Dynamics and characterization of plasma immunoreactive beta-melanocyte stimulating hormone in hemodialysis patients: its relationship to ACTH.
We studied the plasma immunoreactive beta-MSH ("beta-MSH") in hemodialysis patients to determine its basal level, plasma disappearance rate, gel filtration and immunological characteristics. All patients had increased plasma "beta-MSH" (90--440 pg/ml; normal less than 90 pg/ml). Plasma ACTH and cortisol values were within the normal range. Cortisol infusion over 2 h induced almost no plasma "beta-MSH" variation as compared to controls where "beta-MSH" decreased rapidly (apparent half-life 90 min.); more prolonged administration of corticosteroids (dexamethasone 0.5 mg every 6 h for two days) caused a slight (20%) but significant (P less than 0.001) decrease of "beta-MSH." On Sephadex G-50 endogenous "beta-MSH" eluted in a molecular weight range of 6,000--10,000. In our radioimmunoassay dilution curves of endogenous "beta-MSH" paralleled that of synthetic human beta-MSH, but not that of purified human beta-LPH. In conclusion, hemodialysis patients show a clear dissociation between elevated "beta-MSH" and normal ACTH plasma levels. "beta-MSH" probably has a decreased plasma disappearance rate and seems related to a substance different from human beta-MSH.
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D002850:Chromatography, Gel; D003907:Dexamethasone; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy; D008297:Male; D009074:Melanocyte-Stimulating Hormones / Q000097:blood* / Q000302:isolation & purification; D008797:Metyrapone; D008875:Middle Aged; D011863:Radioimmunoassay; D006435:Renal Dialysis
D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones; D006854:Hydrocortisone; D008797:Metyrapone