Hypoxic phrenic responses are unaltered by intrapleural PKCθ siRNA. Phrenic nerve amplitude (% baseline) during short-term hypoxia after pretreatment with intrapleural injections of nontargeting siRNA (NTsiRNA, n = 7), PKCθ siRNA (siPKCθ, n = 7), or PKCζ siRNA (siPKCζ, n = 5). Time control rats (no AIH, n = 10) are shown for comparison. *p < 0.05, significant difference versus time controls. #p < 0.05, significant difference versus intrapleural siPKCθ+AIH. &p < 0.05, significant difference versus intrapleural NTsiRNA+AIH.