Responses of plasma renin activity and dopamine-beta-hydroxylase to increased intravascular volume.
Circadian variations of plasma renin activity, plasma dopamine-beta-hydroxylase, and urinary aldosterone excretion were measured in man under conditions of high- and low-sodium intake. Plasma renin activity and urinary aldosterone excretion were maximal at 8 a.m. Plasma DBH shows small, biologically insignificant circadian fluctuations. In three subjects on low-salt diets, the values were lower than those in the same subjects on high-salt diets. Expansion of intravascular volume in supine normal volunteers lowered plasma renin and DBH activity, and also resulted in a significant natriuresis. The decline in DBH activity probably reflects a decrease in its release from autonomic nerve endings and thus demonstrates in man an effect of decreasing autonomic activity.
D015065:17-Hydroxycorticosteroids / Q000652:urine; D000293:Adolescent; D000328:Adult; D000368:Aged; D000450:Aldosterone / Q000652:urine; D001810:Blood Volume; D002940:Circadian Rhythm; D003404:Creatinine / Q000652:urine; D004032:Diet; D004299:Dopamine beta-Hydroxylase / Q000097:blood*; D006400:Hematocrit; D006801:Humans; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000652:urine; D012083:Renin / Q000097:blood*; D012709:Serum Albumin; D012964:Sodium / Q000652:urine
D015065:17-Hydroxycorticosteroids; D012709:Serum Albumin; D000450:Aldosterone; D012964:Sodium; D003404:Creatinine; D004299:Dopamine beta-Hydroxylase; D012083:Renin; D011188:Potassium