Involvement of renin-angiotensin system in pressure-flow relationship: role of angiotensin-converting enzyme gene polymorphism.
BACKGROUND
The renin-angiotensin system is involved in blood pressure regulation. The insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene is known to be associated with variation of plasma and cellular ACE concentrations. Furthermore, changes in arterial function have been suggested to be associated to the DD genotype. The aim of the study was to investigate the arterial vascular response to a physiologic stimulus (i.e., flow) according to the I/D ACE gene polymorphism.


METHODS
Sixty patients scheduled for coronary artery bypass grafting (n = 24) or valve surgery (n = 36) under normothermic cardiopulmonary bypass were genotyped in a blind manner by polymerase chain reaction. Mean arterial pressure was measured at pump flows ranging from 1 to 3 l x min(-1) x m (-2) by 0.25 l x min(-1) x m(-2) step each 15 s, to obtain a pressure-flow relation. Independent factors associated with the variation of the slope of the pressure-flow relation curve were assessed by multivariate analysis.


RESULTS
We found a D allelic frequency of 0.54. Patients were separated in two groups (DD, n = 16; ID/II, n = 44). There were no significant difference with regard to preoperative and intraoperative data between the two groups. DD patients had their pressure-flow relation curves shifted upward (with higher pressures as flow increased), indicating a lesser decrease in vascular resistance. Furthermore, DD genotype was the only independent predictor of the slope of the curves (21.5 +/- 4.2 vs. 18.1 +/- 5 mmHg/[l x min(-1) x m(-2)] for DD and ID/II, respectively; P = 0.02; values are mean +/-SD).


CONCLUSIONS
These results show that vasomotor properties are influenced by the I/D polymorphism of the ACE gene.
Lasocki
Sigismond
S
Département d' Anesthésie-Réanimation, Hôpital Bichat, Paris, France.
Iglarz
Marc
M
Seince
Pierre-François
PF
Vuillaumier-Barrot
Sandrine
S
Vicaut
Eric
E
Henrion
Daniel
D
Levy
Bernard
B
Desmonts
Jean-Marie
JM
Philip
Ivan
I
Bénessiano
Joelle
J
D000368:Aged; D000758:Anesthesia; D001794:Blood Pressure / Q000502:physiology*; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D003326:Coronary Circulation / Q000502:physiology; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000235:genetics*; D011110:Polymorphism, Genetic; D012084:Renin-Angiotensin System / Q000502:physiology*; D014655:Vascular Resistance / Q000502:physiology*
D007703:Peptidyl-Dipeptidase A