AbstractThe effects of combined blinding and olfactory bulbectomy alone or with pinealectomy on body growth, and pituitary and serum levels of growth hormone and prolactin were examined in young female rats. The animals were 23–24 days old at the time of the operations, and they were sacrificed 52 days later. Blind, anosmic rats had elevated serum and depressed pituitary stores of prolactin. The blind, anosmic rats which were also pinealectomized showed prolactin levels which were intermediate between those of the blind, anosmic and sham control animals. On the other hand, combined blindness and anosmia decreased serum growth hormone levels and again pinealectomy prevented this effect. The observed changes in the ultrastructure of prolactin and growth hormone cells were well correlated with these alterations in hormone levels.