[Influence of thermal dehydration on blood values of hormones which regulate volume and composition of electrolytes in sweat of patients with ic renal failure treated with hemodialysis].

The present study has aimed to answer the following questions: 1) to what extent does the profile of volume related hormones in patients with chronic renal failure (CRF) differ from that of healthy subjects, and 2) do volume related hormones influence the electrolyte composition of thermal sweat? Twelve hemodialyzed patients with CRF and 20 healthy subjects were examined before and after one hour exposition to humid heat. In all examined subjects the following parameters were assessed before and after thermal dehydration: plasma renin activity (PRA) and plasma aldosterone (Ald), vasopressin (AVP) and atrial natriuretic peptide (ANP) concentrations. In addition sodium, potassium, and chloride were estimated in thermal sweat collected after 15 and 45 minutes respectively of thermal exposition. Patients with CRF showed significantly higher values of PRA, Ald, AVP and ANP before thermal dehydration. After one hour of heat exposition a significant increase in PRA, Ald and AVP but a significant decrease of plasma ANP level were noticed in both healthy subjects and patients with CRF. The magnitude of plasma Ald and ANP alterations induced by thermal dehydration was significantly more marked in patients than in healthy subjects. A similar electrolyte composition of thermal sweat was found in both examined groups. No significant correlation was found between the plasma profile of volume related hormones and electrolyte composition of sweat both in patients and normals. Results presented in this paper suggest, that volume related hormones do not influence the electrolyte composition of thermal sweat both in healthy subjects and patients with CRF.