Down-regulation of growth hormone releasing factor receptors following continuous infusion of growth hormone releasing factor in vivo.
The in vivo chronic infusion of growth hormone releasing factor (GRF) results in a loss of the pituitary growth hormone (GH) response to GRF as well as in a substantial depletion of pituitary GH content. To evaluate if the loss in response is due to the down-regulation of GRF receptors the specific GRF binding capacity of pituitary homogenates prepared from rats infused with saline or GRF (1 or 15 micrograms/h for 24 h) was determined. The pituitary binding capacity of animals infused with GRF was significantly reduced as compared to animals infused with saline.
D000818:Animals; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D006706:Homeostasis; D007700:Kinetics; D008297:Male; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018013:Receptors, Neuropeptide; D018017:Receptors, Pituitary Hormone-Regulating Hormone
D011956:Receptors, Cell Surface; D018013:Receptors, Neuropeptide; D018017:Receptors, Pituitary Hormone-Regulating Hormone; D013007:Growth Hormone-Releasing Hormone; C048250:somatotropin releasing hormone receptor