Effects of short-term feeding of rats with a highly purified phaseolin preparation.

Rats fed a diet containing a highly purified preparation of phaseolin, the main globulin from the seeds of Phaseolus vulgaris, rapidly lost weight. Fecal nitrogen outputs were elevated and the N digestibility, based on conventional method estimation, was only 37.5%. By using immunological techniques, however, it was shown that the bulk of the nitrogen recovered in the feces was not chemically related to phaseolin. After correction for this non-phaseolin N, the true digestibility of phaseolin was estimated to be 74.3%. It is suggested that phaseolin and/or undigested fragments derived from the native molecule may, as reported for the lectins, stimulate the secretion of endogenous N, possibly mucins.