Abstract
The responses to mucosal pressure elevation (physiological pressure: PP) were compared to responses to serosal pressure elevation (non-physiological pressure: NPP) in bullfrog urinary bladders (Rana catesbeiana). The bladders were mounted on vertical chambers as flat sheets. Distension was applied with 98.07 Pa. pressure gradients. PP resulted in increases in transepithelial electrical potential difference (TEP) and short-circuit current (SCC). Electrical resistance (R), urea permeability (Purea) and net water flux (Jv) were not effected. NPP resulted in decreases in TEP (38%), SCC (13%), and R (36%). While Purea (97%) and Jv (96%) increased. PP caused little or no change in the electron microscopic structure of frog bladder while NPP caused irreversible dilation of the lateral intercellular spaces. There were no observable changes in tight junctions under PP or NPP. The subepithelial elements of the bladder became detached from the epithelial layer during NPP suggesting a role for them during PP.
Original language | English (US) |
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Pages (from-to) | 405-414 |
Number of pages | 10 |
Journal | Archives of Physiology and Biochemistry |
Volume | 108 |
Issue number | 5 |
DOIs | |
State | Published - 2000 |
Externally published | Yes |
Keywords
- Amphibia
- Epithelial structure
- Epithelial transport
- Osmotic flux
- Short-circuit current
- Urea permeability
ASJC Scopus subject areas
- Physiology
- Physiology (medical)