Journal of cardiovascular pharmacology
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J. Cardiovasc. Pharmacol. · Jul 1990
Enalaprilat effects renin-angiotensin and adrenergic response to induced hypotension in the rabbit.
The effects of enalaprilat on the renin-angiotensin system and sympathetic nervous system during sodium nitroprusside (SNP)-induced hypotension and halothane anesthesia were studied in three groups of New Zealand white rabbits. Two groups of rabbits (E and EH) were treated with an infusion of enalaprilat at 3.5 micrograms/kg/min i.v. One enalaprilat-treated group (EH) and the third, untreated group (H) received SNP to induce hypotension. ⋯ In group EH, PRA levels rose sharply and remained elevated. Plasma NE and EPI levels increased slightly with a decline in the SNP dose requirement. Group E demonstrated a rise in PRA levels, accompanied by unchanged NE and EPI levels and MAP during the study period.(ABSTRACT TRUNCATED AT 250 WORDS)
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J. Cardiovasc. Pharmacol. · Mar 1990
The effects of captopril on the renin-angiotensin system and the sympathetic nervous system during sodium nitroprusside-induced hypotension in the halothane-anesthetized rabbit.
Three groups of New Zealand white rabbits were used to study the effects of captopril on the renin-angiotensin system and sympathetic nervous system during sodium nitroprusside (SNP)-induced hypotension and halothane anesthesia. Two groups of rabbits (C and CH) were treated with captopril 2 mg/kg i.v. One captopril-treated group (CH) and the third, untreated group (H) received SNP to induce hypotension. ⋯ Plasma NE levels increased, while EPI levels remained unchanged with a decline in the SNP dose requirement. The C group demonstrated a rise in PRA levels, accompanied by unchanged NE and EPI levels and MAP during the study period. Captopril administration decreased the SNP dose requirement and significantly decreased the sympathetic response (measured by NE and EPI levels) in group CH as compared to the H group.(ABSTRACT TRUNCATED AT 250 WORDS)
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J. Cardiovasc. Pharmacol. · Jan 1990
Randomized Controlled Trial Clinical TrialDrug interactions: the new phosphodiesterase inhibitor enoximone and the calcium channel blocker nifedipine in coronary surgery patients--influence on hemodynamics and plasma concentrations.
The calcium channel blocker nifedipine and the new phosphodiesterase (PDE) inhibitor enoximone are used in the treatment of cardiovascular diseases. Since both substances are acting on slow calcium channels and because systemic elimination of these two agents is dependent on oxidative drug metabolizing enzyme activity, this study was performed in order to investigate hemodynamic changes and effects on plasma levels when both substances are given simultaneously. Forty-five patients undergoing aortocoronary bypass grafting were randomly subdivided into three groups: (a) group (n = 15) received 0.3 micrograms/kg/min of nifedipine as an infusion (N patients); (b) group (n = 15) received 0.5 mg/kg of enoximone as a bolus (E patients); and (c) group (n = 15) received nifedipine and enoximone in the same dosages (E + N patients). ⋯ Plasma concentrations of enoximone and enoximone sulfoxide were not affected by nifedipine infusion and showed a comparable course in E and E + N patients. Nifedipine plasma level dropped to values less than 15 ng/ml at the end of extracorporeal circulation in N and E + N patients. It can be concluded that enoximone improved hemodynamics even in patients pretreated with nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)
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J. Cardiovasc. Pharmacol. · Apr 1988
Beneficial effects of fenoldopam on systemic and regional hemodynamics in rabbits with congestive heart failure.
Fenoldopam (SKF 82526 J) is a selective DA-1 receptor agonist and thus of a potential benefit for promoting afterload reduction, renal vasodilatation, and diuresis in congestive heart failure. To examine the acute effects of fenoldopam in heart failure, studies were performed in control rabbits (n = 6) and in rabbits with chronic congestive heart failure (CHF, n = 6) induced by adriamycin treatment. Cardiovascular variables and regional blood flows were determined before and after an infusion of fenoldopam (150 micrograms/kg total dose). ⋯ Plasma renin and norepinephrine (NE) levels increased after fenoldopam in both control and CHF rabbits. These results show that acute administration of fenoldopam produces favourable systemic and regional hemodynamic responses in rabbits with low output heart failure. However, long-term benefit remains to be demonstrated, particularly considering the hormonal responses.
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J. Cardiovasc. Pharmacol. · Jan 1988
Review Comparative StudyHemodynamic effects of beta-blocking compounds possessing vasodilating activity: a review of labetalol, prizidilol, and dilevalol.
The cardinal hemodynamic disturbance in established essential hypertension is an increased total peripheral resistance. Monotherapy with conventional beta-blockers lowers blood pressure usually without any significant fall in total peripheral resistance. Generally, cardiac output is reduced at rest as well as during exercise. ⋯ Preliminary data indicate a reduction in blood pressure--mainly due to a fall in total peripheral resistance. Studies in elderly patients or in patients with reduced left ventricular function seem to indicate that the drug might be used without deterioration of the heart pump function. Although antihypertensive properties of dilevalol have been extensively studied and are defined, the exact position of dilevalol among antihypertensive drugs will be more precisely determined in future studies.