In vivo evaluation of peripheral vascular resistance based on Poiseuille’s law

To elucidate that Poiseuille's law can be applied in vivo microcirculation, we tried to analyze the total peripheral vascular resistance (R_t) and single arteriolar resistance (R_a) obtained from in vivo animal experiments. R_t and R_a values were quantified by measurements of systemic blood pressure (BP) , and by direct observation of microcirculation simultaneously. During L-NAME induced vasoconstriction, systemic BP significantly increased from 91 ± 8 mmHg to 114 ± 9 mmHg, while arterial diameter decreased from 137 ± 31 μm to 129 ± 30 μm (n = 14). The R_t and R_a values during vasoconstriction increased in 23.9 ± 10.4 % and 22.0 ± 9.9 %, respectively, which there were no significant differences. These result confirmed the Poiseuille's law is acceptable to apply for in vivo microcirculation.