Effect of annexin I on insulin secretion through surface binding sites in rat pancreatic islets.
This study investigates the effect of extracellular annexin I (Anx I) on regulating insulin secretion in isolated rat pancreatic islets. Results show that Anx I stimulates insulin release in pancreatic islets regardless of the presence or absence of extracellular Ca2+. In particular, confocal microscopy shows that Anx I binds to the surface of islet cells in the absence of extracellular Ca2+. However, insulin secretion through Anx I significantly decreases in trypsin-treated islets. Likewise, there is minimal binding of Anx I to the surface of trypsin-treated islets. Anti-Anx I polyclonal antibody also inhibits the stimulating effect of Anx I on insulin secretion. These results indicate that Anx I is capable of binding to the cell surface receptor, in order to regulate the stimulation of insulin release in rat pancreatic islets.
Hong
Shin-Hee
SH
Department of Biological Sciences, SungKyunKwan University, Suwon 440-746, South Korea.
Won
Jong Hak
JH
Yoo
Seung-Ah
SA
Auh
Chung-Kyoon
CK
Park
Young Min
YM
D000818:Animals; D017305:Annexin A1 / Q000378:metabolism* / Q000494:pharmacology*; D000906:Antibodies / Q000494:pharmacology; D001665:Binding Sites; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005947:Glucose / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014357:Trypsin / Q000494:pharmacology
D017305:Annexin A1; D000906:Antibodies; D007328:Insulin; D014357:Trypsin; D005947:Glucose