title: Immunocytochemical localization of peptides in the endocrine pancreas of the snakes Vipera aspis and Natrix maura.
abstract: The endocrine pancreas of Vipera aspis and Natrix maura has been investigated by immunocytochemistry for the presence of six peptides reported to occur in Mammals or in Reptiles. Gastrin/CCK and PP were absent in the endocrine cells, VIP was located within nerve terminals only. Insulin, Glucagon, and Somatostatin were localized both in Vipera and Natrix, generally with a ring of D (Somatostatin) cells surrounding a core of Glucagon (A) and Insulin (B) producing cells; however frequent clusters of D cells are intermingled with the other endocrine cells. Statistical evaluations on the percentages of these 3 cell types showed preponderance of A cells in Natrix whereas in Vipera no significant difference was found between the number of A and B cells. The D cells showed a uniform distribution in the pancreas of the 2 studied species, in any case with a percentage slightly inferior to those of B cells.
authors.affiliation: Institute of Comparative Anatomy, University of Genova, Italy.
authors.forename: M A
authors.initials: MA
authors.lastname: Masini
mesh_terms: D000818:Animals; D002766:Cholecystokinin / Q000032:analysis; D005755:Gastrins / Q000032:analysis; D005934:Glucagon / Q000032:analysis; D006728:Hormones / Q000032:analysis*; D007150:Immunohistochemistry; D007328:Insulin / Q000032:analysis; D007515:Islets of Langerhans / Q000166:cytology*; D008297:Male; D010191:Pancreatic Polypeptide / Q000032:analysis; D010455:Peptides / Q000032:analysis*; D012911:Snakes / Q000378:metabolism*; D013004:Somatostatin / Q000032:analysis; D013045:Species Specificity; D014660:Vasoactive Intestinal Peptide / Q000032:analysis
chemical_list: D005755:Gastrins; D006728:Hormones; D007328:Insulin; D010455:Peptides; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin; D010191:Pancreatic Polypeptide; D005934:Glucagon; D002766:Cholecystokinin