An immunocytochemical study of the cytogenesis of pancreatic endocrine cells in the lizard, Anolis carolinensis

Abstract

The differentiation of the pancreatic endocrine cells in the lizard Anolis carolinensis following oviposition was examined. Immediately postoviposition (PO) there was no apparent differentiation of epithelioid cells into endocrine or exocrine components. Individual subpopulations of the endocrine-like cells, which could not be identified during the early PO period on the basis of either their tinctorial properties at the light-microscopic level or their granule morphologies at the electron-microscopic level, exhibited specific hormonal localization by peroxidase-antiperoxidase complex immunocytochemistry. All four hormones searched for, insulin, glucagon, somatostatin, and pancreatic polypeptide (PP), were present in epithelioid cells shortly after oviposition. However, the immunostained secretory granules in the early PO period were smaller than those of the adult. Secretory granule morphologies that are typical of the adult were acquired at different times during development. Delta granules were observed first and were followed by alpha granules, and beta granules which appeared shortly before birth. The secretory granules of the PP-containing F cells could not be readily placed within this maturation sequence. Mosaic cells (containing more than one hormone) were not seen. Levels of immunoreactive insulin and glucagon in the pancreas increased several fold from day 10 to day 28 PO, but the attainment of adult beta-granule morphologies did not appear to be directly related to insulin itself. The results show that cytodifferentiation of the anolian endocrine pancreas occurs postoviposition and that immunocytochemical methods can be used to follow an organelle sequence during development. These findings suggest that subcellular organelles undergo structural remodeling during maturation which, at least in the case of secretory granules, may have functional significance.

Continuous‐Perifusion tissue culture of fetal and adult pancreas of the lizard Anolis carolinensis

“…As reported recently (Rhoten and Hall, 19811, the secretory granules of the PP-containing F cells of the adult anole cannot be identified with certainty, especially with regard to the secretory granules of the D cells, unless immunocytochemical techniques are used. The small, elliptic and electron-dense granules that were occasionally observed in the cultured explants appear to be similar to those found in the endocrine-like cells during the early postoviposition period (Rhoten and Hall, 1982). Cells with these small, electron-dense granule profiles are found rarely in the adult and in the cultured adult pancreas.…”

“…The cages of the gravid females were examined at least four times daily for eggs. The eggs were incubated on gauze wicks at 28 rn 2°C wet bulb as described previously (Rhoten and Hall, 1982).…”

The distribution and frequency of endocrine cells in the splenic lobe of grass lizard (Takydromus wolteri): An immunohistochemical study

“…The distribution and frequency of endocrine cells in the splenic lobe of grass lizard (Takydromus wolteri): An immunohistochemical study frequency of major four types of endocrine cells, insulin, glucagon, somatostatin and PP, were reported in the lizard pancreas such as lacertid lizards (Della Rossa and Putti, 1995), desert lizard (Chalcides ocellatus and Uromasyx aegyptia) (ElSalhy and Grimelius, 1981;El-Salhy et al, 1983), green anole (Anolis carolinensis) (Rhoten and Hall, 1982) and grass lizard (Mabuya quinquetarniata) (El-Salhy and Grimelius, 1981) . In addition, peptide tyrosine tyrosine-and neuropeptide tyrosine-(Della Rossa and Putti, 1995) and chromogranin (CG)- (Trandaburu et al, 1999) IR cells were found in the lacertid lizard pancreas and new types of endocrine cells have been reported in the pancreas of the various vertebrates.…”

The Endocrine Pancreas of the Lizard Calotes versicolor: An Immunocytochemical and Physiological Study with Respect to its Reproductive Cycle

“…Histological and immunohistochemical investigation of endocrine pancreas of the grass lizard, Mabuya quinquetaeniata, and that of the desert lizard, Uromastyx aegyptia was reported [3]. Rhoten and Hall [4] examined the differentiation of islets of Langerhans in the lizard Anolis carolinensis. The endocrine pancreas of the lizard, Podarcis hispanica, consists of single scattered cells or small groups of two to five cells forming islet-like structures [5].…”