The effects of melatonin and the antioxidant defence system on apoptosis regulator proteins (Bax and Bcl-2) in experimentally induced varicocele

Abstract

Our aim was to examine the effects of melatonin on the testicular tissue of adult rats with experimentally-induced left varicocele, and to determine the relationship between melatonin and apoptosis regular proteins in the anti-oxidant defence system. Forty adult male Wistar rats were divided equally into four groups. A sham operation was performed on the rats in group I, and experimental left varicocele was created in groups II, III and IV. Melatonin was administered intraperitoneally at doses of 5 mg/kg and 10 mg/kg to rats in groups III and IV, respectively. An immunohistochemical analysis of the left testicular tissue was performed to evaluate the expression of Bax and Bcl-2, while tissue malondialdehyde (MDA) and antioxidant enzyme activities were assessed in homogenates to determine the role of the oxygen defence system. The immunohistochemical analysis revealed an increased ratio of pro-apoptotic protein Bax in groups II and III, whereas no significant activity was observed in the sham operated rats ( P<0.05). Similarly, the tissue MDA level increased and a significantly decreased level of antioxidant enzymes was observed in these groups ( P<0.05). Although rats in group IV showed a slightly increased ratio of the pro-apoptotic marker Bax, there was no significant difference between groups I and IV. Similarly, group IV showed decreased levels of MDA and increased levels of anti-oxidant enzyme activity with decreased Bax expression. The close relationship between pro-apoptotic/anti-apoptotic markers, reactive oxygen species and antioxidant agents provided a useful in vivo model for studying the pathophysiology of varicocele and evaluating the role of antioxidants in the prevention testicular damage.

The role of heat shock protein 70 (Hsp 70) in male infertility: is it a line of defense against sperm DNA fragmentation?

“…The Western blot picture of a-tubulin is representative blots from random patients in the study. apoptosis is related to male factor infertility (2,8,39,40). In the present study, we also demonstrated significant inverse correlations between the percentage of TUNEL-positive cells and both sperm concentration and motility.…”

The Hypoxic Testicle: Physiology and Pathophysiology

“…p53, a master gene in apoptosis and a target of p38 MAPK (Figure 2), is activated in rats with experimental varicocele [156]. In fact, the proapoptotic gene Bax, which is a transcriptional target of p53, is upregulated in experimental varicocele in animal models [47, 157–159]. In addition, the downregulation of Bcl-2 and increased expression of caspase-9 and activated caspase-3 in the ipsilateral testis at eight and 12 weeks after the onset of varicocele has been documented, indicating gradually increased testicular tissue apoptosis through the intrinsic pathway [158].…”

Varicocele and Male Infertility: Current Issues in Management-A Review

“…These may be elevated in isolation in spermatic vein with normal peripheral levels. Turkyilmaz et al [35] in a study comparing adolescents with and without varicoceles, spermatic vein levels of nitric oxide were significantly higher in adolescents with varicoceles. Genetic and lifestyle factors may predispose patients to more severe damage from a varicocele.…”