Minami M, Togashi H, Sano M, Saito I, Morii K, Nomura A, Kurosawa M, Yoshioka M, Saito H
Hokkaido Igaku Zasshi. 1984 Jul;59(4):471-7.
The study was undertaken to elucidate the effect of beta 1 adrenoceptor blocking agent, metoprolol, on water drinking activity in Wistar Kyoto rats (WKY). Both 7 day (10mg/kg/day) oral administration of metoprolol and propranolol did not produce any changes in the systolic blood pressure of WKY. However, metoprolol produced a significant decrease in heart rate in WKY. Neither the propranolol treated rats nor the control (non-drug group) rats showed any significant changes in heart rate. Heart rates were significantly changed in the metoprolol group as compared with the other two groups. This finding reconfirms that metoprolol has beta 1 selectivity. Drinking activity, an indicator of central nervous function, did not change after metoprolol administration. Power spectral analysis of water drinking activity did not reveal any changes in rhythm in respect to periodicity in the metoprolol group. Although water drinking activity is synchronized with urinary catecholamine and aldosterone excretion rates, urinary catecholamine and aldosterone excretion rates did not change after metoprolol administration. These findings suggest that it is the beta 1 adrenergic blocking action of a bradycardia-producing dose of metoprolol that prevented any change in water drinking behavior in WKY.
本研究旨在阐明β1肾上腺素能受体阻断剂美托洛尔对Wistar Kyoto大鼠（WKY）饮水行为的影响。连续7天口服美托洛尔（10mg/kg/天）和普萘洛尔均未引起WKY大鼠收缩压的任何变化。然而，美托洛尔使WKY大鼠心率显著降低。普萘洛尔处理组大鼠和对照组（非药物组）大鼠的心率均未出现任何显著变化。与其他两组相比，美托洛尔组的心率有显著变化。这一发现再次证实美托洛尔具有β1选择性。作为中枢神经功能指标的饮水行为在给予美托洛尔后未发生改变。对饮水行为的功率谱分析未显示美托洛尔组在周期性节律方面有任何变化。尽管饮水行为与尿儿茶酚胺和醛固酮排泄率同步，但给予美托洛尔后尿儿茶酚胺和醛固酮排泄率未发生变化。这些发现表明，产生心动过缓剂量的美托洛尔的β1肾上腺素能阻断作用可防止WKY大鼠饮水行为发生任何改变。
