Effect of thyroid hormone on the contents of NOS and CO in the penile corpus cavernosum of rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To determine the contents of NOS and endogenous CO in the penile corpus cavernosum of Wistar rat models of hyperthyroid and hypothyroid, to detect the effects of thyroid hormone and endogenous CO on rat penile erection, and to further investigate the influence of thyroid hormone on human penile erection.</p><p><b>METHODS</b>Fifty 3-month-old male Wistar rats were randomly and equally divided into 5 groups: a hyperthyroid, a hyperthyroid treatment, a hypothyroid, a hypothyroid treatment and a control group. The contents of NOS and CO were detected by ultraviolet spectrophotometry.</p><p><b>RESULTS</b>Compared with the controls, the content of NOS was significantly decreased in both the hyperthyroid and the hypothyroid groups (P < 0.01), even lower in the latter than in the former (P < 0.01), and so was the content of CO (P < 0.01), lower in the former than in the latter (P < 0.01). After treatment, the levels of NOS and CO were both elevated in either the hyperthyroid or the hypothyroid group, with no significant difference from that of the controls (P > 0.05).</p><p><b>CONCLUSION</b>The contents of NOS and CO in the penile corpus cavernosum decrease with the imbalance of thyroid hormones, but return to normal once the imbalance is corrected. Under the same conditions, hypothyroid inflicts more damage on penile erection than hyperthyroid.</p>

Nitric oxide synthetase and carbon monoxide decrease in the penile corpus cavernous of hyper homocysteine rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To detect the levels of nitric oxide synthetase (NOS) and carbon monoxide (CO) in the penile corpus cavernous of adult male Wistar rats with high homocysteine (Hhcy) and to explore the relationship of NOS and CO levels with erectile dysfunction.</p><p><b>METHODS</b>Twenty Wistar rats were equally and randomly divided into a control and an Hhcy group and fed on normal diet and normal diet with 3.0% methionine respectively. Four weeks later, the levels of NOS and CO in the penile corpus cavernous were detected by ultraviolet spectrophotometry and that of serum homocysteine by the cycle enzyme method.</p><p><b>RESULTS</b>Compared with the control group, the levels of NOS and CO in the penile corpus cavernous were significantly lower in the Hhcy group, (6.45 +/- 1.12) nmol/(g x min) vs (10.77 +/- 0.60) nmol/(g x min) and (10.60 +/- 0.92) micromol/L vs (13.36 +/- 0.44) micromol/L, while that of homocysteine was significantly higher, (22.32 +/- 1.65) micromol/L) vs (4.90 +/- 1.73) micromol/L.</p><p><b>CONCLUSION</b>Four-week diet with methionine can cause Hhcy and significantly decreased levels of NOS and CO in the penile corpus cavernous in Wistar rats. Hhcy is an independent risk factor of erectile dysfunction.</p>