A comparative immunological study of pituitary growth hormone from various species

Similarities and differences in the antigenic structures of pituitary growth hormone (somatotropin, STH) from various species were studied by means of anaphylactic shock experiments in guinea pigs, precipitin ring tests and agar gel-diffusion studies with antisera to highly purified bovine and human STH. Antihormone tests in hypophysectomized rats were also performed, with the same antisera. The results of the above studies have suggested that the antigenic structures of pituitary STH from man and monkeys are very similar to one another, but are clearly different from those of the whale, hog, sheep, ox, horse and fish; and, furthermore, that the antigenic structures of sheep and ox STH’s are closety related, but quite different from STH of all other species tested. It was also demonstrated that antiserum to either the bovine or human purified STH could not only detect minute amounts of the homologous purified STH in saline solution and neutralize its biological activity, but could also detect STH in a cru...