Boiling method for the extraction of gut glucagon-like immunoreactive materials

The boiling method deviced in accordance with the extraction procedure of secretin was applied to the extraction of gut glucagon-like immunoreactive material (GLI) and compared with the acid alcohol method of Kenny with respect to efficiency of the extraction and property of the extracted materials. GLI was extracted from minced porcine small intestine by each method. The total amount of GLI extracted by the boiling method was 14.45+/-2.07 mug/10g small intestine (mean+/-SE), showing a high yield as compared to 4.07+/-0.29 mug/10 g small intestine obtained by the acid alcohol method. The difference was statistically significant (p less than 0.005). The gel chromatogram of the acid alcohol extract was separated into two peaks; peak 1 appeared before the the insulin marker, while peak II was eluted with the glucagon marker. The chromatogram of the boiling extract has a main broad fraction including insulin marker and a minor second peak corresponding to peak II of the acid alcohol extract. Boiling of the acid alcohol extract did not cause any shift of peak I in chromatogram. GLI present in the first half of the main fraction of the boiling extract was different from that in the latter half, but identical to peak I of the acid alcohol extract with respect to the immunoreactivity against glucagon antibody. It is concluded that in the extraction of GLI not only high yield is achieved but one or more new components is picked up by the boiling procedure as compared to the acid alcohol method.