Effects of chlorpyrifos on ultimobranchial and parathyroid glands of Indian skipper frog, Euphlyctis cyanophlyctis

This study investigated effects of chlorpyrifos on ultimobranchial (UBG) and parathyroid glands (PTG) of frog, Euphlyctis cyanophlyctis. Frogs were treated with chlorpyrifos for short and long term and sacrificed after 24, 48, 72 or 96 h in short term and after 5.10, 15 and 30 days in long term. Chlorpyrifos exposure provokes   decrease  in    serum  calcium  levels  after  48 h which persists till 96 h. There is slight decrease in the nuclear volume of UBG cells and  cytoplasm depict weak staining response after 72 h. After 96 h these changes are more pronounced. PTG of Euphlyctis cyanophlyctis exposed to chlorpyrifos exhibit no change till 96 h. Serum calcium decreases on day 10 after chlorpyrifos exposure which continue to fall progressively till 30 days. After 15 days chloryrifos exposure, nuclear volume of UBG exhibit decrease and follicular epithelium displays decrease in height. Follicular epithelium after 30 days chlorpyrifos exposure reduces to the extent that it becomes single layered. Few degenerating cells have been discerned. At this interval nuclear volume of ultimobranchial cells exhibits a further decrease. PTG of chlorpyrifos treated frog depicts increased nuclear volume of PTG at 10 and 15 days. The nuclei of PTG are hyperchromatic and the gland becomes compact at 15 days. After 30 days following chlorpyrifos treatment nuclear volume exhibits further increase. Also degenerating cells make their appearance. Calcium regulating glands UBG and PTG of frogs were adversely affected by exposure to chlorpyrifos which may disturb the physiological functions of the organism. DOI: http://dx.doi.org/10.5281/zenodo.4004156