Thyrotropin, Prolactin and Growth Hormone Response to Synthetic Thyrotropin-Releasing Hormone in Newborn Infants

Abstract
The effects of 50 μg synthetic thyrotropin-releasing hormone (TRH) intravenously on thyrotropin (TSH), prolactin (PRL) and growth hormone (GH) levels were studied in 8 normal male newborns during the first hours of life. Mean plasma GH concentrations were similar to baseline values during the period of study; on the contrary, plasma PRL and TSH values increased in all infants after TRH administration. These data demonstrate a normal pituitary reserve of PRL and TSH in the early period of human life.