Intercellular communication within the rat anterior pituitary Gland. I. Postnatal development and changes after injection of luteinizing hormone‐releasing hormone (LH‐RH) or testosterone

The postnatal development of gap junction formation and cell‐to‐cell communication were investigated in male rats from 10 through 40 days of age. These junctions initially appeared between adjacent folliculo‐stellate cells on day 20. Their numbers increased until the animals reached the age of 40 days, when their frequency reached a level that resembled that found in adults. The ontogeny of these junctions was examined in rats treated with luteinizing hormone releasing hormone (LH‐RH) or testosterone. The two hormones were injected for 1 week into rats aged 3, 13, 23, or 33 days. The appearance of gap junctions was accelerated in a similar fashion by LH‐RH and testosterone, with their formation and numbers being advanced by 10 days over that observed in the untreated controls. The results suggest a role for the gonadal steroid hormones in the formation of gap junctions in the rat hypophysis.