Abstract
Plasma concentrations of somatostatin-like immunoreactivity (SLI) were determined in uremic patients on maintenance hemodialysis. Plasma SLI levels were significantly (p<0.001) elevated in26diabetic uremic patients (67.1±6.8 pg/ml, mean±SE) and in 24 non-diabetic uremic patients (43.5±7.2pg/ml), when compared with60healthy subjects (5.0±0.7pg/ml).
Paired pooled plasma from uremic patients before and after hemodialysis was subjected to a reverse-phase octadecasilyl-silica (C-18) cartridge and then the extract was gel filtered on a Sephadex G-25column (1.6×90cm). Both elution profiles showed two peaks of SLI which coeluted with synthetic somatostatin (SS)-28and SS-14 markers, respectively. The SS-28-like immunoreactivity (LI) peak, which was estimated by using SS-14as a reference standard, was 3-fold larger than that for SS-14 LI. On the basis of immunoequivalency of the two components in the present assay, SS-28 LI constitutes approximately 75% of circulating somatostatin.
In conclusion, plasma SLI is substantially high in uremic patients of both diabetic and non-diabetic etiology and the SS-28 is a predominant form of circulating SLI in these patients, probably, in part, for a lower clearance of this molecule.
