The influence of sorbitol on the glycogenolytic pathway

The following report presents the results of a study conducted on the influence of sorbitol on levels of glycogen, phosphorylase a (E.C. 2.4.1.1.) and phosphorylase kinase (E.C.2.7.1.38) in slices of rat liver. In addition, it presents data concerning the effects of sorbitol on the activities of phosphorylase a and phosphorylase kinase purified from rabbit muscle. The data reveal a limitation in the glycogenolytic process which seems, in part, due to the inactivation of the phosphorylase a and phosphorylase kinase. Gel-filtration techniques showed, in fact, a breakdown of these two oligomeric enzymes into inactive subunits following incubation with sorbitol.