Immunocytochemical evidence for the presence of S-100 protein in insulin-containing cells of cultured fetal rat islets.
S-100 protein was long considered to be specific to glial and Schwann cells, but was subsequently proved to be present in various organs. In particular, S-100 proteinimmunoreactivity was demonstrated in the parathyroid gland, adenohypophysis and endocrine pancreas. In the present study cultured fetal rat islets were investigated in view of the possible presence of S-100 protein immunoreactivity in their cells. In the initial 5-day period, continuity between islets and ducts could be demonstrated, and the islets appeared to bud from the ducts. During this time, S-100 protein-immunoreactive cells were found in either the budding islets or ducts. The colocalization of S-100 protein and insulin was demonstrated immunocytochemically. In contrast, the newly formed islets from endocrine monolayers did not display S-100 protein immunoreactivity. After this initial period, numerous free-floating islets were observed, but only some of them contained S-100 protein immunoreactivity. S-100 protein-immunoreactive cells had the same distribution as those storing insulin, again suggesting the coexistence of the two peptides. The results suggest that S-100 protein might be involved in the regulation of islet function.
Leduque
P
P
CNRS UA 559, Faculté de Médecine Lyon-Sud, Oullins, France.
Scharfmann
R
R
Basmaciogullari
A
A
Czernichow
P
P
Dubois
P M
PM
D000818:Animals; D002478:Cells, Cultured; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D007515:Islets of Langerhans / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D009418:S100 Proteins / Q000032:analysis*
D005904:Glial Fibrillary Acidic Protein; D007328:Insulin; D009418:S100 Proteins