HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ackrill, P. Articles by Thomas, S. Search for Related Content PubMed PubMed Citation Articles by Ackrill, P. Articles by Thomas, S.

1. A comparison was made of various transport properties and electron-microscopical characteristics of isolated urinary bladders from toads (Bufo bufo) maintained in either tap water or 0·7% saline (0·7 g NaCl in 100 ml. H₂O) for 10 days to 2 months.

2. In the absence of Pitressin, isolated bladders from saline-adapted toads showed:

(a) markedly, and significantly, lower osmotic water flow;

(b) moderately, but not significantly, lower urea permeability;

(c) no significant change in net sodium transport (measured as short-circuit current, I_sc); and

(d) significantly smaller intercellular space/mucosal cell ratios in electron-micrographs.

3. Differences in the transport and electron-microscopical characteristics between bladders from water-exposed and saline-adapted toads became more evident in the presence of exogenous Pitressin (10 m-u./ml. serosal solution):

(a) the stimulating influence of Pitressin on osmotic water flow, short-circuit current and urea permeability was considerably smaller in bladders from saline-adapted toads than in those from water-exposed toads;

(b) the influence of Pitressin on short-circuit current was reduced more profoundly than that on either water flow or urea permeability;

(c) the Pitressin-induced increment in intercellular space/mucosal cell ratio was significantly smaller in electron-micrographs of bladders from saline-adapted toads than in those from water exposed toads.

4. The effects of saline adaptation are discussed in relation to decreased permeability of mucosal membrane barriers.