[Lys0] - γ - 1 - MSH (41 - 58), amide

4-Methylumbelliferyl-α-D-Glucopyranoside (4-Methylumbelliferyl-α-D-Glucose) is a fluorescent substrate for α-glucosidase, which releases the fluorescent moiety 4-methylumbelliferyl (4-MU) upon cleavage. 4-MU has pH-dependent fluorescence excitation activity, with excitation wavelengths of 320 nm at low pH (1.97-6.72) and 360 nm at high pH (7.12-10.3), respectively. The emission wavelength of 4-Methylumbelliferyl-α-D-Glucopyranoside increases with decreasing pH, ranging from 445-455 nm. 4-Methylumbelliferyl-α-D-Glucopyranoside can be used as a biomarker for Fabry and Pompe diseases to quantify α-glucosidase activity in infant blood spot samples.

Gastrin-releasing peptide is a regulatory human peptide that elicits gastrin release and regulates gastric acid secretion and enteric motor function. The post-ganglionic fibers of the vagus nerve that innervate the G cells of the stomach release GRP, which stimulates the G cells to release gastrin.