Effects of Lead Nitrate on Liver Weight and Serum Total Cholesterol Amounts in Stroke-Prone Spontaneously Hypertensive and Wistar-Kyoto Rats

摘要

The administration of inorganic lead (Pb) ion to rats is well known to induce liver hyperplasia with liver enlargement and hypercholesterolemia. In the present study, the sensitivities of stroke-prone spontaneously hypertensive rat (SHRSP) and its normoten-sive control strain, Wistar-Kyoto rat (WKY), to these effects of Pb ion were estimated. Lead nitrate (LN) dissolved in a distillated water for injection was administered to male SHRSP and WKY by a single intravenous injection at a dose of 100mumol/kg body weight. In WKY, significant increases in the liver weight were observed at 24 and 48 hr after LN-administration, while in SHRSP, no such significant increases were observed up to 48 hr later. On the other hand, increased levels of serum total cholesterol after LN-administration were significantly higher in SHRSP than in WKY at each time, although the constitutive (control) level was the opposite. The present findings suggest that there is different susceptibility between SHRSP and WKY to LN-induced liver hyperplasia and hypercholesterolemia and further indicate that development of hypercholesterolemia is not necessarily correlated with that of liver hyperplasia.