GASTROINTESTINAL REGULATORY PEPTIDES IN SYSTEMIC-SCLEROSIS

Objective. Gastrointestinal involvement commonly occurs in systemic sc lerosis (SSc), but its pathogenesis is not well understood. Since ther e is evidence of a defect in neurotransmitter release, we were interes ted in examining the relationship between gastrointestinal dysfunction and plasma concentrations of gastrointestinal regulatory peptides in patients with SSc. We studied 43 consecutive patients, 18 with diffuse and 25 with limited cutaneous disease. Methods. Levels of corticotrop in-releasing hormone (CRH), gastrin, motilin, neuropeptide Y (NPY), an d peptide YY (PYY) were determined by radioimmunoassay and high-perfor mance liquid chromatography (HPLC). Results. Plasma concentrations of CRH, motilin, NPY, and PYY were significantly increased among SSc pati ents compared with healthy control subjects, and HPLC-characterization of motilin, NPY, and PYY showed a different pattern of fragments. No correlation was found between esophageal hypomotility and the concentr ation of peptide. Acid output did not correlate with gastrin levels, b ut was more often increased in patients with increased CRH and NPY val ues. Fat malabsorption, assessed by the triolein breath test, was more common among patients with increased motilin and PYY. Conclusion. Thi s study shows that elevated peptide concentrations commonly occur in p atients with SSc. Since regulatory peptides are involved in gastrointe stinal motility, secretion, and absorption, further characterization o f this neuroendocrine system may help in understanding the complex reg ulation of gastrointestinal dysfunction in SSc.