Endothelin-1: increased plasma clearance, pulmonary affinity and renal vasoconstriction in young smokers.
Pulmonary and renal haemodynamics and elimination of endothelin-1 (ET-1) were studied in six young smokers in response to 20 min intravenous infusion of ET-1 (4 pmol kg(-1) min(-1)) after smoking. At 20 min of ET-1 infusion fractional ET-1 extractions in the lungs and kidneys were 60 +/- 2 and 60 +/- 7%, respectively. Cardiac output and renal blood flow (RBF) fell by 18 +/- 4% (P<0.05) and 34 +/- 5% (P<0.01). Mean systemic arterial pressure increased (P<0.05) whereas pulmonary pressures were unchanged. Compared with previously published data in non-smokers (Weitzberg et al., 1991, 1993) basal arterial ET-1 and ET-1-values during ET-1 infusion were lower with a more rapid return to basal value. Smokers had higher pulmonary extraction of ET-1 at the same pulmonary arterial concentration (P<0.05). RBF reduction was more pronounced (P<0.05). Systemic vascular resistance increased while pulmonary vascular resistance did not increase as in non-smokers. Increased plasma clearance and more efficient pulmonary elimination of ET-1 lowers the arterial level in young smokers. In addition ET-1 evokes more pronounced renal vasoconstriction in these individuals.
Ahlborg
G
G
Department of Medical Laboratory Sciences and Technology, Division of Clinical Physiology, Huddinge University Hospital, Huddinge, Sweden. gunvor.ahlborg@labtek.ki.se
Lundberg
J M
JM
D000328:Adult; D000367:Age Factors; D002302:Cardiac Output; D019332:Endothelin-1 / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006439:Hemodynamics; D006801:Humans; D007262:Infusions, Intravenous; D007668:Kidney / Q000098:blood supply*; D008168:Lung / Q000098:blood supply*; D008297:Male; D012039:Regional Blood Flow; D012907:Smoking / Q000009:adverse effects*; D014661:Vasoconstriction / Q000187:drug effects*
D019332:Endothelin-1