プロスタサイクリン(PGI₂)による人為的低血圧時のネコの局所脳血流および炭酸ガス反応性に及ぼす影響

Abstract

The effects of Prostacyclin (PGI₂) on regional blood flow (r-CBF) and CO₂ reactivity were studied in experimental hypotension with cats. The 19 cats, weighing 1.6-4.0 kg, were divided in two groups, PGI₂ administration group (n=10) and the control (n=9). Animals were anesthetized with midazolam, fentanyl, pancuronium and nitrous oxide/oxygen by mechanical ventilation. Closed cranial-windows were prepared on the bilateral parietal bone, through which r-CBF was measured by laser Doppler flowmetry, and intracranial pressures were recorded. Under induced hypotension with PGI₂ (30% reduced from the control value), r-CBF was significantly decreased at 88.9%. In steady states of hypo-, normo-, and hypercarbia, the CO₂ reactivity of r-CBF (Δ%r-CBF/ΔPaco₂) was calculated and compared between the control group and PGI₂ group. There were no significant changes in CO₂ reactivity of r-CBF. We concluded that r-CBF was attenuated by PGI₂ administration which had no effects on CO₂ reactivity.