Rabies virus infection prevents the modulation by alpha(2)-adrenoceptors, but not muscarinic receptors, of Ca(2+) channels in NG108-15 cells.
In mouse neuroblastoma x rat glioma hybrid (NG108-15) cells, we examined whether rabies virus infection affects the voltage-dependent Ca(2+) current (I(Ca)) and agonist-induced I(Ca) inhibition. The viral infection had little effect on the current-voltage relationship for peak I(Ca) or on the late I(Ca) that remained at the end of a 200-ms step depolarization. Noradrenaline and carbachol, via alpha(2)-adrenoceptors and muscarinic receptors, respectively, reduced I(Ca) concentration dependently. The maximum effect of noradrenaline was attained at 10 microM with 19.4+/-1.8% inhibition of I(Ca), which was significantly decreased to 9.9+/-1.3% after viral infection. The decrease was not reversed with 100 microM noradrenaline, suggesting that it does not result from a decrease in agonist sensitivity of cells. The maximum effect of carbachol (300 microM; 27.7+/-2.9% inhibition) remained unchanged, despite carbachol sharing intracellular signaling pathways with noradrenaline. These results indicate that in NG108-15 cells, rabies virus infection does not alter the functional expression of voltage-dependent Ca(2+) channels, but it attenuates the alpha(2)-adrenoceptor-mediated I(Ca) inhibition, possibly through some change at the receptor level.
Iwata
M
M
Laboratory of Pharmacology, Department of Veterinary Science, Faculty of Agriculture, Gifu University, 1-1 Yanagido, 501-1193, Gifu, Japan.
Unno
T
T
Minamoto
N
N
Ohashi
H
H
Komori
S
S
D000322:Adrenergic Agonists / Q000494:pharmacology; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000378:metabolism* / Q000502:physiology; D002217:Carbachol / Q000494:pharmacology; D018679:Cholinergic Agonists / Q000494:pharmacology; D004594:Electrophysiology; D006825:Hybridomas; D051379:Mice; D009638:Norepinephrine / Q000494:pharmacology; D011818:Rabies / Q000378:metabolism* / Q000821:virology; D011820:Rabies virus; D051381:Rats; D018341:Receptors, Adrenergic, alpha-2 / Q000378:metabolism*; D011976:Receptors, Muscarinic / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
D000322:Adrenergic Agonists; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D018679:Cholinergic Agonists; D018341:Receptors, Adrenergic, alpha-2; D011976:Receptors, Muscarinic; D002217:Carbachol; D009638:Norepinephrine