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Differential signalling pathways involved in cholinoceptor‐dependent stimulation of nitric oxide isoforms in dental pulp
Author(s) -
SterinBorda L.,
Furlan C.,
Reina S.,
Orman B.,
Borda E.
Publication year - 2007
Publication title -
international endodontic journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.988
H-Index - 119
eISSN - 1365-2591
pISSN - 0143-2885
DOI - 10.1111/j.1365-2591.2007.01259.x
Subject(s) - endothelial nos , nitric oxide synthase , pilocarpine , stimulation , nitric oxide , protein kinase c , muscarinic acetylcholine receptor , citrulline , chemistry , calmodulin , arginine , phospholipase c , enos , microbiology and biotechnology , signal transduction , pharmacology , biology , biochemistry , receptor , endocrinology , enzyme , amino acid , neuroscience , epilepsy
Aim To investigate the role of muscarinic acetylcholine receptor (mAChR) subtype activity in the regulation of endothelial‐ (e) and neuronal‐ (n) nitric oxide synthase (NOS) expression and activity. Methodology Rat dental pulp tissue was used throughout the study. The e‐nos and n‐nos mRNA levels were specifically measured using reverse transcriptase polymerase chain reaction procedures that involve simultaneous co‐amplification of both target cDNA and a reference template with a single set of primers. NOS activity was measured by the production of [U‐ 14 C]‐citrulline from [U‐ 14 C]‐arginine. Results Stimulation of M 1 /M 2 and M 3 /M 4 mAChRs with pilocarpine caused an increase in e‐nos and n‐nos mRNA levels and NOS activity in the dental pulp. The specific mAChR subtype antagonists, l ‐NMMA, l ‐NIO and N 2 ‐propyl‐ l ‐arginine but not aminoguanidine attenuated all these effects. Inhibitors of phospholipase C (PLC), protein kinase C (PKC) and calcium/calmodulin (CaM) prevented the pilocarpine‐dependent increase in n‐nos and e‐nos mRNA levels and NOS activity. Conclusions Activation of mAChR subtypes stimulated NOS activity by increasing the production of NO through e‐nos and n‐nos gene expression and NOS activity. The mechanism appears to occur secondarily to stimulation of CaM and PKC enzymatic activity.