A B S T R A C T Experiments were designed to study whether or not the mechanism of handling dietary cholesterol in adulthood can be modulated by the manipulation of cholesterol homeostasis during neonatal period. (b) no alteration in the fecal excretion of steroids, or (c) no alteration in the cholesterol 7a-hydroxylase activity when they were challenged with a high cholesterol diet. Early weaning did not influence the fecal excretion of steroids or cholesterol 7a-hydroxylase activity but resulted in a slight decrease in the hepatic 3-hydroxy-3-methylglutaryl-CoA reductase activity when they were challenged with a high cholesterol diet.These results suiggest that stimtulation of cholesterol catabolism rather than cholesterol feeding or early weaning during neonatal period can influence the response to dietary cholesterol challenge in adulthood.A preliminary report of this work has been published (1).

ABSTRACT. We investigated the expression characteristics of matrix metalloproteinases (MMP)-2 and MMP-9 in the ovaries of normal adult guinea pigs during the estrous cycle. The estrous cycle was classified according to the appearance of the vaginal orifice and by vaginal exfoliated cell smears. Guinea pigs that had experienced at least two normal estrous cycles were selected. Ovaries were collected from guinea pigs at proestrus or metestrus (N = 6). The expression characteristics of steroidogenic acute regulatory protein (StAR), MMP-2, and MMP-9 were investigated by hematoxylin and eosin staining and immunohistochemical staining. The results showed that MMP-2, MMP-9, and StAR were significantly expressed in the granulosa and thecal cells of the ovarian atretic follicles during proestrus, and were strongly expressed in the corpus luteum during metestrus.