Absence of vitamin B12-binding proteins in the histamine-containing gastric carcinoid in Praomys (Mastomys) natalensis.

The transplantable argyrophilic gastric carcinoids producing histamine found in Praomys (Mastomys) natalensis contained no significant amount of vitamin B12-binding proteins. It was also demonstrated that the concentration of vitamin B12-binding proteins in glandular stomach of mastomys was much lower than those in the same tissues of the rat or mouse.