Antishock effect of anisodamine involves a novel pathway for activating alpha7 nicotinic acetylcholine receptor.
OBJECTIVE
Vagus nerve stimulation inhibits proinflammatory cytokine production by signaling through the alpha7 nicotinic acetylcholine receptor (alpha7nAChR). Anisodamine, a muscarinic acetylcholine receptor antagonist, has been used clinically in China for treatment of various shocks, but the mechanism was poorly understood. Here, we tested the hypothesis whether anisodamine attained its antishock effect through activation of alpha7nAChR.


METHODS
: Randomized and controlled in vitro and in vivo study.


METHODS
Research laboratory and animal facility rooms.


METHODS
Sprague-Dawley rats, Kunming mice, alpha7nAChR-deficient mice, and RAW264.7 cells.


METHODS
Sprague-Dawley rats were injected with lipopolysaccharide (LPS) (15 mg/kg, intravenous) to induce septic shock. Methyllycaconitine, a selective alpha7nAChR antagonist, was administered (10 mg/kg, intraperitoneal) 10 minutes before anisodamine (10 mg/kg, intravenous). Mean arterial pressure was monitored and cytokines were analyzed 2 hours after the onset of LPS. In vagotomized mice and alpha7nAChR-deficient mice, the antishock effect of anisodamine was appraised, respectively. RAW264.7 cells were stained by fluorescein isothiocyanate- labeled-alpha-bungarotoxin and the fluorescence intensity was observed. Mice peritoneal macrophages were pretreated and stimulated with LPS, and tumor necrosis factor (TNF)-alpha in the supernatant was measured by enzyme-linked immunosorbent assay.


RESULTS
Methyllycaconitine significantly antagonized the beneficial effect of anisodamine on mean arterial pressure and TNF-alpha, interleukin-1beta expression in response to LPS. The antishock effects of anisodamine were markedly attenuated in vagotomized mice and alpha7nAChR-deficient mice. In vitro, anisodamine significantly augmented the effect of acetylcholine on fluorescence intensity stained with fluorescein isothiocyanate-labeled-alpha-bungarotoxin and TNF-alpha production stimulated with LPS.


CONCLUSIONS
These findings demonstrate that the antishock effect of anisodamine is intimately linked to alpha7nAChR-dependent anti-inflammatory pathway.
Liu
Chong
C
Department of Pharmacology, Second Military Medical University, Shanghai, China.
Shen
Fu-Ming
FM
Le
Ying-Ying
YY
Kong
Yan
Y
Liu
Xia
X
Cai
Guo-Jun
GJ
Chen
Alex F
AF
Su
Ding-Feng
DF
D000157:Aconitine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002681:China; D017931:DNA Primers; D053583:Interleukin-1beta / Q000378:metabolism; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D018722:Nicotinic Agonists / Q000494:pharmacology* / Q000627:therapeutic use; D018733:Nicotinic Antagonists / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D051381:Rats; D017207:Rats, Sprague-Dawley; D011978:Receptors, Nicotinic / Q000187:drug effects*; D012772:Shock, Septic / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D012991:Solanaceous Alkaloids / Q000494:pharmacology* / Q000627:therapeutic use; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000378:metabolism; D014628:Vagotomy; D064569:alpha7 Nicotinic Acetylcholine Receptor
C579166:Chrna7 protein, mouse; C579165:Chrna7 protein, rat; D017931:DNA Primers; D053583:Interleukin-1beta; D018722:Nicotinic Agonists; D018733:Nicotinic Antagonists; D011978:Receptors, Nicotinic; D012991:Solanaceous Alkaloids; D014409:Tumor Necrosis Factor-alpha; D064569:alpha7 Nicotinic Acetylcholine Receptor; C003922:anisodamine; C054634:methyllycaconitine; D000157:Aconitine