Plasma radioimmunoassayable neurotensin responses to the administration of various nutrients.

In order ot elucidate the releasing mechanism of gut neurotensin, plasma radioimmunoassayable neurotensin (RNT) was measured in dogs after intrajejunal administration of various nutrients. Transient and slight increases of plasma RNT were found after administration of glucose and saturated fatty acid. In contrast, remarkably raised plasma RNT levels were seen after administration of an amino acid mixture and of unsaturated fatty acid. The findings suggested that gut neurotensin may play roles in digestion and absorption of amino acid and some fatty acids.