Effects of smoking on plasma testosterone level and erectile function in rats.

INTRODUCTION: There have been several conflicting reports of the effects of smoking on plasma testosterone levels and erectile function in clinical and animal studies. AIM: This study was conducted to determine the actual effects of smoking on plasma testosterone levels and erectile function in rat-smoking models. METHODS: For the exposure to cigarette smoke, the rats in a cage had a constant influx of smoke using a specially constructed device. Twenty-four Sprague Dawley (SD) rats for the acute cigarette exposure were allocated randomly into two groups: an experimental group and a control group. Thirty-six SD rats for the chronic cigarette smoke exposure were randomly divided into three groups: a control group and two experimental groups. MAIN OUTCOME MEASURES: After exposure to smoking, the rats were subjected to electrical field stimulation of the cavernosal nerve to assess the erectile function, and blood was collected to measure the levels of plasma thiocyanate, testosterone, luteinizing hormone, and follicle-stimulating hormone. The histological changes of testes and corpora cavernosum (CC) were examined. RESULTS: In the smoking groups, the thiocyanate levels were significantly higher than in the control group. Also, the mean arterial pressure (MAP) was significantly higher in the smoking groups, but the corpora cavernosal filling rate and maximal intracavernosal pressure/MAP were significantly lower than in the control group. The testosterone levels of experimental groups were significantly lower than those of control group, and the testosterone and thiocyanate levels were significantly correlated with erectile function components in chronic smoking groups. There was no significant histological change in the testes; however, in the CC, there was an increase in collagen fibers and decrease in smooth muscle and sinusoidal space in chronic smoking groups. CONCLUSION: The results suggest that both the vasoconstrictor effects of smoking and the decrease in testosterone levels after chronic smoking had some effects on erectile function in rats.

The effect of the partial obstruction site of the renal vein on testis and kidney in rats: is the traditional animal model suitable for varicocele research?

PURPOSE: We investigated the influence of the location of the partial renal vein obstruction on the left kidney, the bilateral testes, and cauda epididymal sperm quality and determined whether this animal model is suitable for varicocele study. MATERIALS AND METHODS: A total of 25 adult male Sprague-Dawley rats were assigned to three groups: group 1 (experimental varicocele by partial ligation medial to the internal spermatic vein for 8 weeks, n=8), group 2 (partial ligation lateral to the internal spermatic vein for 8 weeks, n=10), and group 3 (sham operation for 8 weeks, n=7). Rats in groups 1, 2, and 3 underwent a left nephrectomy and bilateral orchiectomy at 8 weeks after the operation. Histological changes and Johnsen score in both testes were analyzed. Fibrotic changes in the left kidney were assessed by quantitative image analysis. Numbers of sperm and proportions of motile sperm in the cauda epididymides were determined. RESULTS: Significant histological abnormalities and Johnsen score changes were observed in the testes in group 1. Renal fibrosis did not differ significantly among the groups. The proportions of motile sperm were significantly lower bilaterally in group 1 than in groups 2 and 3. However, the mean bilateral epididymal sperm count in group 1 was not significantly lower than in groups 2 and 3. CONCLUSIONS: Our results showed that experimental varicocele in the rat, induced by partial ligation medial to the internal spermatic vein, influences epididymal sperm quality without harmful effects on the left kidney. The present study certifies that this traditional animal model is suitable for varicocele research.