Effect of phenobarbital on the induction of glutathione S-transferases in rat testis

Abstract

Glutathione S-transferases are a family of multifunctional proteins involved in intracellular transport processes and drug detoxication. In rats, these enzymes are dimeric proteins, and exist as cytosolic and microsomal proteins. The affinity purified rat testicular glutathione S-transferases are comprised of four subunits, Yc of α class, Yb and Yβ of μ class and Yδ of π class. On chromatofocusing, they were resolved into six anionic and four cationic isozymes. The cationic isozymes were found to be abundant. All these isozymes on electrophoresis were found to contain heteromers except for two isozymes. The expression of individual subunits and their activity was elevated on treatment with multiple doses of phenobarbital in rat testis. Among all of these, according to the immunological studies, Yδ, a π class glutathione S-transferase, was induced predominantly in response to phenobarbital.