The organum vasculosum laminae terminalis (OVLT), which lacks the blood brain barrier and plays a bridgehead between circulation and cerebralventricle by signaling the brain to keep the body’s homeostasis , is richly innervated by noradrenergic nerve terminals derived from the brainstem. The object of this study was to assess the role of a- and b-
adrenoceptors on thermoregulatory responses to different ambient temperatures in OVLT.The intra-OVLT injections of adrenaline (1-50 mg), isoproterenolol (1-50 mg), or db-cAMP (1-50 mg) showed an increase in colonic temperature, an increase in metabolic rate, and a decrease in foot and tail skin temperature at ambient temperatures (Ta) of 22 and 32℃, but did not affected at Ta of 8℃. Furthermore, the intra-OVLT injections with phynylephrine (0.1-10 mg), and propranolol (1-50 mg) showed a decrease in colonic temperature, a decrease in metabolic rate, and an increase in foot and tail skin temperature at Ta of 22℃, but did not affected by clonidine (0.01-1 mg). Propranolol acted in the OVLT to produce hypothermia responses and block the hyperthermia induced by intra-OVLT injections of adrenaline. The results suggested that the adrenoceptors in the OVLT of rat’s brain may be involved in thermal regulation. Activation of adrenocaptors may induce hyperthermia (due to increased heat production and decreased heat loss mechanisms), whereas inhibition of adrenoceptors may induce hypothermia (due to decreased heat production and increased heat loss mechanisms). 血管脈絡叢地區缺乏血腦障壁的保護,並富含來自腦幹交感神經末稍的分佈,透過和血液循環和腦室循環的物質反應,扮演著維持身體恆定作用的橋樑角色。本研究目的在於探討交感神經a及ß型受體在不同環境溫度下對血管脈絡叢地區的體溫調節影響。維持環境溫度為22℃及32℃時(非8℃之低溫環境),ß型受體作用劑腎上腺素(adrenaline, 1-50 mg)、isoproterenolol(1-50 mg)和db-cAMP (1-50 mg)能經由血管脈絡叢地區的作用,提升大白鼠核心體溫、增加新陳代謝速率和周邊血管緊縮現象。