title: Effects of potassium loading in normal man on dopaminergic control of mineralocorticoids and renin release.
abstract: The interacting effects of potassium with the dopaminergic control of mineralocorticoid release were evaluated in normal man. Sixteen male healthy volunteers [27 +/- 6 (s.d.) years] on a 200 mmol sodium (Na+) and 60 mmol potassium (K+) diet (control) received a K+ load of 200 mmol/day for 6 days (high-K+ diet). Basal plasma aldosterone and 18-OH-corticosterone (18-OH-B) levels were significantly increased after 6 days of the high-K+ diet, whereas basal levels of 18-OH-deoxycorticosterone (18-OH-DOC) and corticosterone remained unchanged. Fifteen minutes after 10 mg i.v. of the dopaminergic antagonist, metoclopramide, a significant increase was only obtained for basal plasma aldosterone and 18-OH-B levels. The absolute rise of aldosterone and 18-OH-B induced by metoclopramide was greater (P less than 0.01) after K+ supplementation. However, the relative increase of these hormones was similar before and after K+ loading. Basal plasma renin activity increased significantly under high-K+ diet. The results indicate that K+ homeostasis must be taken into account when estimating absolute response of aldosterone and 18-OH-B to dopaminergic antagonism.
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000097:blood*; D001794:Blood Pressure; D003345:Corticosterone / Q000097:blood*; D003900:Desoxycorticosterone / Q000097:blood*; D004032:Diet; D004298:Dopamine / Q000502:physiology*; D006706:Homeostasis; D006801:Humans; D008297:Male; D008787:Metoclopramide; D011188:Potassium / Q000008:administration & dosage; D012083:Renin / Q000378:metabolism*; D012965:Sodium Chloride / Q000008:administration & dosage
chemical_list: D003900:Desoxycorticosterone; D012965:Sodium Chloride; D000450:Aldosterone; D012083:Renin; D008787:Metoclopramide; D011188:Potassium; D004298:Dopamine; D003345:Corticosterone