Studies On The Mechanism Of Damage Of Pituitary Gland Caused By Subchronic Cadmium Toxication In Chicken

In this paper, Hyline-white hens as experiment animals, we copied subchronic cadmiumtoxication model by added different dose cadmium in basic diet. Clinicalsymptom,anatomy, pathohistological changes in pituitary gland were observed; enzymaticactivity, anti-oxidative function,expression of apoptosis associated gene Fas and caspase-3mRNA and contents of related hormone were detected, for these we can deeply study themechanism of cadmium toxication on pituitary gland. The results showed as follows:1.The decrease of GSH-Px and SOD activities but the increse of MDA content caused bycadmium were confirmed.2. Cadmium could influence the ruction of Hypothalamus-Pituitary- target glandAxis,increase the contents of TSH,but decrease the contents of GH, E₂, P₄, FT₃, FT₄,disorderthe endocrine function.3. By detecting the enzymatic activity and enzymohistochemistry, it was first confirmed thatcadmium could influence the enzymatic activities of chicken pituitary gland,lead to the decreaseof SDH, ALP, Mg²⁺-ATPase, Ca²⁺-ATPase, G-6-Pase,but ACP activity increased,so thatcadmium could effect energy metabolism and damage organ in pituitary gland.4. By viewing the microstructure and ultrastructure in pituitary gland and TUNEL,it wascertificated that cadmium could damage mitochondria and endoplasmic reticulum and theninduce the apoptosis and necrosis of cells.5. The effect of cadmium on Fas and caspase-3 mRNA expression was detected bysemiquantitative RT-PCR. It revealed that cadmium can induce pituitary gland cell apoptosis bythe increase of Fas mRNA and caspase-3 mRNA expression.We systemly studied the subchornic cadmium toxication on hens' pituitary gland andapproached the mechanism of the endocrine toxication by cadmium from the cell,subcell andmolecule level, It will provide theoretical basis for research on environmental toxicology andpreventing and curing the cadmium poisoning, to enirch toxicology and comparative medicine, itis very significative to protect human or animals.