CD200 and hypertensive disorder: From the investigation on whether the OXA-induced cardiovascular responses were also mediated by OX2R, the results showed that microinjection of TCS OX2 29 (100pmol) alone into RVLM of AMI rats generated no obvious influence on cardiovascular response, but partially blocked hypertension (114.5±5.6 vs.140±4.7 mmHg; P<0.01) and tachycardia (470±8 vs.530±27 bpm; P<0.05), as well as the left ventricle response (+LVdp/dtmax: 3364±131 vs. 4446±467 mmHg/s; −LVdp/dtmax: −3074±129 vs. −4428±602 mmHg/s; P<0.05), which were all evoked by OXA alone (Fig. 4A–E).