Research article
Diabetes-related renal growth and IGF-I accumulation in castrated rats

https://doi.org/10.1016/0168-8227(91)90048-IGet rights and content

Abstract

The effects of castration on diabetes-related renal growth and IGF-I regulation were studied. In the rat, prepubertal castration is associated with a normal or increased surge in plasma insulin-like growth factor I (IGF-I) at the time of ‘puberty’. In order to determine the role of sex steroids in the development of diabetes-related kidney growth and IGF-I regulation, Sprague-Dawley rats were castrated at the age of 4 weeks and streptozotocin diabetes was induced at the age of 13 weeks. The development of renal enlargement and kidney IGF-I levels was studied over the following 7 days. Kidney weight in diabetic animals was significantly greater than in controls, and by day 7, had increased by 27% (1.20 ± 0.03 vs 0.94 ± 0.03 g, P < 0.001). Kidney IGF-I content was significantly elevated in diabetic rats, peaking on day 1 (diabetic, 1159 ± 302 ng/g vs control, 237 ± 53 ng/g, P < 0.001) and remaining higher than control levels throughout the 7 days of the experiment. The pattern of diabetes-related kidney growth and IGF-I regulation in castrated rats resembles that of age matched intact postpubertal controls, suggesting that sex steroids do not have a direct role in these phenomena.

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  • This study was supported by grants from the National Health and Medical Research Council of Australia and the Austin Hospital Medical Research Foundation. L.A.B. is a National Health and Medical Research Council of Australia Medical Postgraduate Research Scholar.

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