組織生理学的にみた甲状腺機能低下症が羽毛の発達におよぼす影響

抄録

Histoenzymological profiles have been studied of the feather-forming tissues in the Blue Rock Pigeon (Columba livia) under functional athyroidism induced by thiouracil feeding. Feathers were plucked from the ventrum covering the pectoral and abdominal tracts. In control birds, as well as those under replacement therapy, new feathers emerged outside the follicles on the 7th day after such plucking and were fully formed by the 30th day. In the experimental birds, these two phases of feather development were delayed and seen on the 25th and 60th days respectively.
Activities of alkaline and acid phosphatases; glucose-6-phosphate, succinate, malate and lactate dehydrogenases (G-6-PDH: SDH; MDH & LDH) during various stages of feather development in the birds under the three different conditions were also evaluated histochemically. Acid phosphatase and LDH activities were not affected adversely by athyroidism, but those of alkaline phosphatase, G-6-PDH, SDH and MDH, all recognised as essential for supporting normal development of feathers, were significantly reduced.
It is suggested that athyroidism retards feather development through adverse metabolic effects exerted as a result of decreased activities in a number of key enzymes.