Hypoxia-induced release of catecholamines

In response to intermittent hypoxia (4 % O2 5 % CO2), incubated cat carotid bodies released catecholamines (Wang and Fitzgerald 2002). The M2 muscarinic receptor agonist, methoctramine, enhanced the hypoxia-induced release of catecholamines during each exposure. 

Wang H-Y Fitzgerald RS. Muscarinic modulation of hypoxia-induced release of catecholamines from the cat carotid body. Brain Res 2002 927 122-137. 

There are only a few studies of the CB aiming to alter the elimination of ROS by the cells. Osanai et al. (52) found that aminotriazole, an inhibitor of catalase that should produce an increase in H2O2 levels and thereby a tendency for GSH and GSH/GSSG to decrease, does not affect the frequency of discharge in the carotid sinus nerve ehcited by hypoxia. We have already commented on recent data fi om our laboratory (40) showing that iV-acetylcysteine increased absolute GSH levels and GSH/GSSG ratio and yet it did not alter the basal normoxic or the hypoxia-induced release of catecholamines from chemoreceptor cells. 

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