Impaired renal responsiveness to human atrial natriuretic peptide (hANP) in normotensive patients with type 1 diabetes mellitus

Abstract
Potential impairment of the efficacy of human atrial natiuretic peptide (human ANF-(99-126), hANP), the most potent endogenous natriuretic agent in healthy subjects, was examined in eight male normotensive patients with uncomplicated type 1 diabetes mellitus (aged 22–37 years). After giving informed consent, patients and eight male control subjects (aged 22–28 years) received in a random double-blind study design i.v. bolus injections of 100 µg hANP (Bissendorf peptide) or placebo. At base-line, patients differed from controls in elevated creatinine clearance (PPPP<0.05 vs placebo). Heart rate and blood glucose remained unchanged. Thus, there is evidence for a decreased responsiveness to hANP exclusively of renal fluid, sodium, and chloride excretion in uncomplicated type 1 diabetes mellitus. The mechanisms responsible for this phenomenon remain obscure, neither a down regulation at the hANP receptor sites nor an hANP-induced shift from intra- to extravascular fluid volume are likely to be involved in its probably diabetes-specific pathogenesis.