Nitric oxide and endothelin concentrations during intravenous infusion of urological irrigating fluid.
OBJECTIVE
To study the possible role of two vasoactive mediators, nitric oxide (NO) and endothelin, in the hemodynamic alterations following absorption of irrigating fluid.


METHODS
Twelve male volunteers received an intravenous administration of 1.5% glycine, given at a rate of 0.5 ml/kg/min for 30 min. Infusions of 3% mannitol served as controls. Blood pressure, heart rate and the plasma levels of endothelin and nitrite/nitrate (an index of NO activity) were measured before, during and after the infusions.


RESULTS
The endothelin concentration at baseline correlated inversely with the systolic arterial pressure (p<0.01). No qualitative differences were found between the two fluids with respect to the NO and endothelin responses, but the observed variations indicated the role of the two fluids during volume loading. In general, an elevation of blood pressure during the infusions was associated with an increase in the endothelin concentration, while a sustained elevation 30 min later was accompanied by a decrease in the NO activity. Reductions in the blood pressure and heart rate were associated with decreased NO concentrations.


CONCLUSIONS
The endothelin/NO axis may increase blood pressure in response to volume loading; it also acts to stabilize the circulation at baseline and probably also when the blood pressure decreases.
Department of Urology, Huddinge University Hospital, Huddinge, Sweden.
Lars
L
Sandfeldt
Hans
H
Gyllenhammar
Robert G
RG
Hahn
D000328:Adult; D004234:Diuretics, Osmotic / Q000008:administration & dosage / Q000494:pharmacology; D016232:Endothelins / Q000097:blood*; D005998:Glycine / Q000008:administration & dosage* / Q000494:pharmacology*; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008353:Mannitol / Q000008:administration & dosage / Q000494:pharmacology; D009569:Nitric Oxide / Q000097:blood*; D012016:Reference Values; D007507:Therapeutic Irrigation; D013997:Time Factors; D014570:Urologic Diseases / Q000097:blood* / Q000503:physiopathology / Q000601:surgery*; D013521:Urologic Surgical Procedures, Male; D014665:Vasodilator Agents / Q000097:blood*
D004234:Diuretics, Osmotic; D016232:Endothelins; D014665:Vasodilator Agents; D009569:Nitric Oxide; D008353:Mannitol; D005998:Glycine