Blockade of GABA receptors in periventricular forebrain of anesthetized cats: effects on heart rate, arterial pressure, and hindlimb vascular resistance.
Blockade of GABA receptors in periventricular forebrain of anesthetized cats: effects on heart rate, arterial pressure, and hindlimb vascular resistance.
复制标题
麻醉猫脑室周围前脑 GABA 受体的阻断：对心率、动脉压和后肢血管阻力的影响。
DOI：
10.1016/0006-8993(84)90407-4
复制
发表时间：
1984
期刊：
影响因子：
2.9
通讯作者：
DiMicco,JA
中科院分区：
文献类型：
--
作者：
Schmidt,B;DiMicco,JA
麻醉猫脑室周围前脑中 GABA 能抑制的药理学拮抗作用导致剂量相关（1）交感神经介导的迷走神经切断猫的心率和动脉压增加，以及（2）在迷走神经完整制剂中抑制迷走神经反射激活，其中通过颈脊髓横断防止交感神经作用。在目前对具有完整自主神经通路的猫进行的研究中，类似地给予 GABA 拮抗剂荷包牡丹碱 (BMI) 会导致动脉压、心率以及在测量自体灌注后肢灌注压时产生剂量相关的血管阻力增加。此外，心率与后肢血管阻力变化之间的关系表明，对心率的影响反映了BMI对交感神经和迷走神经压力反射的综合影响。脑室内注射蝇蕈醇（一种有效的 GABA 激动剂）会突然且平行地逆转 BMI 引起的对全身动脉压和血管阻力的影响，而在大多数实验中，尝试通过切断股骨和坐骨神经来在 BMI 反应最严重时急性去后肢神经，从而急剧逆转后肢血管阻力的增加。结果表明，观察到的心血管变化代表了一种综合模式，包括支配心脏和脉管系统的交感神经的兴奋以及反射引起的迷走神经兴奋性的抑制。
Pharmacologic antagonism of GABAergic inhibition in the periventricular forebrain of anesthetized cats caused dose related (1) sympathetically mediated increases in heart rate and arterial pressure in vagotomized cats, and (2) suppression of reflex vagal activation in vagus-intact preparations where sympathetic effects are prevented by cervical spinal cord transection. In the present study performed in cats with intact autonomic pathways, similar administration of the GABA antagonist bicuculline methiodide (BMI) produced dose-related increases in arterial pressure, heart rate, and, when perfusion pressure in the autoperfused hindlimb was measured, vascular resistance. Furthermore, the relationship between heart rate and hindlimb vascular resistance changes suggested that the effects on heart rate reflected the combined sympathetic and vagal baroreflex effects of BMI. Intraventricular administration of muscimol, a potent GABA agonist, elicited abrupt and parallel reversal of BMI-induced effects on systemic arterial pressure and vascular resistance while attempts to acutely denervate the hindlimb at the height of the BMI response by cutting the femoral and sciatic nerves sharply reversed the increase in hindlimb vascular resistance in most experiments. The results suggest that the cardiovascular changes observed represent an integrated pattern consisting of excitation of sympathetic nerves innervating the heart and vasculature along with suppression of reflex evoked vagal excitability.