Free amino acids of testes. Concentrations of free amino acids in the testes of several species and the precursors of glutamate and glutamine in rat testes in vivo

Abstract

Determination of the free amino acid and lactate content of testicular tissue in rat, guinea pig, rabbit, cat, gerbil, hamster, chicken and bullfrog indicates a substantial species variation. Insulin hypoglycaemia and ammonium acetate toxicity changes the concentration of several free amino acids of rat testes. (14)C radioactivity from labelled acetate and ethanol is rapidly incorporated into some of the free amino acids of rat testes in vivo, whereas incorporation from [(14)C]glucose is relatively slow. These results have been compared with those obtained from similar studies with rat brain. In contrast to brain, there is no evidence for glutamate compartmentation in testes.

Testosterone-induced changes in testicular antioxidant system

“…Testis of adult rats and mice are reported to be rich in GSH (Mushawar & Koeppe, 1973;Grosshans & Calvin, 1985). Testis of adult rats and mice are reported to be rich in GSH (Mushawar & Koeppe, 1973;Grosshans & Calvin, 1985).…”

“…To our surprise, free -SH group and ascorbic acid levels in the testis were increased following T P treatment. Testis of adult rats and mice are reported to be rich in GSH (Mushawar & Koeppe, 1973;Grosshans & Calvin, 1985). GSH is considered to play an important role in the proliferation and differentiation of spermatogenic cells and provide protection to germ cells against harmful effects of free radicals (Teaf et al, 1985).…”

Glutathione S-transferase expression in the human testis and testicular germ cell neoplasia

“…Sertoli cells are largely responsible for germ cell oxido-reductive enzyme systems (Voganathan et al, 1989a) and glutathione production (Li et al, 1989). Testes of mature rodents contain high concentrations of GSH (Mushawar & Koeppe, 1973) and increase in testicular GSH parallels spermatogenic cell development (Grosshans & Calvin, 1985). GSH protects against germ cell mutagenesis by ethyl methanesulfonate in the F-344 rat and this is dependent on enzymatic conjugation by GST (Teaf et al, 1985).…”

Expression of multiple glutamate transporter splice variants in the rodent testis

“…1,2 However, much remains to be determined as to the mechanisms by which glutamate, which is abundant in the testis 1, [3][4][5] and testicular fluids, 6 might be compartmentalized in the mammalian testis. Glutamate does not penetrate the blood-testis barrier, 2 but does appear to be synthesized locally.…”