Less acidic forms of luteinizing hormone are associated with lower testosterone secretion in men on haemodialysis treatment

Objective. Chronic renal failure treated by haemodialysis have raised levels of bioactive LH (B-LH) and immunoreactive LH (I-LH) but reduced B-LH:I-LH (B:I) ratio and testosterone (T) secretion. This study investigated the LH isoform distribution in serum from normal adult males and males on regular haemodialysis treatment. Design. Four blood samples (2 ml) were obtained at 15 minute intervals from a group of men on regular haemodialysis treatment. These samples were part of a larger pulse profile series and showed no evidence of LH pulsatility. The serum was pooled for each individual patient. Blood (10 ml) was also drawn randomly from healthy male volunteers. The sera were chromatofocused on a 4-ml mono-P column attached to a fast performance liquid chromatography system. This procedure separates the LH isoforms according to their isoelectric point. the pH gradient was between pH 7 and pH 4. Patients. The five men with chronic renal failure were aged between 18 and 40 years and had been on haemodialysis for a mean of 10 months (5-20). They were sampled the night prior to a dialysis session. The five normal healthy volunteers had never had any endocrine disorder diagnosed. Measurements. An immunoradiometric assay and a commercially available (Delfia) immunofluorimetric assay were employed for detection of LH in the sera and in chromatofocusing fractions. B-LH and testosterone were also measured in the sera.