Goraca A, Orłowska-Majdak M, Traczyk W Z
Department of Physiology, Medical University of Lodz, Poland.
J Physiol Pharmacol. 1996 Jun;47(2):257-67.
It has previously been demonstrated that the cardiodepressant activity is present in the bovine hypothalamic extract and in the fluid incubating the posterior pituitary lobe "in situ". The present study was an attempt to reveal if the cardiodepressant factor and vasopressin were simultaneously released from the pituitary into blood. The samples of venous blood flowing from the sella turcica and, for comparison, from the posterior paw were collected in anaesthetized rats. Blood from the sella turcica was collected with a fine cannula inserted into the internal maxillary vein. The concentration of vasopressin in blood plasma was determined by radioimmunoassay and cardiodepressant activity--using a biological test on a spontaneously discharged pacemaker tissue of the right auricle of the right heart atrium. Stimulation of the central ends of the cut vagus nerves or intra-arterial infusion of angiotensin II simultaneously caused an increase in the cardiodepressant activity and vasopressin concentration in the sella turcica venous blood. The cardiodepressant activity and vasopressin concentration was also enhanced to some degree in blood outflowing from the posterior paw. Present results indicate that both vasopressin and the cardiodepressant factor are released into blood from the posterior pituitary lobe.
先前已经证明，牛下丘脑提取物以及“原位”孵育垂体后叶的液体中存在心脏抑制活性。本研究旨在揭示心脏抑制因子和血管加压素是否同时从垂体释放到血液中。在麻醉大鼠中收集从蝶鞍流出的静脉血样本，并作为对照，收集后爪的静脉血样本。用细套管插入上颌内静脉收集蝶鞍处的血液。通过放射免疫测定法测定血浆中血管加压素的浓度，并通过对右心房右心耳的自发放电起搏组织进行生物学测试来测定心脏抑制活性。刺激切断的迷走神经中枢端或动脉内输注血管紧张素II同时导致蝶鞍静脉血中心脏抑制活性和血管加压素浓度增加。后爪流出的血液中，心脏抑制活性和血管加压素浓度也有一定程度的升高。目前的结果表明，血管加压素和心脏抑制因子都从垂体后叶释放到血液中。
