title: The role of the sympathoadrenergic reaction in adaptation of the organism to the action of + 6 Gz acceleration.
abstract: In experiments on rats the symphathoadrenergic reactivity after a + 6 Gz acceleration was investigated. Hypergravitation produced as a rule a short initial bradycardia, followed by tachycardia. Hexamethonium (C6), a peripheric ganglion-blocking agent, produced bradycardia, diminution or vanishing of the initial bradycardic episode, and a decreased tachycardic reaction. No initial bradycardic response was observed ater atropine. Atropinized and C6-treated rats showed an increased heart frequency response. Centrifugation produced a decreased adrenal catecholamine content and a blood noradrenaline elevation. C6 importantly decreased both catecholamines content in blood. On this background the acceleration produced a slight increase of both blood catecholamines.
mesh_terms: D000054:Acceleration; D000222:Adaptation, Physiological; D000313:Adrenal Medulla / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002395:Catecholamines / Q000097:blood* / Q000378:metabolism; D006321:Heart / Q000502:physiology; D006584:Hexamethonium Compounds / Q000494:pharmacology; D051381:Rats; D013564:Sympathetic Nervous System / Q000502:physiology*
chemical_list: D002395:Catecholamines; D006584:Hexamethonium Compounds; D001285:Atropine