Effects of steroids with different endocrine profiles on the development, morphology and function of the bursa of Fabricius in chickens.
This paper describes the effect of various steroids on the anlage of the bursa of Fabricius in chickens. The steroids were administered by dipping embryonated eggs on the third day of incubation in ethanolic solutions of these steroids. The results with about 30 different steroids show that the capacity to inhibit the development of the bursa does not correlate with the endocrine properties of these steroids as measured in routine screening tests for androgenic, anabolic, progestational and oestrogenic activities or with the relative binding affinities for various endocrine receptors. More elaborate studies with several representative steroids show that testosterone (10 mg/ml), nandrolone (10 mg/ml), 11 alpha-hydroxynandrolone (10 mg/ml), ethylestrenol (1 mg/ml), lynestrenol (1 mg/ml), and Org OD14 [tibolone] (0.1 mg/ml) induce also histomorphological changes in the remaining bursa tissue still present in 10 day- and 53-day old chickens and in the bursa-dependent sites of their spleens (53-day old chickens only). Testosterone and lynestrenol induced smaller changes than nandrolone or ethylestrenol. Tibolone and 11 alpha-hydroxynandrolone were more effective than nandrolone. All drugs, except testosterone and lynestrenol, imparied antibody formation to Newcastle Disease Virus and decreased the serum levels of total IgG, but not of total IgM. Also these effects were not correlated with endocrine properties. In other studies (for references, see text) we found that several of these steroids, notably tibolone, favourably influence the course of spontaneous autoimmune diseases of NZB/W mice and Obese Strain chickens. Since this autoimmunosuppression is likely to be caused by inhibitory effects on bursa or bursa equivalent, we may use this approach for developing medically useful autoimmunosuppressive steroids with minimal endocrine effects.
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D002060:Bursa of Fabricius / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology; D002642:Chick Embryo; D002645:Chickens / Q000033:anatomy & histology*; D005032:Ethylestrenol / Q000494:pharmacology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D008234:Lynestrenol / Q000494:pharmacology; D008297:Male; D009277:Nandrolone / Q000494:pharmacology; D009522:Newcastle disease virus / Q000276:immunology; D009652:Norpregnenes / Q000494:pharmacology; D009929:Organ Size / Q000187:drug effects; D013739:Testosterone / Q000494:pharmacology
D012739:Gonadal Steroid Hormones; D009652:Norpregnenes; D013739:Testosterone; D009277:Nandrolone; D005032:Ethylestrenol; C027385:tibolone; D008234:Lynestrenol