Possible Interaction: Insulin and Trypsin

“In human fat cells, on the contrary, trypsin failed to modify the antilipolytic effect of insulin , but markedly potentiated the lipolytic response to epinephrine, norepinephrine and isoproterenol.”

“In rat fat cells, trypsin abolished the antilipolytic effect of insulin but maintained a normal lipolytic response to epinephrine, norepinephrine and isoproterenol.”

“ Trypsin cleaves the N-terminus of PAP, which in turn forms insoluble fibrils.”

“However, secretion of trypsin , another pancreatic enzyme, interferes with insulin production in such systems.”

“Furthermore, with trypsin pretreatment, the plasma glucose level was reduced to less than 60% of the initial value after 8 h of in vivo permeation of bovine insulin with pH 3.0 solution, but did not return to the initial value during an 8-h experiment.”

“Mechanistic studies with Fourier transform-infrared and attenuated total reflectance analysis and electrical resistance measurements suggest that trypsin alters the SC protein structure from the alpha- to the beta-form and decreases the electrical resistance of skin, thereby decreasing the SC barrier and enhancing the permeation of insulin.”

“ Trypsin significantly increased the transdermal permeability of bovine insulin in pH 3.0 solution, but no effect was observed in pH 6.0 solution.”

“On the other hand, mild trypsin digestion of adipocytes decreases the glucose incorporation in the presence of 28.5 mU insulin , from 201 to 126% — whereas the effect of copper on glucose incorporation is the same in the trypsin-treated or untreated adipocyte.”

“Glucose oxidation was activated maximally by trypsin in 30 s and preceded maximal activation of glycogen synthase, which occurred in 60 s. Trypsin action to activate glycogen synthase was further enhanced by insulin.”

“Treatment of isolated heart cells with trypsin and β-galactosidase led to a decrease in specific binding of125I-labelled insulin.”

“In vitro exposure to trypsin results in the formation of insoluble fibrillar structures.”

“The use of an additional trypsinization step enhanced the findings obtained by simple removal of the culture medium: a clear stimulatory effect of insulin on TG synthesis was observed after both 24 and 48 hr of culture.”

“ Insulin treatment of adipocytes for 20 min prior to sequential additions of cyanide and trypsin caused a 16-fold increase in the proteolytically cleaved GLUT4 species.”