Plasma immunoreactive melanotrophic hormones in patients on maintenance haemodialysis.

Circulating levels of melanotrophic horomones and ACTH were determined in patients treated by maintenance dialysis for chronic renal failure. Plasma melanotrophic hormone levels were greatly increased in all patients studied (125-1100 ng/1 as compared with 12-36 ng/1 in normal adults) and were correlated with the duration of treatment. Skin pigmentation, especially in exposed areas, was notably increased, particularly in those patients with the highest plasma melanotrophic concentrations. Plasma ACTH levels were normal or only slightly raised and circulating corticosteroid concentrations, as determined by a fluorimetric method, all lay within the physiological range. The dissociation between ACTH and melanotrophic hormone levels in these patients may have been the result of a slower metabolic clearance of the latter.