To determine the effects of ingested royal jelly (RJ) on the pituitary in middle-aged female rats, we performed a long-term RJ administration test. Several animals showed age-related increases in pituitary weight, and RJ administration compensated for the increase. RJ tended to down-regulate prolactin mRNA and up-regulated thyroid-stimulating hormone β mRNA in the pituitary. This suggests that RJ compensates for age-associated decline in pituitary functions.
