The possible luteotrophic effect of guinea-pig chorionic gonadotrophin

Studies into human pregnancy have many practical applications such as in fertility regulation. Such studies cannot be done in women for ethical reasons and a suitable animal model has to be identified. Though guinea-pig is known to secrete a CG-like protein, the precise function of this material during early pregnancy has not been elucidated. We assessed the effect of guinea-pig chorionic gonadotrophin (gpCG) on luteal tissue kept in-vitro. This involved short-term culture of the luteal tissue cells and the subsequent measurement of progesterone following challenge with gpCG. Guinea-pig CG stimulated progesterone production by cultured luteal tissue and this suggests that this hormone, as in primates, has a luteotrophic role during pregnancy. We conclude that the guinea-pig provides a useful homologous model for studying early pregnancy events in humans.