Coexistence of growth hormone releasing factor-like and tyrosine hydroxylase-like immunoreactivities in neurons of the rat arcuate nucleus.

Neurons synthesizing growth hormone releasing factor were detected by immunocytochemistry with specific antiserum against synthetic rat hypothalamic growth hormone releasing factor. Growth hormone releasing factor immunoreactive neurons which also showed tyrosine hydroxylase immunoreactivity were located in the ventrolateral part of the arcuate nucleus. The functional significance of this finding for anterior pituitary hormone secretion is discussed.