ISSN:0250-8095    

DOI:10.1159/000167326

出版商:S. Karger AG    

年代:1986

数据来源: Karger

ISSN:0250-8095    

DOI:10.1159/000167324

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Abnormalities in renal blood flow in man with sustained essential hypertension are reviewed with emphasis on four points: (1) renal blood flow is decreased not only per unit square meter but also as a fraction of cardiac output, a result which is not observed in other organs, (2) the relationship between cardiac output and renal blood flow is reset, so that restriction of arteriolar renal vessels is dominantly preglomerular in origin, (3) the renal abnormalities may be reversed by α-blockade, suggesting an important contribution of the autonomic nervous system, and, finally, (4) the normal sodium balance in steady-state conditions is achieved through adaptive mechanisms involving the venous system and resulting in decreased venous compliance and increased postglomerular and venous hydrostatic pressures

ISSN:0250-8095    

DOI:10.1159/000167325

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The effects on renal function of a single dose of six different β-blockers (atenolol, propranolol, meto-prolol, acebutolol, nadolol, and pindolol) have been evaluated in 51 hypertensive patients with normal glomerular filtration rate (GFR). Most drugs, except pindolol, induce a 10–20% decrease in GFR and renal plasma flow, although differences in the magnitude and the pattern of this fall are evident. The fractional excretion of sodium is generally depressed by 20–40%. These data suggest a limited renal tolerance of most β-blockers during acute administration, irrespective of their pharmacological characteri

ISSN:0250-8095    

DOI:10.1159/000167327

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Experiments were performed in which the effects of two β-blockers, tertatolol [dl-(hydroxy-2’-t-butyl-amino-3’-propyloxy)-8-thiochroman hydrochloride] and propranolol, on mean arterial pressure (MAP), heart rate (HR), and renal function were studied in the conscious sodium-replete dog. In all experiments renal function was evaluated from the effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) assessed respectively by measurement of p-aminohippurate and creatinine clearances. These parameters were measured during two 30-min control periods, after which two further measurements were performed over a similar time period, after intravenous administration of either propranolol (0.5 mg·kg-1; n = 8) or tertatolol (0.05 mg·kg-1; n = 8), these two doses being of equivalent β-adrenoceptor antagonist activity. Administration of propranolol and tertatolol did not change MAP but induced a significant and comparable decrease in HR. After propranolol a significant decrease in ERPF was observed, without any change in GFR or sodium excretion. In contrast, administration of tertatolol resulted in no modification of ERPF, a slight but significant increase in GFR, and a significant increase in sodium and potassium excretion. These results suggest that tertatolol and propranolol though acting similarly on systemic parameters have different effects on renal hemodynamics in the consci

ISSN:0250-8095    

DOI:10.1159/000167328

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The effects of the β-adrenoceptor-blocking drugs tertatolol and propranolol on regional hemodynamics were compared in intact and sinoaortic denervated (SAD) conscious spontaneously hypertensive rats (SHR). Miniaturized Doppler flow probes were used for the continuous determination of changes in flows and resistances in the renal, mesenteric, and hindquarter vascular beds. In intact animals 5 mg/kg propranolol i.v. caused an initial increase and a later gradual fall in mean arterial blood pressure (MAP) and an early rise in all three resistances. In SAD rats the reduction in MAP occurred more readily and no increases in RR and MR were observed. RR even decreased significantly. 0.5 mg/kg tertatolol i.v. caused a similar change in MAP as did propranolol. In contrast, tertatolol increased resistance only in the hindquarter vascular bed, both in intact and SAD animals. These data show an important role of sinoaortic baroreflex activation in the early peripheral vasoconstriction caused by propranolol in conscious SHR. Moreover, the data suggest that tertatolol inhibits the sympathetic nervous system-mediated reflex vasoconstriction

