Alterations in cholinergic muscarinic and somatostatin binding sites in a patient with idiopathic intestinal pseudo-obstruction

We present a comparative study of cholinergic muscarinic and somatostatin binding sites on isolated membranes from mucosa and tunica muscularis of normal and dilated parts of the proximal jejunum obtained at surgery from a patient with idiopathic intestinal pseudo-obstruction (IIP) syndrome. We found a statistically significant diminution of cholinergic muscarinic and somatostatin binding sites in mucosa taken from the dilated part of the jejunum, compared with those taken from the normal part. Tunica muscularis of the dilated part of the jejunum contained a significantly higher concentration of peripheral cholinergic muscarinic binding sites (M₂) than the normal part did, whereas concentration of M₁ cholinergic muscarinic and somatostatin binding sites was similar in both examined parts. These results indicate that IIP-syndrome may be related to alterations in cholinergic muscarinic binding sites in the tunica muscularis of the intestine.