The present experiment was designed to study the relationship of the parathyroid gland to the calcium metabolism in the laying hen. The changes of the egg production, egg shell characters and of the serum calcium concentration at various times after parathyroidectomy were observed. The results obtained are as follows : 1) Hens continue to lay eggs, but the rate of egg-laying decreases considerably, and abnormalities or malformations of the egg are observed especially soon after operation. 2) Egg weight, egg shell weight, per cent shell weight and egg thickness decreases slightly as the effect of operation, but each of difference is not significant statistically. 3) The serum calcium concentration decreases significantly by removal of parathyroid gland, and reaches a minimum on the 2nd day after operation, thereafter it increases gradually but do not returns to normal level on the 18th day. According to the results, it may be assumed that the parathyroid gland plays an important role in the mobilization of calcium, and thus, indirectly influences shell formation in the laying hen.
上皮小体がCa代謝に関与し,鶏においても血清Ca量の変動に重要な役割を果していることは古くから知られているところであるが,その支配機構は未だ充分には知られていない.これらの研究は上皮小体の機能が解明されるにしたがつて急速の進展を示してきた.Tilgner-Peter(1957)は去勢鶏の上皮小体を除去し,Campbell and Turner(1942),Fleishman and Fried(1945)およびPolin and Sturkie(1958)はestrogenを注射し,またMacowan(1931),Avcryetal.(1940)およびPolinetal.(1957)は上皮小体抽出物parathortnoncを注射して,それぞれその後の血清Ca量の変動を観察することにより,上皮小体の機能を論じている.しかし上皮小体と卵形成との関係については現在までSun and Macowan(1930),Polinetal.(1957)等の報告があるにすぎない. 木研究は産卵鶏の卵形成に対する上皮小体の役割を検討するため,産卵鶏の上皮小体を除去し,その後の産卵状況ならびに卵殻の形成状態を調べ,あわせて除去前・除去後の血清Ca量の変動を経時的に観察し,上皮小体とCa代謝との関連性を究明したものである.
Mendeley出力
