title: Sympathetic control of adrenal secretion of enkephalins after hemorrhage in awake dogs.
abstract: Adrenomedullary secretion of methionine (Met)-enkephalin and of leucine (Leu)-enkephalin was measured in awake trained dogs subjected to 10 or 20% hemorrhage. Enkephalin secretory rates increased in proportion to the magnitude of hemorrhage with the ratio of Met-enkephalin to Leu-enkephalin being approximately 4:1. Arterial concentrations of enkephalins reflected adrenal secretion only in dogs exhibiting the largest secretory responses to hemorrhage. Cross-correlation analysis of 12 individual experiments showed that Met-enkephalin and epinephrine secretory rates were maximally correlated at 0-min delay, suggesting that enkephalins are cosecreted with catecholamines. The molar ratio in adrenal venous blood of epinephrine to Met-enkephalin ranges from 480 +/- 50 to 570 +/- 60. Chronic denervation of the adrenal by removing thoracic and lumbar splanchnic nerves prevented the Met-enkephalin and catecholamine secretory responses to hemorrhage. These data show that the adrenal medulla secretes enkephalins in response to stimuli activated by hemorrhage. These findings suggest that secretion of opiate-like peptides into the peripheral circulation may be a component of the sympathetic response to trauma.
mesh_terms: D000311:Adrenal Glands / Q000294:innervation / Q000378:metabolism*; D000818:Animals; D001158:Arteries; D003714:Denervation; D004285:Dogs; D004743:Enkephalin, Leucine / Q000378:metabolism*; D004744:Enkephalin, Methionine / Q000097:blood / Q000378:metabolism*; D004837:Epinephrine / Q000378:metabolism; D005260:Female; D006439:Hemodynamics; D006470:Hemorrhage / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D009638:Norepinephrine / Q000378:metabolism; D013564:Sympathetic Nervous System / Q000502:physiology*; D014851:Wakefulness
chemical_list: D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; D009638:Norepinephrine; D004837:Epinephrine