title: Factors associated with vasopressin release in exercising swine.
abstract: This study examined the effect of dynamic exercise on vasopressin release in the miniswine and factors that may elicit this response (n = 15). Thus lysine vasopressin (LVP), the catecholamines epinephrine and norepinephrine (EPI and NE), plasma renin activity (PRA), and plasma volume, Na+, and osmolality were measured before and during treadmill running at work intensities of 60, 80, and 100% of each swine's maximal heart rate reserve (HRR). LVP increased in a progressive manner similar to that of humans, ranging from 5.9 +/- 0.4 pg/ml before exercise to 30.1 +/- 4.5 pg/ml during maximal exercise. EPI, NE, and PRA [an index of angiotensin II (ANG II) activity] demonstrated a pattern of response comparable to LVP. Although these hormones can influence the release of LVP, only PRA displayed a strong correlation with LVP (r = 0.84). When ANG II synthesis was blocked (captopril, 1-3 mg/kg, intra-atrial injection) during exercise (80% HRR), plasma LVP was reduced from 9.9 +/- 0.6 to 7.5 +/- 0.6 pg/ml (P < 0.05). In addition, moderate-to-strong correlations were found between plasma concentrations of LVP and plasma osmolality (r = 0.79) and body temperature (r = 0.78). Plasma LVP also correlated with decreases in plasma volume (r = 0.84). These data suggest that the miniswine model is a good one for studying vasopressin effects during exercise and that ANG II appears to be a particularly strong stimulus for the release of this hormone.
authors.affiliation: Department of Internal Medicine, University of California, Davis 95616.
authors.forename: C L
authors.initials: CL
authors.lastname: Stebbins
authors.forename: J D
authors.initials: JD
authors.lastname: Symons
authors.forename: M D
authors.initials: MD
authors.lastname: McKirnan
authors.forename: F F
authors.initials: FF
authors.lastname: Hwang
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002216:Captopril / Q000494:pharmacology; D004837:Epinephrine / Q000097:blood; D005260:Female; D006439:Hemodynamics; D008236:Lypressin / Q000097:blood / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000097:blood; D005082:Physical Exertion; D012083:Renin / Q000097:blood; D013552:Swine; D013556:Swine, Miniature; D014667:Vasopressins / Q000378:metabolism*
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D014667:Vasopressins; D001127:Arginine Vasopressin; D008236:Lypressin; D002216:Captopril; D012083:Renin; D009638:Norepinephrine; D004837:Epinephrine