Effect of Nao-re-qing oral liquid on cAMP content in hypothalamus and CSF,and AVP content in ventral septal area of endotoxin-induced febrile rabbits

AIM: To explore the mechanism of Nao-re-qing oral liquid (NRQ) decreasing endotoxin (ET)-induced fever in rabbits. METHODS: (1) The ET-induced fever model was established in rabbits. Febrile response of rabbits was observed. (2) The arginine vasopressin (AVP) content in the ventral septal area (VSA), and cAMP content in hypothalarmus (HP) and CSF were determined by radioimmunoassay.RESULTS: (1) In ET group, the maximal increment in body temperature (ΔT) [(1.80±0.16) ℃], 6 h thermal respone index (TRI₆)(11.31±0.20), the cAMP content in the HP [(1.35±0.21)nmol/g], the cAMP content in CSF [(66.69±1.82) nmol/L] and AVP content in the VSA [(30.80±9.59)ng/g ] were significantly higher than those in NRQ+ET group[ΔT(0.82±0.08) ℃, TRI₆(5.73±0.09), HP: cAMP(0.70±0.50)nmol/g, CSF: cAMP(56.86±1.34), AVP:(11.91±3.47)ng/g]( P<0.01). (2) The AVP content in VSA, and cAMP content in HP and CSF were separately paralleled with the fluctuation of body temperature (AVP: r=0.972, P<0.01; HP: cAMP r=0.899, P<0.05; CSF: cAMP r=0.991, P<0.01). CONCLUSION: The antipyretic action of NRQ may be due to inhibiting the increase in cAMP in HP and meanwhile promoting the release of AVP in VSA.