The effects of injections of arginine vasopressin (AVP) into the nucleus tractus solitarius (NTS) on mean arterial pressure (MAP), heart rate (HR) and plasma concentrations of noradrenaline and adrenaline were investigated in conscious, unrestrained rats. Injection of 2 ng AVP into the NTS significantly increased MAP but not plasma catecholamine concentrations, while injection of 10 ng AVP significantly increased MAP and plasma noradrenaline and adrenaline levels. Neither dose of AVP produced any change in HR. The vehicle did not affect MAP, HR or plasma catecholamine levels. Injection of a specific pressor antagonist of AVP, d(CH2)5Tyr-(Me)AVP (10 ng), did not change MAP, HR or plasma noradrenaline or adrenaline levels. These results suggest that the NTS is a central site of the pressor action of AVP. However, since the injection of the AVP antagonist did not reduce MAP or plasma noradrenaline or adrenaline levels, it suggests that AVP does not act tonically at the NTS to influence sympathoadrenal outflow.
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机译：在清醒无拘束的大鼠中，研究了对孤束核（NTS）注射精氨酸加压素（AVP）对平均动脉压（MAP），心率（HR）以及去甲肾上腺素和肾上腺素血浆浓度的影响。向NTS中注射2 ng AVP可以显着提高MAP，但不会增加血浆儿茶酚胺的浓度，而注射10 ng AVP则可以显着提高MAP和血浆去甲肾上腺素和肾上腺素的水平。两种剂量的AVP均不会引起HR的任何变化。该媒介物不影响MAP，HR或血浆儿茶酚胺水平。注射AVP的特异性加压拮抗剂d（CH2）5Tyr-（Me）AVP（10 ng），不会改变MAP，HR或血浆去甲肾上腺素或肾上腺素水平。这些结果表明NTS是AVP加压作用的中心部位。但是，由于注射AVP拮抗剂并不能降低MAP或血浆去甲肾上腺素或肾上腺素的水平，因此表明AVP在NTS上没有调性作用，影响交感肾上腺流出。
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