Changes of mitochondria calcium and cytochrome C in epididymis associated with apoptosis in varicocele rats / 中国组织工程研究

BACKGROUND: Varicocele (VC) can induce the infertility in males, so the investigation on its mechanism is important for the treatment of male infertility. OBJECTIVE: To analyze the effects of VC induced by surgical operation on the contents of mitochondria calcium, cytochrome C and cell apoptosis as well as the changes of microstructure and ultrastructure in epididymis. DESIGN: Randomized control experiment. MATERIALS: The experiment was conducted in Jiamusi University between June 2003 and May 2004. Forty male adolescent Wistar rats with the average body mass of (220±20) g were selected, which were provided by the Animal Laboratory of Jiamusi University. Rats were randomly divided into sham-operation group and deligation group with 20 rats in each group at one week after feeding at room temperature. METHODS: Rats in the sham-operation group were made into sham-op eration models by exposing the left renal vein. Rats in the deligation group were deligated of partial left renal veins so as to establish VC models. Bilateral epididymides were removed at ten weeks after operation. The levels of mitochondria calcium in head and body of epididymis as well as the contents of cytochrome C and cytoplasm cytochrome C were detected. The cell apoptosis was detected by in situ terminal deoxynucleotityl transferase mediated dTUP nick end labeling (TUNEL) technique. The specimens of corpus epididymis were routinely made for observation under optimal microscope and electron microscope. The changes of microstructure and ultrastructure of epididymis were studied.MAIN OUTCOME MEASURES: The contents of mitochondria calcium, cytochrome C and cytoplasm cytochrome C. Cell apoptosis. Changes of cellular morphous in epididymis. RESULTS: A total of 40 rats were involved in the analysis of results.① The contents of mitochondria calcium in bilateral epididymis were obviously decreased in the deligation group than the sham-operation group [(4.72±1.45), (5.90±1.97), (10.13±2.34) mg/g, (P ＜ 0.01)].②The content of mitochondria cytochrome C in right epididymis obviously increased more in the deligation group than the sham-operation group [(0.36±0.20), (0.19±0.14), (0.15±0.07) μmol/L (P ＜ 0.05)]. ③The contents of cytoplasm cytochrome C in bilateral epididymis greatly increased more in the deligation group than the sham-operation group [(8.17±1.49), (7.48 ± 1.60), (5.93±1.60) mol/L, (P ＜ 0.05)].④The apoptotic rate of bilateral cells in the deligation group was significantly increased than the sham-op eration group [( 13.3±1.9)%, ( 12.6±1.5)%, (6.2±0.3)%,(P ＜ 0.01 )]. However, there were no significant differences in mitochondria calcium, cytochrome C, cytoplasm cytochrome C and apoptotic rate between the left and right mitochondria of the deligation group (P ＞ 0.05).⑤Main changes under light microscope: cuctus epididymis shrinked, the blebbing appeared in epithelial cells, and the light cells as well as halo cells in epithelia were significantly increased. ⑥Main representation under electron microscope: the cytolysosome inside the chief cells were increased and enlarged with increased residual bodies, and the endoplasmic reticulum expanded, the mitochondria cristae was dim, the Golgi complex was vacuolated. Besides, nuclear chromatin were dense and in lump at different size, which located mainly in the nuclear membrane. The microvilli of columnar epithelial cells were sparse and local defects could be seen. CONCLUSION: The cytochrome C is released to kytoplasm via mitochondrial outer membrane, which activates the caspase 3 and leads to the apoptosis, and accordingly causes excessive apoptosis of epididymal tissues and as well as the changes of microstructure and ultrastructure. All these changes may be one of the important reasons of infertility resulting from VC.

