Sweating in the intact horse and isolated perfused horse skin.
1. In intact horses, heat-induced sweating occurred initially as pulses, then as a continuous, synchronously fluctuating discharge. 2. I.V. adrenaline (Adr) induced sweating immediately; isoprenaline (Isop) elicited sweating after a delay; and phenylephrine (PhE) had no sudorific effect. 3. In isolated perfused skin, PhE induced an immediate small sweat discharge, Isop a slower sustained output and Adr a biphasic discharge. alpha- and beta-adrenergic antagonists blocked the first and second phases, respectively, of Adr-induced sweating. 4. The observed sweating patterns are consistent with independent activation of alpha-adrenergic myoepithelium and beta-adrenergic secretory cells in the sweat glands. 5. Microcirculatory changes apparently also influenced sweat discharge.
D000818:Animals; D001808:Blood Vessels / Q000187:drug effects; D004594:Electrophysiology; D006736:Horses / Q000502:physiology*; D066298:In Vitro Techniques; D010276:Parasympatholytics / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects; D011943:Receptors, Adrenergic, beta / Q000187:drug effects; D012879:Skin Physiological Phenomena; D012881:Skin Temperature / Q000187:drug effects; D013546:Sweating; D013566:Sympathomimetics / Q000494:pharmacology
D010276:Parasympatholytics; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D013566:Sympathomimetics