Submandibular Gland Acinar Cells Express Multiple α1-Adrenoceptor Subtypes
| Autor: | Margaret A. Scofield, Kelly A. O'Connell, Peter W. Abel, Charles S. Bockman, Wanyun Zeng, Michael R. Bruchas, Frank J. Dowd |
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| Rok vydání: | 2004 |
| Předmět: |
Male
medicine.medical_specialty Submandibular Gland Tritium Clonidine Rats Sprague-Dawley Radioligand Assay stomatognathic system Receptors Adrenergic alpha-2 Receptors Adrenergic alpha-1 Internal medicine Acinar cell medicine Prazosin Animals Secretion RNA Messenger Binding site Receptor Adrenergic alpha-Antagonists Cells Cultured Pharmacology Chemistry Cell Membrane Submandibular gland α1 adrenoceptor Rats Endocrinology medicine.anatomical_structure α1b adrenoceptor Molecular Medicine medicine.drug |
| Zdroj: | Journal of Pharmacology and Experimental Therapeutics. 311:364-372 |
| ISSN: | 1521-0103 0022-3565 |
| Popis: | We evaluated an acinar cell line (SMG-C10) cloned from rat submandibular glands as a possible model for alpha(1)-adrenoceptor regulation of submandibular function. alpha(1)-Adrenoceptors are subdivided into three subtypes called alpha(1A), alpha(1B), and alpha(1D), which can be distinguished from one another by their differential affinity values for subtype-selective alpha(1)-adrenoceptor antagonists. Thus, alpha(1)-adrenoceptor subtypes in SMG-C10 cells were characterized with reverse transcription-polymerase chain reaction (RT-PCR) and [(3)H]prazosin binding in side-by-side experiments with native submandibular glands. RT-PCR identified mRNAs for alpha(1A)-, alpha(1B)-, and alpha(1D)-adrenoceptors in SMG-C10 cells and submandibular glands. The inhibition of [(3)H]prazosin binding by 5-methylurapidil (alpha(1A)-selective) was biphasic and fit best to a two-site binding model with 40 +/- 8% high (K(iH))- and 60 +/- 10% low (K(iL))-affinity binding sites in SMG-C10 cells, and 76% high- and 24% low-affinity binding sites in submandibular glands. Respective K(iH) and K(iL) values for 5-methylurapidil were 1.9 +/- 0.4 and 100 +/- 30 nM in SMG-C10 cells and 3.2 +/- 0.8 and 170 +/- 20 nM in submandibular glands. BMY-7378 [8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro[4.5]decane-7,9-dione dihydrochloride (alpha(1D)-selective)] bound with low affinity in SMG-C10 cells and submandibular glands with K(i) values of 81 +/- 20 and 110 +/- 20 nM, respectively. Chloroethylclondine, an irreversible alkylating agent selective for alpha(1B) adrenoceptors, reduced the density of [(3)H]prazosin binding sites by 42 and 26% in SMG-C10 and submandibular membranes, respectively. Thus, SMG-C10 cells and submandibular glands are similar in expressing receptor protein for alpha(1A)- and alpha(1B)-adrenoceptor subtypes, establishing SMG-C10 cells as a potential model for alpha(1)-adrenoceptor-mediated secretion. |
| Databáze: | OpenAIRE |
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