Pituitary concentration of GH messenger ribonucleic acid in rats with anterolateral hypothalamic deafferentation

To study neuronal mechanism through which the hypothalamus exerts its influence on growth hormone (GH) synthesis, anterolateral hypothalamic knife cuts (ALHD) were used. After ALHD, GH messenger RNA (mRNA) content in the pituitary was reduced to 47% of the control value. Neither the prolactin mRNA level nor the total DNA content showed any significant change. In such animals, the serum GH level was significantly higher (184%) and pituitary GH content was lower (43%) than the control values. These results suggest that neuronal factor(s) outside the mediobasal hypothalamus plays an important role in the regulation of GH synthesis.