Peripheral ?_1 and ?_2-adrenoceptors involved in attenuating the intracere broventricular histamine-induced carotid sinus baroreceptor reflex inhibition in rats
- VernacularTitle:外周?_1、?_2受体作用减弱脑室注射组胺对颈动脉窦反射的抑制
- Author:
Guoqing WANG
;
Xiping ZHOU
;
Xinghong JIANG
;
Rong ZOU
;
Yuying ZHANG
- Publication Type:Journal Article
- Keywords:
carotid sinus baroreceptor reflex resetting;
histamine;
intracerebroventricular injection;
peripheral ? 1-adrenoceptor;
peripheral ? 2-adrenoceptor;
mean arterial pressure
- From:
Chinese Pharmacological Bulletin
1987;0(02):-
- CountryChina
- Language:Chinese
-
Abstract:
Aim To determine the roles of peripheral ? 1 and ? 2 -adrenoceptors (? 1-AR,? 2-AR) in inhibition of carotid sinus barore ceptor reflex(CSR) induced by intracerebroventricular injection (icv) of histami ne (HA).Methods The left and right carotid sinus regions were i solated from the systemic circulation in 22 male Sprague-Dawley rats anesthetiz ed with pentobarbital sodium.The intracarotid sinus pressure (ISP) was altered in a stepwise ma nner in vivo.ISP-mean arterial pressure (MAP) relationship curve and its ch aracteristic parameters were constructed by fitting to the logistic function wit h five parameters.The changes in CSR performance induced by icv HA and the effec ts of pretreatment with ? 1-AR or ? 2-AR selective antagonist into the per ipheral vein on the responses of CSR to HA were examined.Results icv microinjection of HA (60 ?mol?L -1 in 5 ?l) significantly shifted the ISP-MAP relationship curve upwards (P0.05).Conclusion The intracerebroventricular administration of HA results in a rapid resetting of CSR and a decrease in reflex sensitivity, and the functions of both the peripheral ? 1-AR and ? 2-AR may attenuate CSR resetting induced by icv microinjection of HA. Furthermore,the peripheral ? 1-AR might play an important role in mediating the responses of CSR to central HA.
