Immunolocalization of hexose transporters in ostriches' intestinal epithelial cells during their first postnatal week

Abstract

Although hexoses glucose and fructose serve as important energy sources of food, up to now, there is little information about hexose transporters in birds’ intestinal epithelium during their first postnatal week. The aim of the investigation was to carry out an immunohistochemical study of integral membrane proteins glucose transporter-2 and -5 (GLUT-2 and GLUT-5) on intestinal epithelial cells of ostrich chicks during their first postnatal week. The material from duodenum and ileum was collected from 9 female ostriches (Struthio camelus var. Domesticus) divided into three age groups, three birds in each group: chicks immediately after hatching, 3-day-old ostriches and 7-day-old chicks. The material was fixed in 10% formalin, embedded into paraffin, slices 7μm thick were cut followed by immunohistochemical staining with polyclonal primary antibodies Rabbit anti- GLUT-2 and Rabbit anti-GLUT-5, carried out according to the manufacturer’s guidelines (IHC kit, Abcam, UK). Immunohistochemical localization of GLUT-2 and -5 in the intestinal epithelial cells in ostriches of different age groups was determined. In the groups of chicks after hatching and 3-day-old ostriches, enterocytes in duodenal epithelium were mostly unstained and goblet cells stained weakly for both antibodies. Weak staining of enterocytes and goblet cells was also noted in the ileal epithelium of the chick after hatching. Moderate staining of goblet cells was noted in the 3-day-old chicks’ ileal epithelium. In 7-day-old ostriches, the expression of both antibodies was weak in duodenal but moderate in ileal epithelial cells. The pattern of immunohistochemical expression of GLUT-2 and GLUT-5 in ostriches’ intestinal epithelial cells confirms our hypothesis that the intestinal tract of ostriches after hatching is not yet entirely capable of transportation of hexoses and showed that it is completing gradually during the first postnatal week.