R. G. Brown

Collagen levels in tissues from selenium deficient ducks

1. Nutritional myopathy was produced in ducks by feeding the birds selenium deficient diets. The myopathy increased in severity the longer the ducks were fed the selenium deficient diet. 2. There was less total collagen and lesser amounts of soluble collagen found in the tendons of ducks fed the selenium-deficient diet. Likewise, the collagen fibrils were of decreased diameter in those birds. 3. The fibroblasts present in the tendons of the deficient ducks were degenerate. It appears the selenium deficiency produced damaged fibroblast membranes which resulted in decreased collagen synthesis. The resultant loss of collagen structure could have produced a functional tendotomy which caused myodegeneration.

The ovulation-inducing activity of highly purified ACTH in the hen (Gallus domesticus)

Abstract 1. 1. Adrenocorticotrophic hormone (ACTH) from a variety of sources was injected into laying hens within 2 hr after the last oviposition of the sequence. 2. 2. The purity of the preparations was assessed by chromatography on Sephadex G-50 and isoelectric focusing. 3. 3. Pure ACTH induced ovulation at doses between 6.25 iu/hen and 100 iu/hen. The median effective dose (ED50) was 7.54 iu/hen.