both polyunsaturated fat (PUFA)‐fed groups had blood pressures significantly lower then the saturated fat control.4. Rats on the Max EPA showed impaired ability to generate prostanoidsin vitro(serum, aorta and kidney) andin vivo(urinary PG excretion). DOCA administration increased urinary PGE2excretion.5. Thus, dietary suppression of 2‐series PG is not accompanied by accelerated DOCA/salt hypertension. The reduction in blood pressure observed in both the safflower and Max EPA‐fed groups may be due to PUFA‐induced changes in c

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1987.tb01507.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SUMMARY1. The aim of this study was to determine if stimulation of a β‐adrenoceptor on endothelial cells could release an endothelium‐derived relaxing factor (EDRF) similar to that released by acetylcholine.2. In dog coronary rings preconstricted with PGF2αor serotonin, removal of the endothelium did not alter the relaxant responses to isoprenaline. However, in rings preconstricted with the thromboxane‐mimetic U46619, removal of the endothelium enhanced the response to isoprenaline.3. The vasorelaxant responses to isoprenaline in endothelium‐denuded rings were inhibited in a concentration‐dependent manner by the specific β1‐adrenoceptor antagonist CGP‐20712A (3–100 nmol/l), but were not altered by the β2‐adrenoceptor antagonist ICI‐118551 (30 nmol/l).4. The vasorelaxant responses to isoprenaline in the presence of CGP‐20712A (30 nmol/l) or ICI‐118551 (30 nmol/l) were not impaired by removal of the endothelium.5. Endothelium‐dependent vasorelaxant responses to acetylcholine and bradykinin were not altered by isoprenaline (0.1 μmol/l) in the presence of CGP‐20712A (30 nmol/l).6. Therefore, the β‐adrenoceptors on dog coronary artery smooth muscle which produce relaxation are predominantly of the β1‐subtype. Stimulation of any β2‐adrenoceptors on the endothelium in dog coronary artery does not release EDRF, and does not modulate endothelium‐depen

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1987.tb01508.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SUMMARY1.In situcanine lungs were perfused in the presence or absence of the nerves which coursed to the heart and lungs (the cardiopulmonary nerves, CPN).2. A right heart‐bypassed preparation was made first, so that the respiratory and circulatory conditions could be controlled beforehand. It was then switched to a lung‐perfusion preparation, in which the lungs receive all influences of sudden cessation of the brain and systemic circulations solely via the CPN. Hydrostatic mechanisms causing pulmonary oedema were excluded by adjusting the pulmonary arterial pressure under 300 mmH2O (<24 mmHg).3. Accumulation of extravascular lung water and the rate of reservoir blood loss were significantly lower in the CPN‐severed group than in the CPN‐intact group.4. After perfusion of 90 min, total loss of reservoir blood was correlated significantly with extravascular water content in lungs. The former was larger than the latter.5. Elevation of left atrial pressure caused an increase in the rate of reservoir blood loss. When the CPN was severed, the relation between these two parameters was shifted to the right.6. These findings indicate a CPN‐mediated genesis of permeability pulmona

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1987.tb01509.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SUMMARY1. Fourteen healthy male volunteers were studied to assess the effects ofPanax ginsengon blood alcohol clearance, utilizing each subject as his own control.2. At 40 min after the last drink, the blood alcohol level in the test group receiving ginseng extract (3 g/65 kg body weight) along with alcohol (72 g/65 kg body weight) was about 35% lower than their control values.3. When the blood alcohol level was compared on individual bases, alcohol concentrations in 10 out of 14 test subjects ranged from 32 to 51% lower than their control values.4. These results demonstrate thatP. ginsengextract enhances blood alcohol clearance in man.

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1987.tb01510.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

SUMMARY1. Platelet monoamine oxidase (MAO) activity was investigated in 30 patients with Huntington's disease and compared with the activity in a control group.2. Significantly elevated activity was found in the patients (P<0.05;t‐test) when same sex contrasts were carried out to account for the well known influence of sex on MAO activity.3. The mean MAO activity in male patients was 23.5±6.0 nmol/mg protein per h and female patients was 29.5 ± 8.9 nmol/mg protein per h using tyramine as the substrate.4. The possible influence of environmental factors on the results is discus

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1987.tb01511.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Textbook of Adverse Drug Reactions, 3rd edition. Edited by D. M. DaviesThe Biochemical Basis of Neuropharmacology, 5th edn. By Jack R. Cooper, Floyd E. Bloom and Robert H. Roth

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1987.tb01512.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY