孕期母鼠体内给予尼古丁对子代水盐代谢的影响

目的观察孕期母鼠体内给予尼古丁对子代肾素血管紧张素系统（RAS）调控的水盐代谢的影响。方法妊娠期母鼠皮下注射尼古丁,检测其胎鼠和成年子代鼠（4个月）体质量、血钠离子（Na^＋）和钾离子（K^＋）浓度及血浆渗透压（Osm）水平;记录成年子代鼠在脱水24h后氯化钠（1.8%NaCl）和水的摄取量,并检测其脑内血管紧张素受体AT1R、AT2R蛋白的表达。结果孕期母鼠体内经尼古丁刺激,胎鼠的体质量明显降低但其成年子代鼠的体质量与对照组无明显差异（P〉0.005）;胎鼠及成年子代鼠循环血液中Na^＋、K^＋浓度及Osm也无明显变化。孕期尼古丁暴露的成年子代鼠脱水24h后,饮盐水量（2h内和24h内）明显增加,且其子代鼠脑组织AT1R和AT2R蛋白的表达量明显下降,与对照组比较均有明显差异（均P〈0.05）。结论孕期尼古丁可影响成年子代在脱水应激下的摄盐水平,且该变化可能与子代中枢血管紧张素受体表达下调有关。

Effects of Maternal Nicotine During Pregnancy on Water-electrolyte Metabolism in the Offspring Rats

Objective To determine the effect of perinatal exposure to nicotine on water-electrolyte metabolism related to renin-angiotensin system（ RAS） in the offspring rats. Methods Maternal rats during perinatal period were subcutaneously administrated with nicotine. The body weight,blood Na ＋ /K ＋ concentrations and plasma osmotic pressure of both the fetus and four-month old offspring were measured. Intake of the 1. 8% NaCl and water was measured following 24 h water deprivation in the adult offspring, and angiotensin receptors in the brain were determined. Results Fetal body weight was significantly decreased with the history variation of prenatal nicotine exposure,but there was no difference of blood Na ＋/K ＋ concentrations and plasma osmolality either in fetus or in adult offspring rats regardless of perinatal exposure to nicotine. To the offspring following perinatal exposure to nicotine,their salt appetite was significantly increased （ during the first 2 h and 24 h testing periods） by 24 h water deprivation. Furthermore, in the forebrain of the offspring with perinatal exposure to nicotine,expression of angiotensin AT1R and AT2R subtype was reduced. Conclusion The results showed that stimulated salt intake can be affected by exposure to nicotine in fetal origins,and the changed behavior （ water and salt intake） was associated with the remodeled expression of AT1 and AT2 receptors in the forebrain of the offspring.