[Changes of intracellular calcium regulatory signals in PC12 cells during the activation and desensitization induced by anatoxin-A].
OBJECTIVE
To investigate changes of the intracellular calcium regulative signals during the activation and desensitization of neural nicotinic acetylcholine receptor induced by anatoxin-A (ANTX-A).


METHODS
The intracellular calcium concentration and the calcium-calmodulin dependent protein phosphatase calcineurin(CaN, PP2B) activity were determined by Fluo-3-AM fluorescence method and luminescence substrate method in the process of cell activation and desensitization.


RESULTS
During the activation and desensitization of PC12 cells stimulated by ANTX-A, [Ca2+]i raised obviously than that of the control group(P < 0.05). And it was decreased by L-voltage sensitive calcium channel (VSCC) inhibitor verapamil (VRP). While the intracellular PP2B activity was lower than that of the control group during the activation, and was higher during the desensitization, and displayed dose-response and time-dependent relation (P < 0.05) that was blocked by nicotinic antagonist mecamylamine(MEC).


CONCLUSIONS
During the activation and desensitization of PCI2 cells evoked by AMTX-A, [Ca2+]i, was both increased obviously. PP2B activity was decreased in the activation and improved in the desensitization. It is suggested that [Ca2+]i and PP2B may be involved in the intracellular signal transduction pathway of the activation and desensitization of neural micotinic receptors induced by ANTX-A.
Zhang
Zhihong
Z
School of Public Health, Fudan University, Shanghai 200032, China.
Qu
Weidong
W
Chen
Guoguang
G
Jiang
Songhui
S
D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D020013:Calcium Signaling; D002147:Calmodulin / Q000378:metabolism; D000458:Cyanobacteria; D000087522:Cyanobacteria Toxins; D008387:Marine Toxins / Q000494:pharmacology*; D052998:Microcystins; D009498:Neurotoxins / Q000494:pharmacology; D018722:Nicotinic Agonists / Q000494:pharmacology*; D016716:PC12 Cells; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D051381:Rats; D011978:Receptors, Nicotinic / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014326:Tropanes
D001427:Bacterial Toxins; D015220:Calcium Channels; D002147:Calmodulin; D000087522:Cyanobacteria Toxins; D008387:Marine Toxins; D052998:Microcystins; D009498:Neurotoxins; D018722:Nicotinic Agonists; D011978:Receptors, Nicotinic; D014326:Tropanes; C509783:anatoxin a; D010749:Phosphoprotein Phosphatases; D002118:Calcium