The Experimental Research Of Renal Aquaporin-3 Expression In Obstructive Jaundice

IntroductionObstructive jaundice can induce acute renal failure, according to the cultural data, the occurrence rate of Acute renal failure in obstructive jaundice reach to 6% 18% , mortality of the disease is up to 32% - 100%. The renal tubule water sodium reabsorption disfunction in obstructive jaundice take place early in renal impairment than the decrease of the kidney blood and the occurrence of the glomerular filtration disfunction, the urinary concentration disfunction is the earlier period of the renal impairment in obstructive jaundice. In 1991, Ager etc. have discovered a kind of protein which can transport water between the cell membrane for the frist time, named Aquaporin ( AQPs ) . More than ten categories have been discovered later , eight of them distributed in the kidney be called AQP_{0,1,2,3,4,6,7} and AQP₈. The present study confirms that AQPs play an important role in reabsorb water and urinary concentration ,and in maintain the water balance of bodys. The AQP - 3 locates in basolateral membrane of connecting tubule mainly, AQP — 3 not only can transport water but also can transport some small molecule material such as urea and glycerin. , and the urea have important effect on the concentrated mechanism of kidney. Mensurated and analyzed the different expression of AQP — 3mRNA and AQP — 3 in obstructive jaundice different periods by making a experimental modle of wistar rat , and clarified the relationship between the Aquaporin - 3 expression and renal disfunctionin.Materials and MethodsThere are fourty adult male Wistar rat in the experiment, the weight be-tween 200 - 250g, divided them into A, B, C, D group (n = 10 ) randomly, A group is which be obstructive jaundice for 7 days. B group is the control group for A group,C group is which be obstructive jaundice for 14 days, D group is the control group for C group. The A,B and C,D groups experimental animal will been killed respective after 7 days and 14 days when the obstructive jaundice experimental animal model are builded up, examine each of experiment animal's liver function and renal function, then judge whether the animal model meet this experiment's request, mensurate the expression of AQP - 3 mRN A in kidney by RT - PCR technique, and mensurate the content of AQP - 3 in kidney using Western blotting method. The data handle: Adopt the SPSS11.0 software carries on statisticsing analysis.Experiment result1. There is no difference in CREA among each group experimental wistar rat;Level of UREA has difference between groups which be obstructive jaundice for 7 and 14 days, and there are no difference among the rest group.2. The content of AQP - 3 have shown significant difference between groups which be obstructive jaundice for 7 and 14 days and groups which be obstructive jaundice for 14 days and it's control group using the Western blotting method , between groups which be obstructive jaundice for 7 days and it's control group the P value less than 0. 05 , there is difference, but it is biger than 0. 05 between groups which be obstructive jaundice for 14 days and it's control group, there isn "I statistics meaning in it.3. The expression of AQP -3 mRN A have already shown significant difference between groups which be obstructive jaundice for 7days and it's control group and groups which be obstructive jaundice for 14 days and it's control group by using the PCR technique , The expression between the groups which be obstructive jaundice for 7 and 14 days and control groups which be obstructive jaundice for 7 and 14 days groups haven't shown difference.DiscussionThe Pathogenetic mechanisms that OJ can induce renal disfunction islit explained clearl incompletely, its occurrence have some relationships to some factor such as endotoxemia, bile acid cytotoxicity, INF, renal ischemia - reperfusion injury, reduction in effective plasma volume, water - electrolyte disbalance and so on.In the earlier period (before the change of CREA and UREA) of the Obstructive jaundice can appear the expression of AQP - 3 mRNA upregulation in kidney, and it would increase along with time extension, but the contents AQP — 3 in the kidney downregulate obviously. There may be some interferential factor in the process that AQP - 3 mRNA translate into protein AQP - 3. Owing to the AQPs in urine are secreted according to the certain ratio of the AQPs content in the kidney , we can measure the AQPs content in the urine, and estimate the AQPs content in the kidney. If it be the new standard to examine concentrated function of the kidney, doubtless contribute to raise the diagnosis rate that obstructive jaundice induce the renal function injure in the earlier period.ConclusionThere is no obvious change in CREA when Obstructive jaundice took place in 14 days;The UREA can increase after Obstructive jaundice take place 7 days ago;The expression of AQP - 3 mRNA upregulate in the early period of Obstructive jaundice , but it do not upregulate continuable as the time of Obstructive jaundice;The expression of AQP — 3 downregulate in early period of Obstructive jaundice, and along with the Obstructive time of extension, the expression of AQP -3 has a trend of downregulate gradually.