Fig. 1.

Kidney function. a Glomerular filtration rate (GFR) based on the creatinine clearance over a 24-h period and adjusted for the body weight of the animal showed decline in renal function with ageing (6, 12 > 18 months of age, P < 0.01). Females had higher GFR than males (P < 0.05). b The plasma urea concentration was unaffected by either ageing or surgery although there was a tendency towards change in the concentration of urea with age after gonadectomy P = 0.068. c Albuminuria was higher in males vs. females (P < 0.01) and the amount of albumin excreted increased with age (6, 12 < 18 months of age, P = 0.01), though this effect was largely confined to males. d Proteinuria was higher in males vs. females (P < 0.001). Proteinuria also increased with age in males (6 < 12, 18 months of age, P < 0.05). The INTACT animals had higher proteinuria than the GONADX, and this was significantly reduced by castration (P < 0.001). Data are presented as mean ± SEM for n = 8 per group,*P < 0.05; **P < 0.01; ***P < 0.001