EFFECTS OF VASOPRESSIN, CYCLIC AMP, AND THEOPHYLLINE ON OXYGEN CONSUMPTION OF TOAD BLADDER 'SACS'

in Journal of Endocrinology
Authors:
M. PARISI
Search for other papers by M. PARISI in
Current site
Google Scholar
PubMed
Close
and
P. J. BENTLEY
Search for other papers by P. J. BENTLEY in
Current site
Google Scholar
PubMed
Close
Restricted access
Rent on DeepDyve

Sign up for journal news

SUMMARY

The oxygen consumption of toad urinary bladders was lower in preparations made up as sacs than in pieces of tissue freely suspended in Ringer solution.

Vasopressin stimulated uptake of oxygen by both types of preparation. This probably reflects facilitated sodium transport from the mucosal to serosal side of the tissue since exclusion of this ion from the fluid bathing the mucosa (inside) abolished this effect.

When water transfer across the bladder is promoted by vasopressin (in the presence of an osmotic gradient; inside hypo-osmotic) there is a reduction (by about 50%) in usage of oxygen. Cyclic AMP had a similar action.

Theophylline and cyclic AMP failed to influence oxygen uptake by pieces of toad bladder tissue freely bathed in sodium—Ringer solution. In preparations made as sacs containing iso-osmotic sodium—Ringer solution the nucleotide stimulated while, paradoxically, the xanthine depressed oxygen consumption. This action of cyclic AMP (like that of vasopressin) is dependent on the presence of sodium at the mucosal side of the tissue since it is not seen in sacs filled with choline—Ringer solution. However, the reduction in O2 consumption produced by theophylline was still seen in the absence of sodium.

 

  • Collapse
  • Expand