Abstract
The intact human fibroblast has been used in clinical and basic research studies of receptor-mediated control of cell function, however there is little information about the relationship between muscarinic receptor density and the regulation of cyclic AMP (cAMP) accumulation. We have compared the muscarinic receptor characteristics of both lung and skin intact fibroblasts at fetal and adult stages of development using carbachol-mediated inhibition of cAMP accumulation and the binding of [3H]quinuclidinyl benzilate (QNB). Prostaglandin E1 (PGE1) stimulated cAMP accumulation in all four cell lines, while carbachol inhibited cAMP accumulation only in the fetal lung, adult lung, and to a lesser extent, the fetal skin. Adult skin fibroblasts did not display significant evidence of inhibitory muscarinic receptor activity. [3H]QNB binding was saturable for the fetal and adult lung, and the fetal skin, yielding Kd values of approximately 0.5 nM for these cell lines. Bmax values were 360 fmol/mg for fetal skin, 600 fmol/mg for adult lung, and 876 fmol/mg for the fetal lung. Specific binding of [3H]QNB to adult skin fibroblasts was found to be low and variable. Comparisons of the Bmax values and maximal inhibitory capacities showed that the receptor density paralleled receptor activity in all cell lines. The lack of muscarinic receptor activity in the adult skin fibroblast was confirmed in several different adult skin cell lines, indicating that the adult skin fibroblast may not be an appropriate model for muscarinic receptor activity in clinical investigations.
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- Bourne H. R., Kaslow H. R., Brickman A. S., Farfel Z. Fibroblast defect in pseudohypoparathyroidism, type I: reduced activity of receptor-cyclase coupling protein. J Clin Endocrinol Metab. 1981 Sep;53(3):636–640. doi: 10.1210/jcem-53-3-636. [DOI] [PubMed] [Google Scholar]
- Butcher R. W. Decreased cAMP levels in human diploid cells exposed to cholinergic stimuli. J Cyclic Nucleotide Res. 1978 Dec;4(6):411–421. [PubMed] [Google Scholar]
- Clark R. B., Salmon D. M., Honeyman T. W. Phosphatidic acid inhibition of PGE1-stimulated cAMP accumulation in WI-38 fibroblasts: similarities with carbachol inhibition. J Cyclic Nucleotide Res. 1980;6(1):37–49. [PubMed] [Google Scholar]
- Crouch M. F., Morris C. P., Cheah T. B., Rush R. A. Developmental loss of a smooth muscle muscarinic receptor population. Brain Res. 1982 Jan 28;232(1):212–215. doi: 10.1016/0006-8993(82)90628-x. [DOI] [PubMed] [Google Scholar]
- Dumont Y., Larose L., Morisset J., Poirier G. G. Parallel maturation of the pancreatic secretory response to cholinergic stimulation and the muscarinic receptor population. Br J Pharmacol. 1981 Jun;73(2):347–353. doi: 10.1111/j.1476-5381.1981.tb10428.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Edelstein S. B., Castiglione C. M., Breakfield X. O. Monoamine oxidase activity in normal and Lesch-Nyhan fibroblasts. J Neurochem. 1978 Nov;31(5):1247–1254. doi: 10.1111/j.1471-4159.1978.tb06249.x. [DOI] [PubMed] [Google Scholar]
- Green D. A., Clark R. B. Comparison of the muscarinic-cholinergic and lysophosphatidate inhibition of fibroblast adenylate cyclase demonstrating desensitization to the cholinergic stimulus. Life Sci. 1981 Oct 19;29(16):1629–1639. doi: 10.1016/0024-3205(81)90064-3. [DOI] [PubMed] [Google Scholar]
- Israelsson B., Malmquist J., Kjellström T. Cyclic AMP accumulation in human fibroblast cultures: diabetics compared with normals. Experientia. 1983 Dec 15;39(12):1355–1356. doi: 10.1007/BF01990101. [DOI] [PubMed] [Google Scholar]
- Lenox R. H., Ellis J., Van Riper D., Ehrlich Y. H. Alpha 2-adrenergic receptor-mediated regulation of adenylate cyclase in the intact human platelet. Evidence for a receptor reserve. Mol Pharmacol. 1985 Jan;27(1):1–9. [PubMed] [Google Scholar]
- Levine M. A., Eil C., Downs R. W., Jr, Spiegel A. M. Deficient guanine nucleotide regulatory unit activity in cultured fibroblast membranes from patients with pseudohypoparathyroidism type I. a cause of impaired synthesis of 3',5'-cyclic AMP by intact and broken cells. J Clin Invest. 1983 Jul;72(1):316–324. doi: 10.1172/JCI110971. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nadi N. S., Nurnberger J. I., Jr, Gershon E. S. Muscarinic cholinergic receptors on skin fibroblasts in familial affective disorder. N Engl J Med. 1984 Jul 26;311(4):225–230. doi: 10.1056/NEJM198407263110404. [DOI] [PubMed] [Google Scholar]
- Riker D. K., Roth R. H., Breakefield X. O. High-affinity [3H]choline accumulation in cultured human skin fibroblasts. J Neurochem. 1981 Feb;36(2):746–752. doi: 10.1111/j.1471-4159.1981.tb01651.x. [DOI] [PubMed] [Google Scholar]
- Salomon Y. Adenylate cyclase assay. Adv Cyclic Nucleotide Res. 1979;10:35–55. [PubMed] [Google Scholar]
- Schwartz J. P., Breakefield X. O. Altered nerve growth factor in fibroblasts from patients with familial dysautonomia. Proc Natl Acad Sci U S A. 1980 Feb;77(2):1154–1158. doi: 10.1073/pnas.77.2.1154. [DOI] [PMC free article] [PubMed] [Google Scholar]