Studies on the testicular effects and zinc excretion produced by various isomers of monobutyl-o-phthalate in the rat.

Mono-n-butyl, -iso-butyl, -sec-butyl or -tert-butyl esters of o-phthalic acid were orally administered at 800 mg/kg body wt./day for 6 days, to young male rats. All of the animals except those treated with the mono-tert-ester developed marked testicular atrophy. Additionally, only those isomers producing testicular damage were found to alter zinc metabolism by increasing the urinary excretion of zinc and by depleting the concentration of this element in testicular tissues.