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Dimethyl sulfoxide affects water flow through a nonosmolar action.
S Sabatini1, J C Wharton, H K Lim
1Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock.
Summary
Dimethyl sulfoxide (DMSO) affects cell membrane transport, but not solely through osmolality. This study shows DMSO enhances water flow in toad bladders, unlike mannitol or NaCl at higher concentrations.
Area of Science:
- Physiology
- Cell Biology
- Membrane Transport
Background:
- Dimethyl sulfoxide (DMSO) is a widely used solvent in membrane transport studies.
- Its effects on cell function are known, but the precise mechanism, particularly regarding osmolality, is not fully understood.
Purpose of the Study:
- To investigate the effects of serosal Dimethyl sulfoxide (DMSO) on basal and stimulated water flow in toad bladders.
- To differentiate DMSO's action from osmotic effects by comparing it with mannitol and NaCl.
Main Methods:
- Experiments were conducted on toad bladders using varying osmolar concentrations of DMSO, mannitol, and NaCl.
- Water flow was measured under basal conditions and after stimulation with vasopressin (AVP) and cyclic AMP.
- The influence of verapamil and dimethylsulfone was also assessed.
Main Results:
- All agents (DMSO, mannitol, NaCl) increased basal water flow at 300 mOsm.
- At higher concentrations (600-900 mOsm), DMSO enhanced vasopressin-stimulated water flow, while mannitol and NaCl decreased it.
- DMSO counteracted the inhibitory effect of verapamil on AVP-stimulated water flow, unlike mannitol.
Conclusions:
- The osmolar concentration of Dimethyl sulfoxide (DMSO) does not solely explain its effects on water transport.
- DMSO exhibits specific actions on membrane water permeability beyond simple osmotic pressure.
- These findings highlight a non-osmotic mechanism for DMSO's influence on cellular water movement.