Flow Cytometric Evaluation of Sperm Superoxide Anion Production in Rats With Experimental Varicocele

Abstract

To determine whether intracellular superoxide anion production changes in the sperm of rats with experimental varicocele and to study mitochondrial membrane potential (MMP), sperm viability, antioxidant activity, Bax and Bcl-2 changes, and sperm count and motility in these rats. The study groups consisted of 32 male rats divided into the following 4 groups: control, sham, varicocele-1, and varicocele-2. Experimental varicocele was established by partial ligation of the left renal vein in the latter 2 groups. Animals were killed 2 and 6 months after surgery, and dilation of the internal spermatic veins was observed. Then, superoxide anion production, MMP, antioxidant activity, and sperm characteristics were evaluated. Flow cytometry was used to study sperm superoxide anion production, assessed by dihydroethidium and MMP with rhodamine 123. Our results showed intracellular superoxide anion production significantly increased, and MMP, sperm viability, sperm count, and motility decreased in rats with experimental left varicocele. More Bax-positive cells were seen in the varicocele groups. However, there was no significant difference for seminal plasma antioxidant activity among all groups. These findings suggest that a main source of reactive oxygen species production in varicocele condition is intracellular.