Abstract
The extractability of neurotensin (NT) from porcine ileal mucosa was evaluated by comparison of eight extraction procedures. Concentrations of NT like immunoreactivities in the mucosa were quantitated and characterized by three sequence-specific radioimmunoassays and gel-chromatography. Tissue levels of intact NT were highest after extraction with boil following homogenization in 2.0M acetic acid (79.1±16.4pmol/g) and lowest after extraction with that in distilled water (6.5±1.4pmol/g). The opposite was the case with levels of N-terminal immunoreactivities (55.2±8.8pmol/g and 105.7±23.8pmol/g, respectively).
Recovery studies with addition of synthetic NT1-13 and NT1-8 indicated that these differences could be explained by differences in recovery of intact NT and N-terminal immunoreactive fragments in tissue.
In conclusion, this study showed that extraction procedures influence quantitative measurements of NT in ileal mucosa, and that 2.0M acetic acid is preferable when studying intact NT, distilled water is preferable when studying N-terminal fragments, respectively. Therefore, different extraction procedures may be necessary to extract NT like immunoreactive components from tissues.
