Expression of P2X6 receptors in the enteric nervous system of the rat gastrointestinal tract.
Expression of P2X(4) and P2X(6) receptor subunits in the gastrointestinal tract of the rat was studied with double-labeling fluorescence immunohistochemistry. The results showed that P2X(6) receptors were expressed widely in the submucosal and myenteric plexuses. In the myenteric plexus, P2X(6) receptors were expressed mainly in large size neurons which resembled Dogiel type II neurons. These P2X(6) receptor-immunoreactive (ir) neurons also expressed calbindin 28K, calretinin and neuronal nuclei (NeuN), proteins that are markers of intrinsic sensory neurons. In the submucosal plexus, all the calbindin 28K, calretinin and NeuN-ir cells were immunoreactive for P2X(6) receptors. P2X(6) receptors do not form homomultimers, but rather heteromultimers with either P2X(2) or P2X(4) receptors. P2X(4) receptors were not expressed in neurons, but were expressed in macrophages of the rat gastrointestinal tract. These data indicate that P2X(6) receptors are mainly expressed on intrinsic sensory neurons and that ATP, via P2X(6) receptors probably in heteromeric combination with P2X(2) receptors, may be involved in regulating the physiological functions of these neurons.
Yu
Qiang
Q
Department of Neurobiology, Institute of Neuroscience, Neuroscience Research Centre of Changzheng Hospital, Second Military Medical University, Shanghai, People's Republic of China.
Zhao
Zhengqing
Z
Sun
Jihu
J
Guo
Wei
W
Fu
Jiqiang
J
Burnstock
Geoffrey
G
He
Cheng
C
Xiang
Zhenghua
Z
D000818:Animals; D017615:Enteric Nervous System / Q000166:cytology / Q000378:metabolism*; D041981:Gastrointestinal Tract / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D018048:Receptors, Purinergic P2 / Q000096:biosynthesis*; D058476:Receptors, Purinergic P2X2
C546403:P2rx2 protein, rat; D018048:Receptors, Purinergic P2; D058476:Receptors, Purinergic P2X2; C110590:purinoceptor P2X6