Physiological roles of corticotropin-releasing hormone receptor type 2.
Recent investigations of the physiological roles of CRH-R2 are reviewed and summarized in Fig. 5. VMH CRH-R2 is more important than CRH-R1 in mediating anorexic effect of CRH or urocortin (UCN) and stress-induced reduction of food intake. CRH-R2 mediates a central anxiolytic response, opposing the anxiogenic effect of CRH mediated by CRH-R1. Hippocampal CRH-R1 mediates stress-induced enhancement of learning, while CRH-R2 in the lateral intermediate septum may act to impair learning. CRH-R1 mediates CRH-induced blood pressure elevation, while peripheral CRH-R2 mediates the hypotensive effect of systemically administered UCN and CRH. It is likely that CRH-R2 does not play an important role in hypothalamic-pituitary adrenal axis regulation, though it has been reported that CRH-R2-deficient mice showed hyperresponse of ACTH and corticosterone. Peripheral CRH-R2 mediates UCN-induced mast cell degranulation, vascular permeability, and abdominal surgery-induced gastric stasis. These recent investigations have revealed that the existence of two CRH receptors, which mediate some opposite effects, provides the CRH and UCN systems a high flexibility and dynamic role in the adaptation of the body to environmental challenge.
Hashimoto
K
K
Second Department of Internal Medicine, Kochi Medical School, Japan.
Makino
S
S
Asaba
K
K
Nishiyama
M
M
D000311:Adrenal Glands / Q000502:physiology; D000818:Animals; D001007:Anxiety; D001835:Body Weight; D002320:Cardiovascular Physiological Phenomena; D004435:Eating; D006706:Homeostasis; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007858:Learning; D008568:Memory; D018019:Receptors, Corticotropin-Releasing Hormone / Q000502:physiology*
D018019:Receptors, Corticotropin-Releasing Hormone