[Application of ultrasono-micrometric technic to study vasomotility].
An experimental model of simultaneous recording of pressure and flow (instantaneous and mean values) and of the vascular diameter (by ultrasonomicrometry) at the entry of a clearly limited territory of the systemic circulation has been developed in the animal together with a programme of data aquisition and analysis. This programme allows quantification of the different viscoelastic properties of the vessel wall which characterise arterial flow in the arteries of distribution (capacitance vessels) and irrigation (resistance vessels). The model was applied to the study of the pharmacological effects of two antianginal agents, a nitrate derivative (ND) administered acutely by slow intravenous infusion at a dose of 25 micrograms/Kg/mn over 20 minutes (total dose: 500 micrograms/Kg) and a substitute sydronimous substance (SYD) administered in the same manner at a dose of 15 g/Kg/mn over 20 minutes (total dose: 300 micrograms/Kg). The hypotensive effects obtained were comparable and significant (p less than 0.001) in both cases. The ND led to a fall in mean blood pressure of 9.7 +/- 1.3% and SYD of 10.0 +/- 2.1%. However, SYD led to an increase in aortic blood flow (11.7 +/- 3.6%, p less than 0.01) whilst the ND had no significant effect on this parameter (+ 6.07 +/- 5.7%). As a result, there was a much greater decrease of peripheral resistances after administration of SYD (-22.8 +/- 3.1%) than with the ND (-12.7 +/- 4.2%). This difference was also observed when the input impedence of the vascular bed was studied (-31.2 +/- 6.9% after SYD and -12.0 +/- 2.5% after the ND).(ABSTRACT TRUNCATED AT 250 WORDS)
Friggi
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A
INSERM U 278, faculté de pharmacie, Marseille.
Bodard
H
H
Berenger-Bahuet
F P
FP
Rolland
P H
PH
Piquet
P
P
Mercier
C
C
Luccioni
R
R
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003187:Compliance / Q000187:drug effects; D004548:Elasticity / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008838:Microcomputers; D008955:Models, Cardiovascular; D011817:Rabbits; D014463:Ultrasonography / Q000379:methods*; D014666:Vasomotor System / Q000187:drug effects / Q000502:physiology*
Application des techniques ultrasonomicrométriques à l'étude de la vasomotricité.