Expression Of AQP3 And AQP4 In Spontaneously Hypertensive Rats Kidneys After Blocking Of AT1 Receptor

Objective: To observe the changes of blood pressure and the expression of aquaporin 3,4 in the kidney of 12 weeks old spontaneously hypertentive rats after intragastric treatment of valsartan,to investigate the expression of aquaporin 3,4 in spontaneously hypertensive rats kidneys after valsartan blocking of AT1 receptor,and to provide a potential target for the development of new antihypertensive drugs.Methods: Spontaneously hypertentive rats were randomly divided into 4 groups,including the group of physiological saline lavage rats(WKY-N),the group of valsartan lavage rats(WKY-V),the group of physiological saline lavage rats with spontaneous hypertension(SHR-N)and the group of valsartan lavage rats with spontaneous hypertension(SHR-V),with 6rats in each group.After a week of adaptive feeding,blood pressure was measured by noninvasive tail artery in a fixed period of time.Each rat was measured three times.The SHR-V group and WKY-V group rats were intragastric administration of valsartan 10mg(kg/day),the SHR-N group and WKY-N group rats were intragastric administration of same volume saline with experimental time increased to 28 weeks,the dosage of intragastric administration was adjusted according to the change of body weight in rats.After 28 weeks,rats were respectively taken abdominal aorta blood measuring aldosterone value,the expression of AQP3 m RNA and AQP4 m RNA were respectively detected by real-time quantitative reverse transcription polymerase chain reation,immunohistochemistry and western blot.The results of these indexes were analyzed.Results: 1.There was no significant difference in blood pressure between the group of WKY-N and the group of WKY-V(P > 0.05).Compared with the blood pressure of the group of SHR-N,the group of SHR-V was better.There was no significant difference inblood pressure with the prolongation of the experimental time,the blood pressure of the two groups was statistically significant(P < 0.05).The blood pressure of the group of SHR-N increased significantly with the increasing of experimental time.At 28 weeks after intragastric administration,the blood pressure of SHR-N was higher than that of other control groups,the difference was statistically significant(P < 0.05).2.The result of aldosterone: The level of aldosterone in the group of SHR-V was significantly higher than the groups of WKY-N and WKY-V,the difference was statistically significant(P < 0.05).The level of aldosterone in the group of SHR-N was higher than the group of WKY-N and WKY-V,the difference was statistically significant(P < 0.05).The level of aldosterone in the group of SHR-V was significantly higher than the group of SHR-N,the difference was statistically significant(P < 0.05).3.The result of Immunohistochemistry: The expression of AQP3 in the group of SHR-N was the lowest,which was weaker than that in the other three groups,the difference was statistically significant(P < 0.05).The expression of AQP3 in the group of SHR-V was higher than the group of SHR-N,the difference was statistically significant(P < 0.05).The expression of AQP4 in the group of WKY-N and WKY-V was higher than the group of SHR-N and SHR-V,the difference was statistically significant(P < 0.05);The expression of AQP4 in the group of SHR-V was higher than the group of SHR-N,the difference was statistically significant(P < 0.05).4.The result of real-time quantitative reverse transcription polymerase chain reation: The expression of AQP3 m RNA in the group of SHR-V was significantly higher than that of the three groups,the difference was statistically significant(P < 0.05);The expression of AQP3 m RNA in the group of SHR-N was higher than the group of WKY-N and WKY-V(P < 0.05).The expression of AQP4 m RNA in the group of SHR-V was the most than that of the other three groups;The expression of AQP4 m RNA in the group of SHR-N was higher than the group of WKY-N and WKY-V(P < 0.05).5.The result of western blot: The expression of AQP3 and AQP4 in the group of SHR-V was higher than the group of SHR-N,the difference was statistically significant(P < 0.05);There was no significant difference in the expression of AQP3 and AQP4 between the group of WKY-N and the group of WKY-V(P < 0.05);The expression of AQP3 and AQP4 in the group of SHR-N was lower than the group of WKY-N and WKY-V,the difference was statistically significant(P < 0.05).Conclusions: 1.Blocking of AT1 receptor has a good effect on controlling of blood pressure in the spontaneously hypertentive rats,and can improve the level of aldosterone in the plusma,and promote the regulation of aldosterone in the basal membrane of the main cell of the liquid,thereby affecting the regulation of blood pressure.2.Blocking of AT1 receptor can promote the expression of m RNA and protein AQP3 and AQP4 on the kidney of spontaneously hypertentive rats,then regulating and reducing the blood pressure.