Plasma Changes of Pituitary Protein 7B2 in Chronic Renal Failure Before and After Haemodialysis, Comparisons with Pituitary Hormones and Neuropeptides

Pituitary protein 7B2, is a highly conserved molecule, located in the gonadotrophs and released by luteinising hormone releasing hormone (LHRH), in vitro and in vivo. 7B2-immunoreactivity (7B2-IR) was estimated in patients with chronic renal failure (CRF) before and after haemodialysis. Twenty patients (twelve male, eight female) aged 18-67 (43.9 + 17.7 [SD]) years with CRF were studied before and after haemodialysis. A blood sample was taken from the haemodialysis access site (Cimino fistula) [n=13] or Scribner shunt [n=7]. Haemodialysis was then carried out using a hollow fibre AK 10 dialyser and Gambro control unit. A second blood sample was taken ten minutes after the end of haemodialysis. Pre and post-dialysis blood pressure, pulse and weight were recorded. Plasma creatinine was also recorded before and after haemodialysis. 7B2IR was est imated us ing a sens i t ive radioimmunoassay (RIA). Chromatography was used to verify the expected elution position of 7B2. Mean plasma creatinine fell from 1223 + 52 (645 1500) μmol/l before to 546 + 40 (230-900) μmol/l after haemodialysis (p < 0.001). 7B2 concentrations in 20 patients with CRF before haemodialysis were found to be 123 + 7.4 pmol/l; post-dialysis 7B2 levels were 262 + 19.5 pmol/l, significantly increased compared to those seen during pre-dialysis (p < 0.01). 7B2 levels in patients with CRF correlated positively with plasma creatinine (r = 0.48, p < 0.04). Α representative chromatographic profile of 7B2– IR in plasma of CRF patients eluted at the expected position. 7B2-IR is increased in CRF patients and is further increased after haemodialysis.