Obstructive Apnea Causes Microvascular Perfusion Mal-Distribution in the Lungs of Rats.

Obstructive Apnea Causes Microvascular Perfusion Mal-Distribution in the Lungs of Rats. Am J Physiol Regul Integr Comp Physiol. 2018 Nov 07;: Authors: Conhaim RL, Watson KE, Teodorescu M Abstract Obstructive sleep apnea (OSA) is associated with significant cardiovascular consequences, including pulmonary hypertension. Yet, little is known about its effects on pulmonary microvascular perfusion. To investigate this, we clamped the tracheal cannulas of anesthetized, spontaneously breathing rats to simulate obstructive apnea. The clamp remained in place for 10 breaths before it was released to allow the animals to again breathe spontaneously. We repeated this every 20 seconds until the rat experienced a total of 5 apneic episodes of 10 breaths each. We then infused into a femoral vein 108 4 µm diameter fluorescent latex particles which became trapped within the pulmonary microcirculation. We removed the lungs, allowed them to air-dry, and quantified the particle distributions in sections of the lungs using Dispersion Index analysis, which is a method we developed previously. The log of the Dispersion Index (logDI) is a measure of perfusion mal-distribution. Greater values correspond to greater maldistribution. Apneic lungs had average logDI values of 1.28±0.24. Rats not subjected to apnea had average logDI values of 0.85±0.08 (p≤0.05). Rats that received latex particles 10 minutes or 24 hours after apnea had average logDI values of ...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - Category: Physiology Authors: Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research