梯度渗透压对大鼠内髓集合管细胞增殖的影响

目的 研究氯化钠梯度渗透压对内髓集合管（Inner medullary collecting duct，IMCD）细胞增殖的影响。方法采用胶原酶消化和低渗溶解法分离培养SD大鼠原代IMCD细胞。在正常培养基中培养至90％以上细胞融合后，将细胞分为低渗（200mosmol／kg），等渗（300mosmol／kg）和高渗（600mosmol／kg）培养基组。在12h和24h分别应用MTT法（甲基噻唑基四唑）细胞毒性检测活细胞数目和流式细胞仪检测细胞周期和凋亡率，评价细胞的梯度渗透压耐受性。结果IMCD细胞有很强的渗透压耐受性，IMCD细胞在改变渗透压环境12h时，高渗环境下细胞凋亡率显著高于低渗和等渗环境（1．1％±0．10％V80．565％±0．096％，P〈0．05；0．104％±0．08％，P〈0．05）；而24h时高渗环境下细胞凋亡率略低于低渗环境（P〉0．05），但仍高于等渗环境（P〉0．05）。结论高渗环境可以抑制IMCD细胞的生长，12h作用较显著；而24h低渗环境对IMCD细胞的抑制作用增加。

The effect of gradient osmotic pressure on the proliferation of inner medullary collecting duct cell in rats

Objective To investigate the change of the proliferation of inner medullary collecting duct (IMCD) cell under the sodium chloride gradient osmotic pressure circumstance.Methods Collagenase digostion and hypotonic dissolve were used to isolate and culture primary IMCD cell of Sprague-Dawley rat.Cells were divided into hypotonic medium(200 mosmol/kg),isotonic medium(300 mosmol/kg) and hpertonic medium(600 mosmol/kg) groups,after 90% confluence in the normal culture medium.The cellular cytotoxicity was analyzed by MTT assay(methyl thiazolyl tetrazolium) and flow cytometer was used to detect cell cycle and apoptosis ratio.Results IMCD cells were resistant to osmotic pressure change.Cell apoptosis ratio under hypertonic circumstance was significantly higher than hypotonic and isotonic groups after 12 hours treatment(1.1%±0.10% vs 0.565% ±0.096%,0.104%±0.08%,P＜0.05).Cell apoptosis ratio in hypertonic circumstance was slightly lower than hypotonic group (P＞0.05) but higher than isotonic group(P＞0.05) after 24 hours treatment.Conclusion The proliferation of IMCD cell was inhibited under hypertonic circumstance,especially after 12 hours treatment,and the inhibitory effect of hypotonic circumstance increased after 24 hours treatment.