[Changes of morphology and erectile function of the cavernous tissues in spontaneously hypertensive rats].

OBJECTIVE: To study the changes of morphology and erectile function of the cavernous tissues in spontaneously hypertensive rats. METHODS: Spontaneously hypertensive male rats (SHR) (n = 15) and normotensive Wistar-Kyoto rats (WKY) (n = 15) were studied for 20 weeks. Systolic blood pressure (SBP) was measured weekly by the tail/cuff method. Erectile function was tested by injecting apomorphine (APO). The expression alpha-smooth muscle actin (alpha-SMA) and collagen III was examined by immunohistochemistry. RESULTS: SHR showed a higher systolic blood pressure (205.7 +/- 11.9 vs 114.3 +/- 10.2 mm Hg) and a lower erection frequency (0.6 +/- 0.5 vs 2.4 +/- 0.6). The expression of alpha-smooth muscle actin and collagen III in the cavernous tissues in the SHR was significantly higher than in the WKY. CONCLUSION: The erectile function of the penis is markedly affected by hypertension, and the pathological changes may be one of the most important mechanisms of decreased erectile function in SHR.

[Growth hormone enhances regeneration of nNOS-containing nerve fibers in the aged rat penis].

OBJECTIVE: To investigate the effects of growth hormone (GH) on the erectile function and the number of neuronal nitric oxide synthase (nNOS) -containing nerve fibers in the penis of aged rats. METHODS: Twenty-four aged male SD rats (18 months) were randomized into 2 groups: GH intervention group and control group. After four and eight weeks, a half of each group were selected and tested for erectile function after apomorphine (APO) injection and then sacrificed for the detection of nNOS-containing nerve fibers in the penis by streptavidin-peroxidase conjugated method (SP method). RESULTS: After four weeks, the erectile function and the number of nNOS-containing nerve fibers showed no significant difference between the GH intervention group and the control group (P > 0.05). After eight weeks, the erection frequency was significantly different (P < 0.05) between the two groups, while the erection rate was not. The number of nNOS-containing nerve fibers in the GH intervention group was significantly larger than that in the control group (P < 0.01). CONCLUSION: GH enhances the regeneration of nNOS-containing nerve fibers in the penis and improves the erectile function of the aged rat.