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[Role of rennin-angiotensin system in cholinergic agonist carbachol-induced cardiovascular responses in ovine fetus.] [Article in Chinese]

GENG Chun-Song, WAN Zhen, FENG Ya-Hong, FAN Yi-Sun^*

Department of Clinical Laboratory； Department of Obsterics and Gynecology, Suzhou Kowloon Hospital, Shanghai Jiao Tong University Medical School, Suzhou 215021, China； Department of Cardiology, Jianhu Hospital, Nantong University, Nantong 224700, China

Abstract

To investigate the mechanisms underlying the cholinergic agonist carbachol-induced cardiovascular responses, changes of renin-angiotensin system were examined in fetal hormonal systems. In the ovine fetal model under stressless condition, the cardiovascular function was recorded. Blood samples were collected before (during baseline period) and after the intravenous administration of carbachol. Simultaneously, the levels of angiotensin I (Ang I), angiotensin II (Ang II) and vasopressin in the fetal plasma were detected by immunoradiological method. Also, blood gas, plasma osmolality and electrolyte concentrations were analyzed in blood samples. Results showed that in chronically prepared ovine fetus, intravenous infusion of carbachol led to a significant decrease of heart rate (P < 0.05), and a transient decrease followed by an increase of blood pressure (P < 0.05) within 30 min. After the intravenous infusion of carbachol, blood concentrations of Ang I and Ang II in near-term ovine fetus were both significantly increased (P < 0.05); however, blood concentration of vasopressin, values of blood gas, electrolytes and plasma osmolality in near-term ovine fetus were not significantly changed (P > 0.05). Blood levels of Ang I and Ang II in the atropine (M receptor antagonist) + carbachol intravenous administration group was lower than those in the carbachol group without atropine administration (P < 0.05). In conclusion, this study indicates that the near-term changes of cardiovascular system induced by intravenous administration of carbachol in ovine fetus, such as blood pressure and heart rate, are associated with the changes of hormones of circulatory renin-angiotensin system.

Key words: Blood pressure; ovine fetus; carbachol; renin-angiotensin system

Received: 2011-08-18　　Accepted: 2012-04-12

Corresponding author: 樊一笋　　E-mail: fanyisun@hotmail.com

Citing This Article：

GENG Chun-Song, WAN Zhen, FENG Ya-Hong, FAN Yi-Sun. [Role of rennin-angiotensin system in cholinergic agonist carbachol-induced cardiovascular responses in ovine fetus.] [Article in Chinese]. Acta Physiol Sin 2012; 64 (3): 303-307 (in Chinese with English abstract).