The number of beta cells increased rapidly in early postnatal period and outnumbered the
alpha cells which got oriented at the peripheral region of the islet tissue.
Alcoholic, Mallory Heidenhain's Azocarmine Stain (X400) Alpha cells, B--Beta cells
Age 55 yrs., Non-Alcoholic, Haematoxylin Phloxine Stain (X400) Alpha cells, B--Beta cells
To test that hypothesis, the researchers tagged
alpha cells in mice, then killed their beta cells.
As compared to alpha cells, both rat and human beta cells expressed 2 times higher levels of enolase 1 (ENO1) and pyruvate kinase M2 (PKM2) isoform.
Rat Human Number of proteins Beta Alpha Endocrine Exocrine identified n [greater than or equal to] 1 506 417 462 372 Number of proteins quantified n [greater than or equal to] 2 465 353 413 300 GEO-normalized molar amount Highest 3.61 8.22 8.95 14.74 Lowest 0.02 0.02 0.01 0.06 Dynamic range 226 548 746 246 Biological replicates (x) 3 3 4 1 Technical replicates (n) 3 3 3 3 Unfractionated protein extracts of FACS-purified pancreatic beta and alpha cells (n = 3) and FACS-enriched human islet endocrine cells (n = 4) were analyzed by alternate-scanning LC-MS/MS.
Alpha cells have the opposite function of beta cells.
While the alpha cells cause the blood sugar level to rise, the beta cells ensure that it falls.
Alpha cells make glucagon, the hormone that raises blood sugar during fasting.
"We found that glutamate, a major signaling molecule in the brain and pancreas, is secreted together with glucagon by alpha cells and affects beta cell integrity," Dr.
The researchers say that the body then senses a loss of
alpha cells, replaces them with new
alpha cells, and then converts those too into beta cells.
The finding suggests that for people with either type 1 or type 2 diabetes, a therapeutic approach could be developed to target insulin receptors or proteins in
alpha cells in order to suppress glucagon secretion.
