Excitatory effects of ATP on rat dorsomedial hypothalamic neurons.
We investigated P2X purinoceptors in rat dorsomedial hypothalamic (DMH) neurons using nystatin-perforated patch-clamp recordings and fura-2 microfluorometry. Adenosine triphosphate (ATP) concentration-dependently evoked an inward current and increased cytosolic Ca(2+) ([Ca](i)). The rise in [Ca](i) was dependent on external Ca(2+) and Na(+), was blocked by Ca(2+) channel antagonists and had pharmacological properties consistent with P2X2 receptors. These results suggest that P2X receptor-mediated depolarization activates voltage-gated Ca(2+) channels, resulting in an increase in [Ca](i).
Matsumoto
N
N
Cellular and System Physiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
Sorimachi
M
M
Akaike
N
N
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D002104:Cadmium / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D016257:Fura-2 / Q000493:pharmacokinetics; D007033:Hypothalamus, Middle / Q000166:cytology*; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar
D002121:Calcium Channel Blockers; D002104:Cadmium; C022571:adenosine 5'-O-(3-thiotriphosphate); D000255:Adenosine Triphosphate; D002118:Calcium; D016257:Fura-2