OVARIECTOMY ATTENUATES PROTEINURIA AND GLOMERULAR INJURY IN UNILATERALLY NEPHRECTOMIZED FEMALE SPRAGUE-DAWLEY RATS

To determine the contribution oft:he ovary to the development of glome rulosclerosis, we investigated the effect of ovariectomy on glomerulos clerosis, using the unilaterally nephrectomized (Nx) female Sprague-Da wley rat. At 6 weeks of age, groups 2 and 3 underwent unilateral right nephrectomy and group 3 was simultaneously ovariectomized, while grou p 1 underwent a sham operation. Body weight, blood pressure, urinary p rotein, serum albumin, cholesterol, blood urea nitrogen and serum crea tinine were checked every 2 months from 2 to 12 months after right nep hrectomy. Control group 1, the Nx group 2 and the ovariectomized (Nx ovariectomized) group 3 were studied morphologically at 6 and 12 mont hs after nephrectomy. Body weight significantly increased in ovariecto mized rats as compared with control and Nx rats. Nx rats became protei nuric with age. Ovariectomy significantly reduced proteinuria to the s ame levels in the controls. The glomerulosclerosis index was significa ntly higher in Nx rats than in either controls or ovariectomized rats. Ovariectomy attenuated glomerular injury in Nx rats, though not to th e same levels in the control rats. Three groups showed no significant differences in either blood pressure or plasma somatomedin C. Growth h ormone (GH) was significantly decreased by ovariectomy. The severity o f glomerular injury and the glomerular tuft volume correlated with GH levels. Our results suggested that a decrease in plasma GH may contrib ute to the attenuating effect of ovariectomy on the development of glo merular injury in aging unilaterally Nx female Sprague-Dawley rats.