Basic scienceAndrogen, estrogen, and progesterone receptor gene regulation during diabetic erectile dysfunction and insulin treatment
Section snippets
Animals
Male Sprague-Dawley rats aged 6 months (weight range 440 to 560 g) were purchased from Charles River Laboratories (Wilmington, Mass). The rats were divided into three groups. Group 1 (n = 20) served as the nondiabetic control group. In groups 2 (n = 20) and 3 (n = 20), diabetes was induced by two intraperitoneal STZ injections (40 mg/kg) in citrate phosphate buffer (0.1 M citric acid and 0.2 M disodium phosphate, pH 7.0) at a 1-week interval. The development of diabetes was confirmed by blood
Results
The diabetic rats showed significantly lower body weight than the controls. The HbA1 level was high in the diabetic rats but lowered significantly after insulin treatment. The blood glucose levels were significantly greater in the 4-week and 8-week diabetic rats than in the 4-week and 8-week control rats, respectively. The 4-week and 8-week insulin-treated diabetic rats showed statistically significant lower blood glucose levels than did the diabetic rats, respectively.
Comment
We investigated the effect of short-term diabetes and insulin treatment on erectile function using the STZ-induced diabetic rat model, with special reference to the alteration of SHR expression in the smooth muscle cells of the rat crura.
Alterations in ICP and the latency period have been used as in vivo indexes of the impaired neurovascular elements of penile erectile function.14 In this study, a statistically significant reduction in the ICP with a prolonged latency period was observed in the
Conclusions
To our knowledge, this is the first study to demonstrate that insulin treatment may restore erectile function through restoration of SHR gene and protein expression in the diabetic rat crura.
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This research was supported by National Institutes of Health grants RO1DK055040 and RO1AG016870.