Pannexin 1 Channels Control the Hemodynamic Response to Hypoxia by Regulating O2-Sensitive Extracellular ATP in Blood.

Pannexin 1 Channels Control the Hemodynamic Response to Hypoxia by Regulating O2-Sensitive Extracellular ATP in Blood. Am J Physiol Heart Circ Physiol. 2021 Jan 15;: Authors: Kirby BS, Sparks MA, Lazarowski ER, Lopez Domowicz DA, Zhu H, McMahon TJ Abstract Pannexin1 (Panx1) channels export ATP and may contribute to increased concentration of the vasodilator ATP in plasma during hypoxia in vivo. We hypothesized that Panx1 channels and associated ATP export contributes to hypoxic vasodilation, a mechanism that facilitates the matching of oxygen delivery to tissue metabolic demand. Male and female mice devoid of Panx1 (Panx1-/-) and wild-type controls (WT) were anesthetized, mechanically ventilated, and instrumented with a carotid artery catheter or femoral artery flow transducer for hemodynamic and plasma ATP monitoring during inhalation of 21% (normoxia) or 10% oxygen (hypoxia). ATP export from WT vs. Panx1-/- erythrocytes (RBC) was determined ex vivo via tonometer experimentation across progressive deoxygenation. Mean arterial pressure (MAP) was similar in Panx1-/- (N=6) and WT (N=6) mice in normoxia, but the decrease in MAP in hypoxia seen in WT was attenuated in Panx1-/- mice (-16±9% vs -2±8%; P<0.05). Hindlimb blood flow (HBF) was significantly lower in Panx1-/- (N=6) vs. WT (N=6) basally, and increased in WT but not Panx1-/- mice during hypoxia (8±6% vs -10±13%; P<0.05). Estimation of hindlimb vascular conductance using...
Source: American Journal of Physiology. Heart and Circulatory Physiology - Category: Physiology Authors: Tags: Am J Physiol Heart Circ Physiol Source Type: research