Evaluation of Testicular Responsiveness to Ingestion of Methyl Parathion in Roseringed Parakeets (Psittacula krameri Neumann)

Oral administration of methyl parathion at very low levels caused decrease in the paired weight,’ acetylcholinesterase enzyme activity, seminiferous tubular diameter and the number of healthy germ cell containing tubules in the testes of adult roseringed parakeets in a dose and duration dependent manner, but did not influence cytomorpholgy and nuclear diameter of Leydig cells in the testes of any birds. A statistically significant negative correlation between the enzyme activity and the number of degenerated germ cell containing tubules in the testes of methyl parathion fed birds may be an indication that the antigonadal influences of given pesticide may be of pharmacological origin.