Electrolytic lesions of the dorsal rostral pons prevent adrenocorticotropin increases after hemorrhage.
To determine if a discrete area of the dorsal rostral pons in the region of the locus coeruleus (LC) is essential for the reflex response of ACTH to hemorrhage, chloralose-anesthetized cats with bilateral electrolytic (11 cats) or sham (3 cats) lesions were challenged with a 15 ml/kg X 3 min hemorrhage. Sequential arterial blood samples taken at -6, -3, 3, 6, 9, 15, and 21 min from hemorrhage were analyzed for ACTH content. Cats were grouped according to whether plasma ACTH increased in response to hemorrhage. Bilateral lesions in 7 cats with an area in common, which lay within the LC complex, blocked the reflex increase in plasma ACTH in response to hemorrhage which was seen in 3 sham-lesioned cats, in 3 cats with lesions that did not infringe in this region bilaterally, and in 1 cat with lesions that infringed only on the medial-ventral aspect of the LC-subcoeruleus. These findings suggest that hemodynamic information responsible for the reflex response of ACTH to hemorrhage of this magnitude passes through a discrete region of the dorsal rostral pons.
D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000378:metabolism*; D000818:Animals; D002415:Cats; D006470:Hemorrhage / Q000503:physiopathology*; D007700:Kinetics; D008297:Male; D011149:Pons / Q000502:physiology / Q000503:physiopathology*
D000324:Adrenocorticotropic Hormone