Changes in serum prolactin following binding and constant light exposure.

The effects of blinding and constant light exposure for 5 weeks on serum concentrations of prolactin were studied in male rats. Neither treatment had any effect on body, pineal, pituitary, testis, or seminal vesicle weights. Serum prolactin was not significantly altered by constant light exposure, but was significantly elevated by blinding. These data provide further support that prolactin secretion is elevated by blinding. It is suggested that prolactin may be partially responsible for the lack of significant gonadal atrophy following blinding in male rats.