Abstract
The effects of extracellular ATP on the L-type Ca2+ current (I(Ca), action potential, and resting and intracellular Ca2+ levels were examined in enzymatically isolated myocytes from the right ventricles of ferrets. Extracellular ATP decreased the peak amplitude of I(Ca) in a time- and concentration-dependent manner. The concentration-response relationship for ATP inhibition of I(Ca) was well described by a conventional Michaelis- Menten relationship with a half maximal inhibitory concentration of 1 μM and a maximal effect of 50%. Extracellular ATP did not change the resting myoplasmic Ca2+ levels; however, it did decrease the Ca2+ transient. The effects of extracellular ATP were mediated independently of adenosine A1 receptors and a pertussis-toxin sensitive G protein. Pharmacological characterization of receptor subtype using ATP analogs was consistent with ATP binding to a P(2Y) type receptor.
Original language | English (US) |
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Pages (from-to) | 11-18 |
Number of pages | 8 |
Journal | Advances in Experimental Medicine and Biology |
Volume | 346 |
State | Published - 1993 |
Externally published | Yes |
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)