ISSN:0250-8095    

DOI:10.1159/000167329

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The prejunctional β-adrenoceptors present in the isolated perfused kidney of normotensive rats (NR) and spontaneously hypertensive rats (SHR) were compared and the effects of tertatolol on these receptors were investigated. Kidneys of NR (Wistar + Wistar-Kyoto [WKY]) and SHR, were continuously perfused with Tyrode solution at constant flow and the changes in perfusion pressure were monitored. The constrictor responses to norepinephrine (2–8 × 10-10 moles) were slightly but significantly decreased by isoproterenol (2 × 10-7M) to a similar degree in NR and SHR. Tertatolol (3 X 10-7M) did not alter the constriction caused by norepinephrine, but abolished the dilator response to isoproterenol. Electrical stimulation of renal nerves (8 Hz) evoked constrictions in both NR and SHR; these constrictor responses were augmented in the presence of isoproterenol (2 × 10-7M) to a similar extent in NR and SHR. In kidneys of NR and SHR, previously incubated with 3H norepinephrine, renal nerve electrical stimulation (6 Hz) evoked an overflow of the 3H transmitter. This overflow was enhanced by isoproterenol (2 × 10-6M) to a similar degree in NR and SHR. Both the augmented constrictor response and the augmented overflow of 3H norepinephrine caused by electrical stimulation in the presence of isoproterenol, were inhibited by tertatolol (3 X 10-7M). Our results show that the β-receptor agonist isoproterenol evokes comparable effects at prejunctional β-adrenoceptors in kidneys of NR and SHR; they also show that tertatolol is an inhibitor of pre- and postjunctional β-adrenoceptors in the renal circulation o

ISSN:0250-8095    

DOI:10.1159/000167330

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Tertatolol is a noncardioselective β-adrenergic blocking agent without partial agonist activity. Its central and renal hemodynamic effects were compared to those of an equipotent dosage of propranolol in two groups of 10 patients each who developed arterial hypertension and a hyperdynamic circulatory state after head injury. After tertatolol, 5 mg orally, mean arterial blood pressure was unaffected, heart rate decreased by 22% (p < 0.01) and cardiac index by 24% (p < 0.01) while renal blood flow remained unchanged (-5%; not significant) so that the renal fraction of cardiac index was increased by 22% (p < 0.05). After propranolol, 160mg orally, mean arterial blood pressure was not modified, heart rate decreased by 12% (p < 0.01), cardiac index by 16% (p < 0.01) and renal blood flow by 17% (p < 0.01) so that the renal fraction of cardiac index remained unchanged (-3%; not significant). Tertatolol is a potent β-blocking agent comparable to propranolol apart from the fact that it preserves renal perfusion; this peculiar effect is related to a redistribution of the reduced cardiac output to the benefit of the kidne

ISSN:0250-8095    

DOI:10.1159/000167331

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Tertatolol, a new β-blocker, and propranolol, considered a reference β-blocker, were given orally (5 and 160 mg slow release, respectively) for 15 days to two groups of patients with essential hypertension in order to compare their effects on renal hemodynamics. Systolic and diastolic blood pressure, heart rate, and erect plasma renin activity fell significantly in both groups while prostaglandin E2 urinary excretion was unchanged. Tertatolol administration produced increases in glomerular filtration rate, as shown by inulin clearance (+8.9%; p = 0.038) and renal plasma flow, as shown by paraaminohippurate clearance (+13.0%; p = 0.007). In contrast, propranolol administration resulted in a slight decrease in glomerular filtration rate (-2.8%; not significant) and a fall in renal plasma flow (-13.4%; p < 0.001). Comparison between both treatments showed that glomerular filtration rate and renal plasma flow were higher in the patients treated with tertatolol than in those treated with propranolol whereas filtration fraction was lower, which suggests that tertatolol causes a vasodilation of the glomerular afferent arteriole. These results demonstrate that in contrast to propranolol (160 mg), and despite both drugs exhibiting a comparable antihypertensive activity, tertatolol (5 mg) does not alter but even improves renal perfusion in hypertensive patient

ISSN:0250-8095    

DOI:10.1159/000167332

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Tertatolol, a new nonselective β-adrenoceptor blocker, was administered to 11 hypertensive patients in a short-term study. Systolic and diastolic blood pressure and heart rate were significantly decreased when compared to the placebo period: in spite of that glomerular filtration rate and renal plasma flow were unchanged. The administration of metoclopramide (a dopaminergic receptor antagonist) caused a significant reduction of renal plasma flow and a significant rise of renal vascular resistances during placebo, but no change during tertatolol therapy. A possible interference of tertatolol on dopaminergic receptors is discussed as the mechanism reponsible for the unmodified renal plasma flow despite the significant blood pressure lowering with tertatolol

ISSN:0250-8095    

DOI:10.1159/000167333

出版商:S. Karger AG    

年代:1986

数据来源: Karger