title: Effects of low- and high-intensity exercise on plasma and cerebrospinal fluid levels of ir-beta-endorphin, ACTH, cortisol, norepinephrine and glucose in the conscious dog.
abstract: This study was designed to assess effects of exercise on plasma and cerebrospinal fluid (CSF) levels of immunoreactive (ir) beta-endorphin, ACTH, cortisol, norepinephrine, and glucose in the conscious dog. Dogs were exercised on a treadmill at low or high intensity (4.2 miles/h and a 6% or 20% incline) for 90 min, and were allowed to recover for 90 additional min. Neither intensity of exercise changed plasma glucose levels, but dose-related changes in glucose kinetics did occur. CSF glucose declined in both groups. During low intensity exercise, plasma levels of ir-beta-endorphin, ACTH, and cortisol increased with duration of exercise. During high intensity exercise, ACTH, ir-beta-endorphin and cortisol increased faster, and the integrated plasma response of these hormones was greater. Thus, peripheral release of ir-beta-endorphin, ACTH, and cortisol during exercise is dose-related with respect to time and intensity. CSF ir-beta-endorphin and ACTH both increased during low- but not high-intensity exercise. CSF cortisol rose markedly in both exercise groups. During high-intensity exercise there was a 50% increase in CSF norepinephrine, indicating that exercise induces alterations in central noradrenergic turnover. We conclude that exercise is a physiologic regulator of both peripheral and central neuroendocrine systems.
authors.affiliation: Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN 37232.
authors.forename: P M
authors.initials: PM
authors.lastname: Radosevich
authors.forename: J A
authors.initials: JA
authors.lastname: Nash
authors.forename: D B
authors.initials: DB
authors.lastname: Lacy
authors.forename: C
authors.initials: C
authors.lastname: O'Donovan
authors.forename: P E
authors.initials: PE
authors.lastname: Williams
authors.forename: N N
authors.initials: NN
authors.lastname: Abumrad
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood* / Q000134:cerebrospinal fluid; D000818:Animals; D004285:Dogs; D004723:Endorphins / Q000097:blood* / Q000134:cerebrospinal fluid; D005260:Female; D005947:Glucose / Q000134:cerebrospinal fluid / Q000378:metabolism*; D006854:Hydrocortisone / Q000097:blood* / Q000134:cerebrospinal fluid; D008297:Male; D009638:Norepinephrine / Q000097:blood* / Q000134:cerebrospinal fluid; D005082:Physical Exertion; D013997:Time Factors
chemical_list: D004723:Endorphins; D000324:Adrenocorticotropic Hormone; D005947:Glucose; D006854:Hydrocortisone; D009638:Norepinephrine