Abstract
Fluid and solute movements across rabbit distal colonic mucosa were investigated to determine the solute concentration of the absorbate and to characterize the absorption process. With isotonic mucosal and serosal bathing solutions the osmolality of the absorbate was 492 +/- 22 mosmol/kg. When the absorbate concentration was corrected for passive components of water and salt flux, the concentration of the "active" component was 1,062 +/- 206 mosmol/kg. Octanol (2 mM) caused a decrease in net solute and water absorption and in the concentration of the absorbate. Cytochalasin D (20 microM) increased the absorbate tonicity and decreased the hydraulic conductance of the active route for water movement. Correlations were made with measurements of the total crypt and crypt luminal cross-sectional areas. Ouabain, octanol, deoxycholate, and theophylline increase the cross-sectional area of the crypt lumen relative to that of the total crypt. These findings suggest that the hypertonic component of fluid absorption is via the crypts. The large osmotic pressure across the crypt wall could provide the considerable fluid tension (5 atm) required to dehydrate feces.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: American Journal of Physiology-Gastrointestinal and Liver Physiology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
