[Influence of carbon monoxide on the expression of inducible nitric oxide synthase mRNA in guinea pigs with allergic rhinitis.].
OBJECTIVE
To study the impact of carbon monoxide (CO) on expression levels of inducible nitric oxide synthase (iNOS) mRNA in guinea pigs with allergic rhinitis (AR).


METHODS
Twenty four guinea pigs were divided randomly into four study groups with 6 guinea pigs in each. The guinea pigs in the first group were treated with saline only (Group 1, the healthy controls). The remaing guinea pigs were sensitized by ovalbumin and thus establishing the AR models. After sensitization, the animals in the second group remained untreated (Group 2, AR control group). The third group was treated with Hemin as the induction group, and the fourth group was treated with Zinc protoporphyrin (ZnPP) as the suppression group. The plasma concentration of carboxyhemoglobin (COHb) was measured, which represents the concentration of CO. The expression levels of Heme oxygenase-1 (HO-1) and NOS mRNAs in nasal mucosa were determined by fluorescent quantitative RT-PCR.


RESULTS
AR models were established successfully in all study guinea pigs. The concentrations of COHb (x(-) +/- s) in plasma of the second group (2.27% +/- 1.13%) were significantly (q = 4.10, P < 0.01) higher than those of healthy controls (1.08% +/- 0.24%). The plasma concentration of COHb in the third group (3.17% +/- 0.68%) were also significantly higher (q = 3.12, P < 0.05) than those in the second group. The expression levels of HO-1 and iNOS in nasal mucosa of the second group [(7.80 +/- 1.60) x 10(-3) and (5.81 +/- 0.05) x 10(-3), respectively] were also significantly (q equals 5.52 and 7.21, respectively, P < 0.01) higher than those of controls [(1.96 +/- 0.71) x 10(-3) and (0.97 +/- 0.05) x 10(-3), respectively]. The expression levels of HO-1 and iNOS in the nasal mucosa of the third group [(11.89 +/- 4.78) x 10(-3) and (7.42 +/- 0.70) x 10(-3), respectively] were significantly (q equals 3.86 and 2.22, P < 0.05) higher than those of the second group. The expression levels of HO-1 and iNOS in nasal mucosa of the fourth group [(3.82 +/- 0.98) x 10(-3) and (2.34 +/- 0.04) x 10(-3), respectively] were significantly (q equals 3.76 and 5.18, P < 0.05) lower than those in the second group.


CONCLUSIONS
Endogenous carbon monoxide influenced the expression levels of iNOS in nasal mocusa in guinea pigs with AR.
Yu
Shao-Qing
SQ
Department of Otorhinolaryngology, Chinese People's Liberation Army Jinan General Hospital, Jinan 250031, China.
Zhang
Ru-Xin
RX
Chen
Ying-Jian
YJ
Yan
Zhi-Qiang
ZQ
Wu
Ge-Ping
GP
Wang
Yan-Sheng
YS
Chen
Jian-Qiu
JQ
Zhu
Chun-Sheng
CS
Li
Gen-Hong
GH
D000818:Animals; D002248:Carbon Monoxide / Q000097:blood; D006168:Guinea Pigs; D051547:Heme Oxygenase-1; D052247:Nitric Oxide Synthase Type II; D012333:RNA, Messenger; D065631:Rhinitis, Allergic
D012333:RNA, Messenger; D002248:Carbon Monoxide; D052247:Nitric Oxide Synthase Type II; D051547:Heme Oxygenase-1