Evidence for thyrotropin-releasing hormone and glucocorticoid receptor-immunoreactive neurons in various preoptic and hypothalamic nuclei of the male rat.
Neurons containing thyrotropin-releasing hormone (TRH) and glucocorticoid receptor (GR) immunoreactivity (IR) were demonstrated by a two-colour immunoperoxidase method in coronal cryotome sections of the preoptic region and the hypothalamus of the male rat brain. All the TRH-IR neurons (TRH-IR) located in the dorsal hypothalamus - medial and dorsal parvocellular parts of the paraventricular hypothalamic nucleus and the dorsomedial hypothalamic nucleus - and in the anterior periventricular hypothalamic nucleus were strongly GR-IR. The TRH-IR neurons of the medial preoptic area, the perifornical nucleus and the medial tuberal area were mostly weakly GR-IR and some lacked GR-IR. These data indicate a differential regulation of diencephalic TRH-IR neurons by glucocorticoids. They also imply that the inhibitory effect of glucocorticoids on TSH secretion may involve a direct inhibition of TRH synthesis and/or release by a nuclear action in the TRH-IR nerve cells of the paraventricular hypothalamic nucleus projecting to the median eminence.
Cintra
A
A
Department of Histology and Neurobiology, Karolinska Institutet, Stockholm, Sweden.
Fuxe
K
K
Wikström
A C
AC
Visser
T
T
Gustafsson
J A
JA
D000818:Animals; D007031:Hypothalamus / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D011301:Preoptic Area / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011965:Receptors, Glucocorticoid / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism*
D011965:Receptors, Glucocorticoid; D013973:Thyrotropin-Releasing Hormone