LOCALIZATION OF AQUAPORIN-1 IN THE SMALL AND LARGE INTESTINES OF GEESE (Anser anser)

Abstract

Aquaporins are selective water channels that serve transportation of water across cell membranes, which play a vital role in all cells. In this study, using the immunohistochemical method, the authors intended to investigate the localization of Aquaporin-1 in the small and large intestines of geese. In this study, small and large intestine tissue samples taken from healthy adult geese (Anser anser) (n = 10) were used as materials. After fixation for 24 hours at 10% formaldehyde, the tissue samples were passed through graded series of ethanol and xylol and embedded in paraffin. Mallory's modified triple-staining method was used to examine the general structure of the intestine. The Avidin-Biotin-Peroxidase Complex (ABC) method was applied to determine the immunoreactivity of Aquaporin-1. The apical parts of crypt epithelial cells showed dense Aquaporin-1 immunoreactivity in the duodenum and moderate Aquaporin1 immunoreactivity in the jejunum and ileum. Strong Aquaporin-1 immunoreactivity was determined in vascular endothelial cells in the duodenum, jejunum, and ileum, and weak immunoreactivity was found in smooth muscle cells. However, a weak Aquaporin-1 immunoreactivity was detected only in the smooth muscle cells of the cecum and rectum but not in vascular endothelial cells and crypt epithelial cells. The intestine tissue regulates salt transport and hydrostatic pressure differences, enabling the transportation of water. It was suggested that the duodenum and jejunum sections in particular are permeable to high levels of water for balancing the osmotic pressure of the intestinal content. Consequently, with this study, Aquaporin-1 immunoreactivity was detected in the crypt epithelial cells, smooth muscle cells, and vascular endothelium of the small intestines of geese. Lokalizacija akvaporina-1 v tankem in debelem črevesu pri goseh (Anser anser) Izvleček: Akvaporini so selektivni vodni kanali za prenos vode skozi celične membrane in imajo pomembno vlogo v vseh celicah. V tej študiji smo z imunohistokemično metodo ugotavljali mesto nahajanja akvaporina-1 v tankem in debelem črevesju gosi. Uporabili smo vzorce (n = 10) tankega in debelega črevesa odraslih, zdravih gosi (Anser anser). Po 24 urni fiksaciji v 10% formaldehidu smo vzorce dehidrirali v zaporednih stopnjah etanola in ksilola ter jih vpeli v parafin. Za pregled splošne strukture črevesa smo uporabili Malloryjevo modificirano metodo trojnega barvanja. Za določanje imunoreaktivnosti akvaporina-1 je bila uporabljena metoda kompleksa avidin-biotin-peroksidaza (ABC). Močno imunoreaktivnost akvaporina-1 smo ugotovili na apikalnih delih epitelijskih celic kript dvanajstnika ter žilnih endotelijskih celicah v dvanajstniku, jejunumu in ileumu. Zmerna imunoreaktivnost akvaporina-1 je bila prisotna v jejunumu in ileumu. Imunoreaktivnost je bila šibka v celicah gladkih mišic, vendar le v celicah slepega črevesa in danke, ne pa tudi v žilnih endotelijskih celicah in epitelijskih celicah kripte. Črevesno tkivo omogoča prenos vode z uravnavanjem prenosa soli in razlik v hidrostatičnem tlaku. Predpostavljeno je, da sta zlasti odseka dvanajstnika in jejunuma prepustna za velike količine vode za namen uravnavanja osmotskega tlaka črevesne vsebine. Posledično je bila tudi v tej študiji ugotovljena imunoreaktivnost akvaporina-1 v epitelijskih celicah kript, gladkih mišičnih celicah in žilnem endoteliju tankega črevesa gosi. Ključne besede: gosi;  črevo; akvaporin-1