Abstract
1. In the present experiment, diethyl-paranitrophenyl-thiophosphate in emulsion was administered subcutaneously on rats twice per week in different doses of 24mg, 16mg, 8mg, 4mg and 2mg/kg. Then, histophathological investigations were made on the changes produced in the heart dividing the animals into three groups of acute, subacute and chronic stages by the length of their survival days.
2. In the acute stage, histologically, the granular degeneration of cardiac fibers was strong in the group administered of large doses and vice versa being nearly parallel to the amount administered, while vacuolar degeneration, swelling, homogenization, colliquative degeneration etc were strong in the groups received the administration of medium doses and mild in the groups of small doses without demonstrating parallel relationship between these changes and the amount administered.
3. In the subacute stage, all the changes like granular degeneration, swelling, vacuolar degeneration and colliquative changes nearly parallelled the amount administered except homogenization which was stronger in the groups received medium doses without demonstrating parallel relationship to the amount administered.
4. In the chronic stage, granular degeneration, vacuolar degeneration, colliquative degeneration etc were recognized only in the groups admistered of small doses demonstrating parallel relationship to the amount administered.
5. It was proved that on administration of Parathion over a prolonged period of time, the changes caused on the cardiac fibers by metabolic disturbances are characterized by the atrophy and homogenization of cardiac fibers, and in the interstitium, infiltration of round cells, proliferation of fibroblasts and argentaffine fibers, and calcification, and thus advance into fibrosis accompanied by tissue reactive reparation.
