Reversible inhibition by lanthanum of the hydrosmotic response to serosal hypertonicity in toad urinary bladder
| Autor: | Jacques J. Bourgoignie, Marcos A. Hardy, Peter Balsam |
|---|---|
| Rok vydání: | 1979 |
| Předmět: |
medicine.medical_specialty
Physiology Urinary Bladder Biophysics chemistry.chemical_element Biological Transport Active Toad Calcium In Vitro Techniques Serous Membrane Body Water Lanthanum biology.animal Internal medicine medicine Animals Reversible inhibition Urinary bladder integumentary system biology urogenital system Cell Biology Human physiology medicine.anatomical_structure Endocrinology chemistry Permeability (electromagnetism) Depression Chemical Bufo marinus hormones hormone substitutes and hormone antagonists Antidiuretic |
| Zdroj: | The Journal of membrane biology. 48(1) |
| ISSN: | 0022-2631 |
| Popis: | In the urinary bladder of amphibia, hypertonicity of the serosal bath (SH) evokes an increase in transepithelial water permeability, the characteristics of which resemble the response to antidiuretic hormone (ADH). The ionic dependency, in particular for Ca2+, appears very similar for SH- and ADH-induced water fluxes. In the present experiments La3+ was used as a probe to study the Ca2+-dependency of the hydrosmotic response to SH in isolated urinary bladder of the toad Bufo marinus. Addition of La3+ (5 mM) on the serosal side of the membrane produced a significant and reversible increase in basal transepithelial water flux. The hydrosmotic response elicited by adding 250 mM mannitol to the serosal Ringer's solution was inhibited by 30% in the absence of serosal Ca2+. Similarly, the hydrosmotic response to SH was inhibited by 37%, 30% and 40% when 5 mM La3+ was added to the serosal medium 30 min before, concommitantly with, or 60 min after induction of SH. The inhibition of transepithelial water flux observed in the absence of serosal Ca2+ or in the presence of serosal La3+ was reversible. The results support a critical role for Ca2+ in the modulation of transepithelial water permeability in the urinary bladder of amphibia. Ca2+ presumably exerts its effects at a post-cyclic AMP step. |
| Databáze: | OpenAIRE |
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