It is being increasingly appreciated that nitric oxide (NO) and carbon monoxide (CO) are
synthesized in mammalian cells and that they function as second messengers. The purpose
of this article is to highlight the current information on NO and CO in the carotid body and
discuss their significance in oxygen chemoreception. The NO synthesizing enzyme, nitric
oxide synthase, is localized to nerve fibers and vascular endothelium in the carotid body. In
vitro biochemical assays have shown that acute hypoxia inhibits NO synthase activity in …