Peptide YY abnormalities in patients with ulcerative colitis.

Peptide YY concentrations in both rectal mucosa and fasting plasma, which were produced by endocrine cells in the lower gastrointestinal tract, were measured in normal subjects and patients with ulcerative colitis by specific radioimmunoassay and were examined in the relation to histopathological changes and extent of lesions of ulcerative colitis. Peptide YY levels of rectal mucosa (11.0 +/- 1.4 pmol/mg protein) and fasting plasma (53.3 +/- 7.9 fmol/ml) of patients with ulcerative colitis were significantly lower (p less than 0.001) than those of normal subjects (31.5 +/- 3.4 pmol/mg protein and 160.7 +/- 19.7 fmol/ml). It appears that the decreased PYY level in rectal mucosa and fasting plasma is related to crypt destruction and reduction of mucosal cell. These changes of PYY levels in rectal mucosa and fasting plasma suggest a presence of relationship between concentrations of peptide YY and severity of lesions in patients with ulcerative colitis.