PT  - JOURNAL ARTICLE
AU  - Searl, T. J.
AU  - Silinsky, E. M.
TI  - Modulation of Purinergic Neuromuscular Transmission by Phorbol Dibutyrate is Independent of Protein Kinase C in Murine Urinary Bladder
AID  - 10.1124/jpet.112.194704
DP  - 2012 Aug 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 312--317
VI  - 342
IP  - 2
4099  - http://jpet.aspetjournals.org/content/342/2/312.short
4100  - http://jpet.aspetjournals.org/content/342/2/312.full
SO  - J Pharmacol Exp Ther2012 Aug 01; 342
AB  - Parasympathetic control of murine urinary bladder consists of contractile components mediated by both muscarinic and purinergic receptors. Using intracellular recording techniques, the purinergic component of transmission was measured as both evoked excitatory junctional potentials (EJPs) in response to electrical field stimulation and spontaneous events [spontaneous EJPs (sEJPs)]. EJPs, but not sEJPs, were abolished by the application of the Na+ channel blocker tetrodotoxin and the Ca2+ channel blocker Cd2+. Both EJPs and sEJPs were abolished by the application of the P2X1 antagonist 8,8′-[carbonylbis(imino-4,1-phenylenecarbonylimino-4,1-phenylenecarbonylimino)]bis-1,3,5-naphthalenetrisulfonic acid hexasodium salt (NF279). Application of phorbol dibutyrate (PDBu) increased electrically evoked EJP amplitudes with no effect on mean sEJP amplitudes. Similar increases in EJP amplitudes were produced by PDBu in the presence of either the nonselective protein kinase inhibitor staurosporine or the specific protein kinase C (PKC) inhibitor 2-[1-(3-dimethylaminopropyl)indol-3-yl]-3-(indol-3-yl) maleimide (GF109203X). These results suggest that PDBu increases the purinergic component of detrusor transmission through increasing neurogenic ATP release via a PKC-independent mechanism.