Abstract 45

Despite extensive study, a role for gastrin in the development of Infantile Pyloric Stenosis (IPS) remains to be established. Somatostatin is a major antagonist of gastrin, is known to influence non-adrenergic non-cholinergic (NANC) inhibitory neurotransmission in pyloric smooth muscle cells and exhibits sexual dimorphism, all of which have been linked to IPS. Somatostatin may have an influential role on gastrin and the development of a pyloric tumour.

Aim: The objective of this case controlled study was to compare fasting serum gastrin and somatostatin levels in IPS and control patients and to correlate the levels of the hormones.

Method: 39 children with IPS and 20 age-matched controls with no evidence of gastrointestinal disease were recruited. Fasting serum samples were collected, centrifuged immediately and stored a -70oC until analysis. Standard Radioimmunoassay Techniques were used to detect circulating levels of the hormones. A two-tailed t-test was used for statistical analysis.

Results: The median age of the study and control groups were 3.5 and 4.5 weeks respectively. The fasting gastrin levels were found to be comparable in IPS compared to controls (75.6, 68.1 ng/L respectively; p=0.353). The difference in the fasting somatostatin level was significant(38.9, 30.5 ng/L respectively; p=0.016). No correlation could be found between the levels of gastrin and somatostatin in the individual patients.

Conclusion: Fasting somatostatin levels and not gastrin levels are raised in IPS. Somatostatin is known to influence pyloric motility, and affect males and females differently. This study has identified a physiological link between hormonal and neurotransmitter theoriessurrounding the development of IPS.