Effect of experimental varicocele on the expressions of notch 1, 2, and 3 in rat testes: an immunohistochemical study

Objective: To study expressions of Notch receptor isoforms (Notch 1, 2, and 3) in normal and varicocele-induced rat testes to examine their possible functions in cell fate. Design: Comparative and controlled study. Setting: Animal Care and Operation Unit, Akdeniz University. Animal(s): Wistar male rats for experimental and control groups. Intervention(s): The control group underwent a sham operation (n = 6). The experimental groups underwent partial ligation of the renal vein to induce an experimental varicocele and then were killed 9 (n = 6), 11 (n = 6), and 13 (n = 6) weeks after the induction of varicocele. Main Outcome Measure(s): All tissues were fixed and routinely processed for paraffin embedding. Subsequent immunohistochemical studies were performed. Result(s): In the sham-operation rat testes, Leydig cells and elongated spermatids were immunopositive for Notch 1, Notch-2 expression was present in Leydig cells, spermatogonia, and primary spermatocytes. Notch-3 expression was limited to Leydig cells. Varicocele formation diminished the expression of both Notch-1 and Notch-2 receptors as the varicocele formation progressed over time. Conclusion(s): The present study suggests that Notch 1 is related to the maturation of spermatids. Notch 2 is related to both proliferation and maturation of spermatogenic cells, whereas Notch 3 seems to be related to Leydig cell functions. The decrease of both Notch-1 and Notch-2 expression depended on the degree of varicocele development over time, indicating a potential role in varicocele-associated testicular dysfunction. (C)2005 by American Society for Reproductive Medicine.