title: Episodic nature of the delta 4-ene and delta 5-ene steroidogenic pathways and their relationship to the adreno-gonadal axis in stallions.
abstract: Changes in the daily secretory patterns of testosterone and other 17 beta-hydroxyandrogen, total oestrogens and total corticoids were investigated in 7 stallions. Pulsatile fluctuations in plasma hormone levels were found in the serial blood samples collected hourly for 24 h in all animals. The plasma profiles indicated that corticoids, oestrogens and androgens were secreted episodically at all times in stallions. A significant correlation was observed between the precursor and products of delta 4-ene and delta 5-ene pathways and in inverse correlation (r = -0.68; P less than 0.01) was observed between total androgens and total corticoids. The significance of these episodic fluctuations of the major steroid hormones are discussed.
mesh_terms: D000305:Adrenal Cortex Hormones / Q000097:blood; D000728:Androgens / Q000097:blood*; D000734:Androstenediols / Q000097:blood; D000735:Androstenedione / Q000097:blood; D000818:Animals; D003687:Dehydroepiandrosterone / Q000097:blood; D013196:Dihydrotestosterone / Q000097:blood; D004967:Estrogens / Q000097:blood; D006736:Horses / Q000502:physiology*; D008297:Male; D010507:Periodicity; D013739:Testosterone / Q000378:metabolism*
chemical_list: D000305:Adrenal Cortex Hormones; D000728:Androgens; D000734:Androstenediols; D004967:Estrogens; D013196:Dihydrotestosterone; D013739:Testosterone; D000735:Androstenedione; D003687:Dehydroepiandrosterone