Twisting of the spermatic cord: ischemia and reperfusion, toxicogenetic evaluation, and the effects of phosphatidylcholine in pre-clinical trials.

Phosphatidylcholine is the main phospholipid present in cell membranes and in lipoproteins, and can interfere with various biological processes. This lipid also has antioxidant activity, and protects against damage caused by free radicals under conditions of ischemia/reperfusion. Therefore, the present study was designed to evaluate toxicogenetic damage caused by twisting of the spermatic cord in ischemia/reperfusion, and whether phosphatidylcholine plays a role in conditions of ischemia/reperfusion in preclinical trials. The results indicate that spermatic cord torsion does not cause genotoxic damage or mutagenesis. A dose of 300 mg/kg of phosphatidylcholine is toxic and is thus not recommended. However, a dose of 150 mg/kg does not promote toxicogenetic damage, and though it does not statistically prevent tissue damage occurring from lack of oxygenation and nutrition of testicular cells, it has a tendency to reduce this damage. Therefore, this research suggests that further studies should be conducted to clarify this tendency and to provide a better explanation of the possible therapeutic effects of phosphatidylcholine in cytoprotection of germ cells affected by ischemia/reperfusion.

Expression and Subcellular Localization of Retinoic Acid Receptor-α (RARα) in Healthy and Varicocele Human Spermatozoa: Its Possible Regulatory Role in Capacitation and Survival.

Varicocele, an abnormal tortuosity and dilation of veins of the pampiniform plexus, is the most common identifiable and correctable cause of male infertility. It is now becoming apparent that signaling through vitamin A metabolites, such as all-trans retinoic acid (ATRA), is indispensable for spermatogenesis and disruption of retinoic acid receptor-α (RARα) function may result in male sterility and aberrant spermatogenesis. Herein, we investigated by Western blot and immunogold electron microscopy the expression profiles and subcellular localization of RARα in healthy and varicocele human sperm; in addition, we analyzed the effects of ATRA on cholesterol efflux and sperm survival utilizing enzymatic colorimetric CHOD-PAP method and Eosin Y technique, respectively. In varicocele samples, a strong reduction of RARα expression was observed. Immunogold labeling evidenced cellular location of RARα also confirming its reduced expression in "varicocele" samples. Sperm responsiveness to ATRA treatment was reduced in varicocele sperm. Our study showed that RARα is expressed in human sperm probably with a dual role in promoting both cholesterol efflux and survival. RARα might be involved in the pathogenesis of varicocele as its expression is reduced in pathologic samples. Thus, ATRA administration in procedures for artificial insemination or dietary vitamin A supplementation might represent a promising therapeutic approach for the management of male infertility.

Ascorbic acid supplementation restores defective leukocyte-endothelial interaction in alloxan-diabetic rats.

BACKGROUND: Defective leukocyte-endothelial interactions are observed in experimental diabetes and may reduce the capacity to mount an adequate inflammatory response. The present study investigated the effect of ascorbic acid, an inhibitor of free radical and glycated protein formation as well as an aldose reductase inhibitor, on leukocyte-endothelial interaction in alloxan-diabetic rats. METHODS: Rats were rendered diabetic by alloxan injection (40 mg/kg; iv). After 30 days, diabetic and nondiabetic controls were supplemented for 12 days with ascorbic acid (50 or 200 mg/kg/day) or received saline by gavage. The number of rollers, stickers after zymosan-activated plasma (10%) or leukotriene B(4) (1 microM) applied topically, and migrated cells after local injection of carrageenan (100 microg) were determined in the venules of the internal spermatic fascia by intravital microscopy. Erythrocyte velocity and wall shear rate were determined as well. Reactive oxygen species formation by endothelial cells was measured in vivo by the same technique. Immunocytochemistry for ICAM-1 detection on the endothelium of the venules of the internal spermatic fascia was carried out in cross sections of the whole testis of the animals. RESULTS: The reduced number of rollers, stickers and migrated cells, as well as the higher production of reactive oxygen species by endothelial cells in diabetic rats was corrected by ascorbic acid supplementation. The low immunoreactivity for ICAM-1 in the venules of diabetic rats was improved by ascorbic acid supplementation. Ascorbic acid supplementation did not interfere with erythrocyte velocity or wall shear stress. Ascorbic acid administered to control rats did not alter the parameters studied above. CONCLUSION: We conclude that ascorbic acid improves leukocyte-endothelial interaction in diabetic rats at least in part by restoring the expression of ICAM-1 in the venules of diabetic rats.