Effect of repeated and prolonged +Gz exposure on endocrine function of vessel in a rabbit model of atherosclerosis / 解放军医学杂志

ABSTRACT

Objective To investigate the effect of repeated and prolonged +Gz exposure on endocrine function of vessel in a rabbit model of atherosclerosis. Methods Twenty-four male New Zealand white rabbits were used to establish the model of atherosclerosis, and then randomly divided into control group and +Gz exposure group (12 each). Animals in control group underwent no +Gz exposure, while those in +Gz exposure group underwent +Gz exposure for 4, 8, and 12 weeks respectively (4 animals at each time point), and 4 animals from each group were sacrificed at each time point. The levels of angiotensin II (Ang II), endothelin (ET), heme oxygenase-1 (HO-1), carbon monoxide (CO) and cyclic guanosine-3', 5'-monophosphate (cGMP) were measured by radioimmunoassay and biochemical method, and the ultrastructure of aortic intima was examined by electron microscopy. Results Along with the prolongation of +Gz exposure, the contents of Ang II, ET, HO-1, CO and cGMP were increased in +Gz exposure group (P<0.05), but the increase stopped at the 12th week, and no obvious change in the above indices was observed in control group (P=0.05). The foam cells and collagen content under the aortic intima and in the shallow layer of aortic media were slightly increased in control group, but the foam cells and the interstitial collagen fibers were greatly increased after +Gz exposure for 8 and 12 weeks as compared with that in control group. Conclusion Repeated and prolonged +Gz exposure may induce the production of Ang II and ET, increase the secretion of HO-1, CO and cGMP, thus play a potential role in protecting the vessels from further injuries.