Journal of Dental Research, Vol 65, 673-676, Copyright © 1986 by International & American Associations for Dental Research Online Journals
A comparison of some of the permeability characteristics of intact and tape-stripped hamster cheek pouches in vitro
C. O. Reid, J. Hardcastle and C. J. Smith
Cheek pouches were removed from anesthetized hamsters and were either
tape-stripped or left intact and then mounted in Ussing chambers, where
they were bathed in Krebs-Ringer bicarbonate saline. A potential difference
could be measured across all pouches and was stable for over an hour across
the unstripped pouches. The electrical resistance across the unstripped
pouches was high (8960 omega.cm2), whereas the resistance across the
tape-stripped pouches was significantly lower (p less than 0.01),
suggesting that these pouches are likely to be more permeable than the
unstripped pouches. Reflection coefficients of urea, ethanol, and glycerol
were derived by means of streaming potentials. Values for intact pouches
were all close to 1 and for tape-stripped pouches were 0.938, 0.822, and
0.509, respectively. Permeability coefficients for urea and ethanol across
intact and tape-stripped pouches were, respectively, 12.5 X 10(-9)cm/min;
27.6 X 10(-9) cm/min; 2325 X 10(-9)cm/min; and 28471 X 10(-9) cm/min. The
hamster cheek pouch has a high electrical resistance; it is an impermeable
structure in which the keratin layer appears to provide a major barrier to
the passage of water, ions, and certain solutes.
