Lung perfusion is affected by chronic cold exposure

Background/Aim

The Respiratory system can be affected by exposure to cold. It is well known that acute cold exposure induces asthmatic attacks. However, the influence of chronic cold environment exposure on lung perfusion and the pulmonary circulation was not studied in any previous study. Therefore this study was designed to investigates the effects of chronic cold exposure on lung perfusion using radionuclide study.

Methods

New Zealand White rabbits were used in these experiments. The rabbits were kept in the cold room (4 °C) for 7 weeks. Lung perfusion scintigraphy was performed at the end of this period. Each rabbit was injected with 74 MBq (2 mCi) technetium-99m macroaggregated of albumin (^99mTc MAA). Perfusion studies were done using Gamma camera equipped with a low energy, high resolution, parallel hole collimator interfaced with a computer. Static images were obtained 5 min after administration of the radiotracer. Static images were acquired include anterior/posterior (Ant/Post), right anterior oblique/left posterior oblique (RAO/LPO), right lateral/left lateral (RLat/LLat), right posterior oblique/left anterior oblique (RPO/LAO).

Results

Rabbits chronically exposed to cold had lesser lung perfusion than controls using radionuclide perfusion study. The lung counts of chronic cold exposure (4 °C) for 7 weeks on rabbit lung perfusion for 5 min was 64±4%. (n=6, ^???P<0.001).

Conclusions

Our results indicate that chronic cold exposure decreased pulmonary circulation and lung perfusion in normal subjects. Therefore chronic cold exposure might worsen some diseases that are affected by cold such as asthma.