Plasma beta-endorphin and beta-lipotropin in patients with end-stage renal disease--effects of hemodialysis.

The effect of hemodialysis on the plasma concentration of beta-endorphin (beta-EP) and beta-lipotropin (beta-LPH) was studied in 11 patients with end-stage renal disease (ESRD). The plasma beta-EP/beta-LPH concentrations measured at 13.00 h were not significantly different in the patients compared to age-matched controls. Furthermore, hemodialysis produced no change in the plasma concentrations of beta-EP/beta-LPH. The elevated levels of beta-EP/LPH previously reported are most likely a reflection of the measurement of these peptides at a time of peak diurnal secretion compounded by a fall in the metabolic clearance rate of the endogenous opioids in ESRD. It remains to be established whether measurement of adronocorticotropic hormone or beta-EP/beta-LPH is more accurate an indicator of the integrity of the hypothalamic-pituitary-adrenal axis in patients with ESRD.