title: Beta blockers and exercise: physiologic and biochemical definitions and new concepts.
abstract: Exercise training effects occur in man after chronic exposure to aerobic exercise, which should be defined quantitatively to permit a precise mechanistic understanding. Exercise adaptations result from circulatory and metabolic changes that involve altered responsiveness to neurohumoral transmitters at the receptor level. The adrenergic mechanisms are most important and are linked to new understandings of the adrenergic receptor and its coupling with biochemical processes in the cell. The adrenergic receptor is a specialized protein in the cell membrane linked to the catalytic moiety of the enzyme adenylate cyclase by a coupling protein controlled by guanine nucleotides. The sensitivity of this receptor mechanism may be altered by exposure to agonists and antagonists and by circulatory and metabolic diseases. The effects of beta- adrenergic blockers on exercise adaptation and the clinical sequelae are emphasized.
authors.forename: D C
authors.initials: DC
authors.lastname: Harrison
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000319:Adrenergic beta-Antagonists / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D002320:Cardiovascular Physiological Phenomena; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D018377:Neurotransmitter Agents / Q000037:antagonists & inhibitors / Q000378:metabolism; D005082:Physical Exertion; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*
chemical_list: D000319:Adrenergic beta-Antagonists; D018377:Neurotransmitter Agents; D011943:Receptors, Adrenergic, beta; D000262:Adenylyl Cyclases