Islet Neogenesis-Associated Protein (INGAP)-Positive Cell Mass, B-Cell Mass and Insulin Secretion: Their Relationship During the Fetal and Neonatal Periods.

MADRID VG; BORELLI MI; MAIZTEGUI B; FLORES LE; GAGLIARDINO JJ; DEL ZOTTO H

PANCREAS.

LIPPINCOTT WILLIAMS & WILKINS

Lugar: Philadelphia; Año: 2013 vol. 42 p. 422 - 428

0885-3177

Objectives: To study the chronological appearance of pancreatic islet neogenesisYassociated protein (INGAP)-positive cells and its correlation with the increase in A-cell mass and function in fetal and neonatal rats. Methods: NormalWistar rat embryos (E) at gestational days 15, 17, and 19 (E15, E17, E19) and 7-day-old postnatal rats (P7) were humanely killed to determine body and pancreasweight; blood glucose; glucose and arginine-induced insulin secretion; real-time polymerase chain reaction of Pdx1 and Ngn3; quantitative immunomorphometric analysis of A-cell replication and apoptosis rate, cytokeratin and INGAP cell mass, and Pdx-1Y and Ngn3-positive cells. Results: Body and pancreas weight increased with age (P7 9 E19 9 E17 9 E15; P G 0.05). Neonates had higher blood glucose concentrations than embryos (P G 0.05). We recorded a simultaneous and significant age-dependent trend of increase in the number of A- and Pdx-1- positive cells, A- and cytokeratin-positive cell mass and A-cell capacity to release insulin in response to glucose and arginine, and decreased A-cell apoptotic rate. These changes closely paralleled the increase in INGAPpositive cell mass. Conclusions: These findings suggest that INGAP exerts a positive modulatory effect on A-cell mass and its secretory function in fetal and neonatal rats, thus becoming a new component in the multifactorial regulation of such processes.