LANREOTIDE INHIBITS HUMAN JEJUNAL SECRETION INDUCED BY PROSTAGLANDIN E(1) IN HEALTHY-VOLUNTEERS

1 Somatostatin inhibits hormonal secretions in the gastrointestinal tr act. Somatostatin analogues are used in the treatment of VIPome-relate d watery diarrhoea. In addition, more than 10% of patients with AIDS s uffer from diarrhoea likely due to the increased intestinal secretion of water and ions, However, the direct effect of somatostatin on the f lux of water and ions in the intestine has not been, so far, analyzed in vivo. The aim of the present study was to evaluate the effect of la nreotide, a somatostatin analogue, on the movements of water and ions in the jejunum in man. 2 Accordingly, 10 healthy volunteers (age 18-35 years, mean 27) and two patients with AIDS (26 and 33 years) sufferin g from water diarrhoea (> 800 ml day(-1)) underwent intestinal perfusi on using a four lumen tube with proximal occluding balloon. The segmen t tested was 25 cm long. The jejunum was infused by an isotonic contro l saline solution containing polyethylene glycol (PEG) as nonabsorbabl e marker. Basal jejunal secretions were measured in all subjects. Pros taglandin E(1) (PGE(1)) was administered intraluminally to stimulate j ejunal secretion in healthy volunteers. The effect of intravenous lanr eotide on the jejunal PGE(1)-induced secretions of water and electroly tes was analysed in healthy subjects and on the basal secretions in AI DS patients. Each period was analyzed on the basis of three (10 min) s uccessive intestinal juice collections after 20-30 min equilibration t ime. The antisecretory effect of lanreotide was evaluated in each subj ect as the difference between fluxes compared to the control period. 3 In healthy volunteers, PGE(1) induced secretion of H2O, Na+, K+ and C l- in the jejunum and lanreotide reduced significantly PGE(1)-induced response. In both AIDS patients basal fluxes of water and ions were re duced by lanreotide in a dose-dependent manner. 4 Somatostatin can red uce stimulated-jejunal secretion of ions and water in normal subjects and may improve water diarrhoea in AIDS patients.