Prevention of di(2-ethylhexyl)phthalate-induced testicular atrophy in rats by co-administration of the vitamin B12 derivative adenosylcobalamin.

The administration of 2g/kg of di(2-ethylhexyl)-phthalate (DEHP)-induced severe testicular atrophy coincident with the reduction of testicular specific lactate dehydrogenase (LDH-X) activity, zinc, magnesium, and potassium concentrations in rats. Co-administration of DEHP and adenosyl cobalamin (AdoCbl), one of the active vitamin B12s, prevented these testicular specific changes including fluctuations in testicular weight. On the other hand, co-administration of DEHP and methylcobalamin (MeCbl), the other active vitamin B12, did not prevent the testicular atrophy induced by DEHP under the present experimental conditions. In the liver, DEHP administration caused hypertrophy with changes in several metal concentrations and serum biochemical parameters. Co-administration of DEHP and AdoCbl or MeCbl did not prevent these hepatic changes, but aggravated hypolipidemia. The results demonstrated that the preventive effect of AdoCbl was a testicular specific action, and this effect may be stimulated solely by AdoCbl in vitamin B12 groups.