The post-haemorrhagic vasopressin release into the blood

The aim of the present study was to compare the influence of the renin-angiotensin and sympathetic system in the process of post-haemorrhagic vasopressin release. A dialysis of the venous blood from the sella turcica region was performed in male rats under anaesthesia. The animals were divided into eight experimental groups: 1). control; 2). bleeding; 3). 20 days after superior cervical ganglionectomy; 4). 20 days after superior cervical ganglionectomy and bleeding; 5). injection of captopril; 6). injection of captopril and bleeding; 7). 20 days after superior cervical ganglionectomy and injection of captopril; 8). 20 days after superior cervical ganglionectomy, injection of captopril and bleeding. The content of vasopressin in dialysates was determined by radioimmunoassay. In control rats the release of vasopressin into dialysates was constant during 180 min of the experiment. Bleeding, as well as, superior cervical ganglionectomy caused an increase in vasopressin release. Captopril did not change vasopressin release in comparison to control group. Furthermore, vasopressin release after both, bleeding and sympathetic denervation performed simultaneously was significantly abolished. We conclude that renin-angiotensin, as well as, sympathetic nervous system are involved in the increased post-haemorrhagic vasopressin release.