title: Age-dependent vasodilation of the skin microcirculation by atrial natriuretic factor.
abstract: The microcirculatory responses to systemically administered alpha-human atrial natriuretic factor [99-126)hANF) (ANF) were investigated in the skin of eight young (18-25 years) and eight elderly (71-84 years) healthy volunteers in a double-blind, randomized, placebo-controlled study. Laser-Doppler flux (LDF), transcutaneous oxygen pressure (TcPO2), and skin temperatures on the finger (Td) and on the cheek (Tc) were measured during 60 min of i.v. ANF administration at a low rate (0.25 micrograms/min), resulting in plasma ANF concentrations in the upper normal range, and at a high rate (2.0 micrograms/min), inducing a 17- to 23-fold increase in plasma ANF. ANF infusion did not induce consistent changes in TcPO2 or Td at either rate. Placebo-corrected LDF increased significantly following low-rate ANF infusion in the elderly but remained unchanged in the young (mean +/- SD) +22 +/- 21% (p less than 0.05) and +7 +/- 32% (p greater than 0.1), respectively; following high-rate ANF infusion in LDF the changes were greater, with +28 +/- 56% and +19 +/- 42%, respectively. Because of the large SD the increases were no longer significant. During high-rate ANF infusion Tc remained unchanged in the young, but in the elderly Tc decreased--1.1 +/- 1.3% (p less than 0.05), which is probably due to the fall in blood pressure, which was more pronounced in the elderly than in the young: mean arterial blood pressure (MAP) decreased -9 +/- 3% (p less than 0.05) in the elderly and just -6 +/- 3% (p less than 0.05) in the young, both corrected for placebo changes.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, St. Radboud Hospital, University of Nijmegen, The Netherlands.
authors.forename: T L
authors.initials: TL
authors.lastname: Jansen
authors.forename: A C
authors.initials: AC
authors.lastname: Tan
authors.forename: H
authors.initials: H
authors.lastname: Wollersheim
authors.forename: T J
authors.initials: TJ
authors.lastname: Benraad
authors.forename: T
authors.initials: T
authors.lastname: Thien
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D009320:Atrial Natriuretic Factor / Q000493:pharmacokinetics / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D004232:Diuretics / Q000494:pharmacology; D004311:Double-Blind Method; D005385:Fingers / Q000098:blood supply; D006339:Heart Rate / Q000187:drug effects; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008833:Microcirculation / Q000187:drug effects*; D010101:Oxygen Consumption / Q000187:drug effects; D010446:Peptide Fragments / Q000494:pharmacology; D011897:Random Allocation; D012039:Regional Blood Flow / Q000187:drug effects; D012867:Skin / Q000098:blood supply* / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D004232:Diuretics; D006454:Hemoglobins; D010446:Peptide Fragments; D009320:Atrial Natriuretic Factor