Ovine chorionic somatomammotropin and foetal growth.

Ovine chorionic somatomammotropin (oCS) enhances the weight and bone growth of hypophysectomized rats. It acts as a bifunctional hormone, since it binds both to lactogenic and somatotropic receptors. Ovine foetus weight gain is closely related to oCS and oGH serum levels. oCS is able to stimulate somatomedins by foetal liver. Moreover, oCS specific receptors are present in some foetal tissues. So, all these facts involve oCS in foetal growth, whereas pituitary growth hormone intervenes in postnatal growth. A study of structure function relationships between growth hormones and placental hormones is exposed in order to localize somatotropic sites.