Abstract
The effect of lithium was studied on resting tension of guinea-pig spiral tracheal strips and their responses to carbachol and histamine in vitro. Lithium reversibly relaxed tracheal smooth muscle in a dose-dependent manner. In addition, lithium increased the ED50 for carbachol 10 fold and that for histamine by over 100 fold; maximum responses for each agonist were also reduced. Lithium-induced relaxation of tracheal smooth muscle was unaffected by changes in extracellular calcium concentration over the range 0-11 mM, verapamil, ouabain, procaine, propranolol or reduction in extracellular sodium concentration. The ability of lithium to reduce carbachol- and histamine-induced contraction of tracheal smooth muscle was also not altered by propranolol, procaine, ouabain, verapamil or lowered extracellular sodium. We conclude that lithium acts directly on tracheal smooth muscle to relax it by an as yet unknown mechanism. This may or may not be related to the ability of this agent to alter agonist-induced contraction of tracheal smooth muscle.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Coburn R. F., Yamaguchi T. Membrane potential-dependent and-independent tension in the canine tracheal muscle. J Pharmacol Exp Ther. 1977 May;201(2):276–284. [PubMed] [Google Scholar]
- Ebstein R. P., Hermoni M., Belmaker R. H. The effect of lithium on noradrenaline-induced cyclic AMP accumulation in rat brain: inhibition after chronic treatment and absence of supersensitivity. J Pharmacol Exp Ther. 1980 Apr;213(1):161–167. [PubMed] [Google Scholar]
- Fleisch J. H., Calkins P. J. Comparison of drug-induced responses of rabbit trachea and bronchus. J Appl Physiol. 1976 Jul;41(1):62–66. doi: 10.1152/jappl.1976.41.1.62. [DOI] [PubMed] [Google Scholar]
- Freer R. J., Smith A. B. Effect of lithium of responsiveness of rat uterine smooth muscle to angiotensin. Am J Physiol. 1976 Apr;230(4):1132–1137. doi: 10.1152/ajplegacy.1976.230.4.1132. [DOI] [PubMed] [Google Scholar]
- Freer R. J., Smith A. B. Lithium dissociation of calcium- and angiotensin-induced contractions in depolarized rat uterus. Am J Physiol. 1979 Mar;236(3):C171–C176. doi: 10.1152/ajpcell.1979.236.3.C171. [DOI] [PubMed] [Google Scholar]
- Kirkpatrick C. T. Excitation and contraction in bovine tracheal smooth muscle. J Physiol. 1975 Jan;244(2):263–281. doi: 10.1113/jphysiol.1975.sp010796. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Krell R. D. Pharmacologic characterization of isolated canine bronchial smooth muscle. Eur J Pharmacol. 1978 May 15;49(2):151–155. doi: 10.1016/0014-2999(78)90071-7. [DOI] [PubMed] [Google Scholar]
- Lin C. S., Hurwitz L., Jenne J., Avner B. P. Mechanism of isoproterenol-induced desensitization of tracheal smooth muscle. J Pharmacol Exp Ther. 1977 Oct;203(1):12–22. [PubMed] [Google Scholar]
- Nasr S. J., Atkins R. W. Coincidental improvement in asthma during lithium treatment. Am J Psychiatry. 1977 Sep;134(9):1042–1043. doi: 10.1176/ajp.134.9.1042. [DOI] [PubMed] [Google Scholar]
- Patel P. D., Shah D. S., Patel S. R., Gulati O. D. Investigation of the mechanism of decreased sensitivity of the rat seminal vesicle to norepinephrine by lithium. Pharmacology. 1979;18(2):64–71. doi: 10.1159/000137232. [DOI] [PubMed] [Google Scholar]
- Spilker B., Minatoya H. The role of bronchoconstrictors in evaluating smooth muscle relaxant activity. Arch Int Pharmacodyn Ther. 1975 Oct;217(2):201–217. [PubMed] [Google Scholar]
- White K., Bohart R., Whipple K., Boyd J. Lithium effects on normal subjects. Relationships to plasma and RBC lithium levels. Int Pharmacopsychiatry. 1979;14(3):176–183. doi: 10.1159/000468376. [DOI] [PubMed] [Google Scholar]
- Wong S. K., Buckner C. K. Studies on beta-adrenoceptors mediating changes in mechanical events and adenosine 3',5'-monophosphate levels. Guinea-pig trachea. Eur J Pharmacol. 1978 Feb 1;47(3):273–280. doi: 10.1016/0014-2999(78)90234-0. [DOI] [PubMed] [Google Scholar]