醋酸铅对大鼠血压、心肌细胞膜Na泵及Ca泵活性的影响

Effects of Lead Acetate on Blood Pressure, Na￣+, K￣+-ATPase and Ca￣(++)-ATPase Activities in Myocardial Microaome of Rats

对雄性ＳＤ大鼠用醋酸铅（ＰｂＡｃ）５０００ｍｇ／ｋｇ急性灌胃，对血压无影响，而致心肌细胞膜Ｎａ泵活性下降，Ｃａ泵活性升高，尿肌酐降低，肾肿大。实验表明大鼠每天染毒１０、３０、９０ｍｇ／ｋｇＰｂＡｃ９周，呈剂量－潜伏期和剂量－效应关系，使ＳＢＰ升高。各染毒组４～９周ＳＢＰ稳定上升，血铅、尿铅和心肌细胞膜Ｃａ泵活性、胸主动脉Ｃａ含量增高，心肌细胞膜Ｎａ泵活性降低，但对ＤＢＰ、肾重和尿肌酐含量无影响。提示低铅使心肌细胞膜Ｎａ泵活性降低，ＳＢＰ升高在早期铅中毒性心血管毒作用中具有重要意义。

Acute effects of lead on the blood pressure(BP), Na+,K+-ATPase and Ca++-ATPase activities were studied in male SD rats o. p. (oral prepared )with single dose of lead acetate (PbAc) at 5000/kg(n = 8 ). The results showed that no effect on BP was observed. however, decline of urinecreatinine levels, Na+, K+-ATPase activity and elevation of Ca++-ATPase activity in the myocardial microsome swollen kidney were clearly found. Subchronic effects were also investigated in rats,o. p. with repeated doses of 10, 30 and 90 mg/kg. day, respectively,for 9 weeks. The systolic BP(SBP)was found going up from 3 day of lead administration in two higher dosed groups of 30 and 90 mg/kg. day and from the second week in the lower dosed group. A persistent elevation of SBP was observed in a dose-related and time-related manner at the following 4～9 weeks in all groups. Meanwhile. levels of blood and urinary lead,and calcium content in the tissue of thoracic aorta and Ca++-ATPase activity in myocardial microsome were increased, but Na+,K+-ATPase activity in the myocardial microsome was found dereased. However, the diastolic BP(DBP),kidney weight and urinecreatinine levels had no obvious influence. The dtudy demonstrated that lead can influence the activity of enzyme in the myocardial cellular membrane,elevation of SBP were observed in the lower doses PbAc.