Loading...
Please wait, while we are loading the content...
Similar Documents
Parathyroid Ca(2+)-conducting currents are modulated by muscarinic receptor agonists and antagonists.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Chang, Wenhan Chen, T. H. Pratt, Stacy A. Yen, Benedict Shoback, Dolores Marie |
| Copyright Year | 1997 |
| Abstract | Parathyroid cells express Ca(2+)-conducting cation currents, which are activated by raising the extracellular Ca2+ concentration ([Ca2+]o) and blocked by dihydropyridines. We found that acetylcholine (ACh) inhibited these currents in a reversible, dose-dependent manner (50% inhibitory concentration approximately equal to 10(-8) M). The inhibitory effects could be mimicked by the agonist (+)-muscarine. The effects of ACh were blunted by the antagonist atropine and reversed by removing ATP from the pipette solution (+)-Muscarine enhanced the adenosine 3',5'-cyclic monophosphate (cAMP) production by 30% but had no effect on inositol phosphate accumulation in parathyroid cells. Oligonucleotide primers, based on sequences of known muscarinic receptors (M1-M5), were used in reverse transcriptase-polymerase chain reaction (RT-PCR) to amplify receptor cDNA from parathyroid poly (A)+ RNA. RT-PCR products displayed > 90% nucleotide sequence identity to human M2- and M4-receptor cDNAs. Expression of M2-receptor protein was further confirmed by immunoblotting and immunocytochemistry. Thus parathyroid cells express muscarinic receptors of M2 and possibly M4 subtypes. These receptors may couple to dihydropyridine-sensitive, cation-selective currents through the activation of adenylate cyclase and ATP-dependent pathways in these cells. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://ajpendo.physiology.org/content/ajpendo/273/5/E880.full.pdf |
| PubMed reference number | 9374672v1 |
| Volume Number | 273 |
| Issue Number | 5 |
| Part | 1 |
| Journal | The American journal of physiology |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | 8-chloro-cyclic adenosine monophosphate Adenosine Diphosphate Adenosine Triphosphate Adenylate Cyclase Atropine Base Sequence Cations DNA, Complementary Dihydropyridines Immunoblotting Immunocytochemistry Inositol Phosphates Muscarinic Acetylcholine Receptor Nucleotides Pipette (physical object) Poly A RNA RNA-Directed DNA Polymerase Reverse Transcriptase Polymerase Chain Reaction Subtype (attribute) |
| Content Type | Text |
| Resource Type | Article |