Effect of aging on the endothelial function of the penile corpus cavernosum in rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of aging on the endothelial function of the penile corpus cavernosum in rats.</p><p><b>METHODS</b>The intracavernosal pressure (ICP) was compared in response to acetylcholine (Ach, endothelium-dependent vasodilator), sodium nitroprusside (SNP, an NO donor) and A23187 (a calcium ionophore)in the young (5 months old) and aged (20 months old) rats. In addition, the activity of nitric oxide synthase (NOS)in penile cavernosal tissues was examined.</p><p><b>RESULTS</b>Ach-mediated ICP was significantly attenuated from the maximum of (54.8 +/- 4.2) in the young rats to (40.3 +/- 2.8) mm Hg in the aged ones (Ach = 0.1 mmol/L), P < 0.01. The ICP to SNP (0.1 mmol/L) was (58.9 +/- 4.7) mm Hg in the young rats and (51.7 +/- 5.3) mm Hg in the aged. No statistically significant difference was noted between the two groups, P > 0.05. The Ach-mediated ICP in the young rats was not significantly augmented from the maximum of (54.8 +/- 4.2) to (55.8 +/- 4.7) mm Hg in the presence of the calcium ionophore A23187 (10 micromol/L), P > 0.05. However, A23187 significantly augmented Ach-mediated ICP in the aged from the maximum of (40.3 +/- 2.8) to (56.2 +/- 4.1) mm Hg, P < 0.01. Finally the activity of nitric oxide synthase was not significantly attenuated in either the aged or the young, P > 0.05.</p><p><b>CONCLUSION</b>The endothelial function of the penile cavernosum declines with the advance of age. And endothelial dysfunction may play some role in the mechanisms of age-related erectile dysfunction.</p>

Study of varicocele and oxidative stress / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the mischief mechanism of oxidative stress in the varicocele (VC).</p><p><b>METHODS</b>Serum was taken from the spermatic and peripheral veins on ligation of the internal spermatic veins in 28 infertile males with VC. Experimental VC was established in male rats by partial ligation of the left renal vein. And testis tissue was taken three months after operation. The nitric oxide(NO), nitric oxide synthetase (NOS), xanthine oxidase (XO), lactic acid(Lac) and lactic dehydrogenase (LDH) in the serum of 28 infertile males with VC and the testis tissue of the VC rats were detected by spectrophotometry.</p><p><b>RESULTS</b>NO, NOS, XO and Lac in the serum of internal spermatic veins in the infertile males with VC were significantly higher than in the serum of peripheral veins in the VC patients (P < 0.01, P < 0.05). LDH was lower than that in peripheral serum. NO and XO of the left testis tissue in the VC rats were higher compared with the control group (P < 0.01). Lac in the left testis of the VC rats was lower than that in the control group rats (P < 0.01).</p><p><b>CONCLUSION</b>NO, NOS and XO in the serum of the VC patients and in the testis tissues of the VC rats were increased, and Lac and LDH were changed obviously, which might not only disturb spermatogenesis, but also inhibit sperm motility. Therefore they might be one of the causes of infertility in VC patients.</p>

Study on the mitochondria Ca 2+, expression of Bcl-2 and Bax and germ cell apoptosis in testes of rats with varicocele / 中国病理生理杂志

AIM: The cytoplasm Ca 2+, expression of Bcl-2 and Bax and germ cell apoptosis of testes in adult male rats with varicocele were observed to investigate the relationship between apoptosis and infertility. METHODS: Thirty-five healthy male Wistar rats were divided into two groups randomly: varicocele group (VG, n=20) and sham operation group (SOG, n=15). Bilateral testes were removed after ten weeks. One part of it was homogenized, the other part was performed for tissue sectioning. The atomic absorption method was used to detect the cytoplasm Ca 2+. The germ cell apoptosis was detected by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) technique. The expression of Bcl-2/Bax was detected by immunohistochemical method. RESULTS: The cytoplasm Ca 2+ in testes of rats with varicocele was decreased obviously. The apoptosis indexes of germ cells and Bax expression in VG were significantly increased as compared with those in the SOG, while Bcl-2 expression was obviously decreased. CONCLUSION: The results showed that apoptosis was increased in testes of VG rats, suggesting that male infertility with varicocele may be caused by some apoptosis agents such as high temperature, testes toxin and oxygen free radical. The cytoplasm Ca 2+ and change of expression of Bcl-2/Bax may contribute to germ cell apoptosis and cause male infertility.