title: Anti-hypertensive effect of metoprolol in spontaneously hypertensive rats.
abstract: 1. Oral and intravenous administration of metoprolol to adult spontaneously hypertensive rats (SHR) with established hypertension lowered arterial blood pressure within 4 days of treatment. 2. Steady state plasma concentrations of metoprolol were similar to those of patients during anti-hypertensive treatment with this drug. 3. The neuroeffector function of portal veins of SHR treated orally for 14 days or intravenously for 4 days was not impaired when studied in vitro. This is in contrast to previous findings after long-term treatment. 4. It is concluded that the anti-hypertensive effect of metoprolol in SHR in many respects resembles that observed in patients. It is suggested that impairment of vasomotor nerve control may contribute to the anti-hypertensive effect of beta-adrenoreceptor antagonists.
mesh_terms: D000818:Animals; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000188:drug therapy*; D008790:Metoprolol / Q000097:blood / Q000627:therapeutic use*; D011412:Propanolamines / Q000627:therapeutic use*; D051381:Rats; D013997:Time Factors; D014666:Vasomotor System / Q000503:physiopathology
chemical_list: D011412:Propanolamines; D008790:Metoprolol