Segmental differences along the crypt axis in the response of cell volume to secretagogues or hypotonic medium in the rat colon.
VIP caused a decrease in the diameter of rat colonic crypts. This decrease was followed by a volume increase at the middle and the upper third of the crypt, which finally led to an increase of crypt diameter above the initial control values. At the fundus only a cell shrinkage was observed. The volume increase at the upper parts of the crypt was suppressed by the inhibitor of the Na(+)-K(+)-Cl(-)-cotransporter, furosemide. When crypts were exposed to a hypertonic medium, cell shrinkage was followed by a regulatory volume increase at the middle and the upper third of the crypt but not at the fundus region. These results suggest a gradient in the distribution of the Na(+)-K(+)-Cl(-)-cotransporter along the crypt axis.
Institut für Veterinär-Physiologie, Universität Zürich, Switzerland.
M
M
Diener
D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D002352:Carrier Proteins / Q000032:analysis / Q000502:physiology; D003106:Colon / Q000737:chemistry / Q000166:cytology* / Q000648:ultrastructure*; D005665:Furosemide / Q000494:pharmacology; D007038:Hypotonic Solutions / Q000494:pharmacology*; D008353:Mannitol / Q000494:pharmacology*; D008871:Microvilli / Q000737:chemistry / Q000502:physiology / Q000648:ultrastructure; D051381:Rats; D028021:Sodium-Potassium-Chloride Symporters; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D002352:Carrier Proteins; D007038:Hypotonic Solutions; D028021:Sodium-Potassium-Chloride Symporters; D014660:Vasoactive Intestinal Peptide; D008353:Mannitol; D005665:Furosemide; D002217:Carbachol