Effects of passive immunization against oestradiol-17 beta on some endocrine values of the male lamb.
Passive immunization of male lambs against oestradiol-17 beta from 2 to 16 weeks of age significantly elevated androgen concentrations in plasma and depressed the median eminence content of dopamine. Removal of endogenous oestrogens had no significant effects on plasma FSH, LH or prolactin concentrations or on testicular growth and hypothalamic content of GnRH. These results suggest that endogenous oestrogens may indirectly suppress testicular androgen secretion by exerting a stimulatory influence on hypothalamic dopaminergic neurones, which in turn may inhibit GnRH secretion by the median eminence.
D000728:Androgens / Q000097:blood*; D000818:Animals; D002369:Castration; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000032:analysis; D004958:Estradiol / Q000276:immunology / Q000502:physiology*; D005640:Follicle Stimulating Hormone / Q000097:blood; D007116:Immunization, Passive; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008473:Median Eminence / Q000032:analysis; D010906:Pituitary Hormone-Releasing Hormones / Q000032:analysis; D011388:Prolactin / Q000097:blood; D011863:Radioimmunoassay; D012756:Sheep
D000728:Androgens; D010906:Pituitary Hormone-Releasing Hormones; D004958:Estradiol; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D004298:Dopamine