Macro‐ and microcirculatory effects of tetramethylpyrazine and extract of Charthamus tinctorius L. in rabbit mesentery

Abstract

Effects of tetramethylpyrazine (TMP) and that of extracts of Charthamus tinctorius L. (CTL) on the macro‐ and microcirculation in rabbit mesentery were studied. The intestinal arterial blood flow (Qa) was measured using an electromagnetic flowmeter, together with the arterial blood pressure (Pa). The inner diameter and red cell velocity in single arteriole in the mesentery were measured by a video‐image technique and a dual‐slit photometric method, respectively. Using the measured diameter and red cell velocity, the arteriolar blood flow (Qm) was calculated. Both the Qa and Qm decreased when Pa was decreased after the intravenous administration of TMP, CTL, Nicardipine, Phentolamine and acetylcholine (Ach). Changes in Qa and Qm with changes in Pa were analyzed, and it was found that (i) both the Pa–Qa and Pa–Qm curves, during the administration of TMP or CTL, show different patterns from those during the administration of Nicardipine or Phentolamine; (ii) the Pa–Qa and Pa–Qm curves after the administration of TMP or CTL show similar patterns with those after the administration of Ach.