Lobar bronchial blood flow has been reported to increase and decrease acutely after pulmonary arterial obstruction (PAO). Because bronchial blood flow (Q̇br) to the trachea and bronchi is influenced by inspired air temperature, we investigated whether temperature differences could explain these disparate results. In 10 open-chested dogs the left lower lobe (LLL) was isolated and perfused in situ with autologous blood at a controlled temperature with an independent vascular circuit. The abdomen and the chest of the dog were enclosed in a Plexiglas box in which air was fully humidified and temperature could be regulated. Q̇br, determined by the reference flow technique using 16 μm microspheres, was measured before and 30 min after onset of PAO with the air in the box being either at 27 or 39°C and with warmed LLL blood (37°C) in the latter condition. Anastomotic bronchial blood flow [Q̇br(s-p), determined as overflow from the closed LLL vascular circuit and measured in ml·min-1·100 g dry lung wt-1·100 Torr mean systemic pressure-1] was measured continuously at both temperatures. Both before and after PAO, Q̇br and Q̇br(s-p) were closely correlated: Q̇br (ml/min) = 1.12 + 0.978 Q̇br(s-p); R = 0.912. This was true regardless of the presence or the absence of pulmonary flows, showing that the distribution of bronchial blood flow between the anastomotic and the nonanastomotic portion does not change acutely during PAO. When the air in the box was 27°C, Q̇br(s-p) was 19.5 ± 5.2 (SE) and increased to 38.6 ± 8.1 with PAO (P <0.007). When more physiological conditions were achieved by increasing the temperature of air in the box (fully humidified) and by warming the blood of the LLL vascular circuit, Q̇br(s-p) was 80.2 ± 16.2 (P <0.002, compared with pre-PAO value at 27°C) and decreased to 46.0 ± 11.1 (P <0.001) with PAO. Bronchial blood flow and the effect of PAO on it are temperature dependent. At body temperature PAO reduces Q̇br and Q̇br(s-p) in the short term.
|Number of pages||5|
|Journal||Journal of Applied Physiology|
|Publication status||Published - 1987|
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation