title: Adrenergic receptors of adrenal medullary vasculature.
abstract: The present study evaluates possible effects of adrenal catecholamines, released by splanchnic nerve stimulation, on adrenal medullary blood flow (MQ) and adrenal catecholamine secretion (CS). Twelve pentobarbital-anesthetized mongrel dogs were subjected to three identical splanchnic nerve stimulations (5 V, 20 Hz, for 3 min) at 30-min intervals, and MQ (radiolabeled microsphere technique) and CS (high-performance liquid chromatography) were measured before and during each nerve stimulation. Animals were assigned to one of three groups and administered either saline, pindolol (1 and 4 mg/kg), or prazosin (1 and 4 mg/kg) before the second and third nerve stimulation, respectively. In the saline control group, each nerve stimulation resulted in similar increases in MQ and CS. Pindolol attenuated nerve stimulation-induced increases in MQ and CS by 50%, but had no effect on medullary catecholamine concentration. Prazosin augmented nerve stimulation-induced MQ, CS, and medullary catecholamine concentration by 35%. These data suggest that adrenal adrenergic receptors modulate elicited CS and mediate changes in adrenal medullary vascular tone.
authors.affiliation: Department of Anesthesiology, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205.
authors.forename: D A
authors.initials: DA
authors.lastname: Jordan
authors.forename: M J
authors.initials: MJ
authors.lastname: Breslow
authors.forename: K L
authors.initials: KL
authors.lastname: Kubos
authors.forename: R J
authors.initials: RJ
authors.lastname: Traystman
mesh_terms: D000313:Adrenal Medulla / Q000098:blood supply*; D000818:Animals; D002395:Catecholamines / Q000502:physiology*; D004285:Dogs; D006470:Hemorrhage / Q000150:complications; D007022:Hypotension / Q000209:etiology / Q000503:physiopathology; D008863:Microspheres; D010869:Pindolol / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D011941:Receptors, Adrenergic / Q000502:physiology*; D012039:Regional Blood Flow; D013153:Splanchnic Nerves / Q000502:physiology; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D002395:Catecholamines; D011941:Receptors, Adrenergic; D010869:Pindolol; D011224:Prazosin