Morphological adaptations to induced changes in transepithelial sodium transport in chicken lower intestine (coprodeum): a study of resalination, aldosterone stimulation, and epithelial turnover.
Transepithelial sodium transport and epithelial morphology during short-term adaptation to resalination or aldosterone stimulation were studied in the chicken coprodeum. Coprodeum was sampled for light and electron microscopy after 0-3 days of resalination in hens on a low-NaCl diet and after 0-6 days of aldosterone stimulation in hens on a high-NaCl diet. Sodium transport was measured in vitro with Ussing chambers. Plasma osmolality and electrolyte concentrations were measured in aldosterone-stimulated hens. Epithelial proliferation and migration between 1 h and 16 days were investigated in chickens on high-NaCl and low-NaCl diets using a bromodeoxyuridine technique. Resalination abolished the otherwise high sodium transport within 1 day, while the height and number of microvilli, as well as the number of brush cells, decreased over 3 days. Aldosterone stimulation increased sodium transport, the height and number of microvilli, and the brush-cell number. Bromodeoxyuridine studies indicated an epithelial cell turnover of more than 16 days. The results thus demonstrate that epithelial cells have an unusual capacity to adjust rap- idly to variations in sodium intake. A strong correlation between structure and function was apparent.
Elbrønd
V S
VS
Department of Anatomy and Physiology, The Royal Veterinary and Agricultural University, Bülowsvej 13, DK-1870 Frederiksberg C, Denmark. Vibeke.S.Elbroend@iaf.kvl.dk
Skadhauge
E
E
Thomsen
L
L
Dantzer
V
V
D000450:Aldosterone / Q000097:blood*; D000818:Animals; D000963:Antimetabolites; D001692:Biological Transport / Q000502:physiology; D001973:Bromodeoxyuridine; D002455:Cell Division / Q000502:physiology; D002645:Chickens; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D005260:Female; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000737:chemistry / Q000166:cytology; D008854:Microscopy, Electron; D012965:Sodium Chloride / Q000032:analysis / Q000378:metabolism*
D000963:Antimetabolites; D012965:Sodium Chloride; D000450:Aldosterone; D001973:Bromodeoxyuridine