Abstract
1. When lung parenchymal strips are challenged with different smooth muscle agonists, the tensile and viscoelastic properties change. It is not clear, however, which of the different anatomical elements present in the parenchymal strip, i.e., small vessel, small airway or alveolar wall, contribute to the response. 2. Parenchymal lung strips from Sprague Dawley rats were suspended in an organ bath filled with Krebs solution (37 degrees C, pH = 7.4) bubbled with 95%O2/5%CO2. Resting tension (T) was set at 1.1 g and sinusoidal oscillations of 2.5% resting length (L0) at a frequency of 1 Hz were applied. Following 1 h of stress adaptation, measurements of length (L) and T were recorded under baseline conditions and after challenge with a variety of pharmacological agents, i.e., acetylcholine (ACh), noradrenaline (NA) and angiotensin II (AII). Elastance (E) and resistance (R) were calculated by fitting changes in T, L and delta L/ delta t to the equation of motion. Hysteresivity (eta, the ratio of the energy dissipated to that conserved) was obtained from the equation eta = (R/E)2 pi f. 3. In order to determine whether small airways or small vessels accounted for the responses to the different pharmacologic agents, further studies were carried out in lung explants. Excised lungs from Sprague Dawley rats were inflated with agarose. Transverse slices of lung (0.5-1.0 mm thick) were cultured overnight. By use of an inverted microscope and video camera, airway and vascular lumen area were measured with an image analysis system. 4. NA, ACh and AII constricted the parenchymal strips. Airways constricted after all agonists, vessels constricted only after All. Atropine (Atr) pre-incubation decreased the explanted airway and vessel response to AII, but no difference was found in the parenchymal strip response. 5. Preincubation with the arginine analogue N omega-nitro-L-arginine (L-NOARG) did not modify the response to ACh but mildly increased the oscillatory response to NA after co-preincubation with propranolol (Prop). 6. These results suggest that during ACh and NA challenge, small vessels do not contribute substantially to the parenchymal strip response. The discrepancy between results in airways, vessels and strips when Atr was administered prior to AII implicates a direct contractile response in the parenchymal strip.
Full text
PDF






Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bertram J. F., Goldie R. G., Papadimitriou J. M., Paterson J. W. Correlations between pharmacological responses and structure of human lung parenchyma strips. Br J Pharmacol. 1983 Sep;80(1):107–114. doi: 10.1111/j.1476-5381.1983.tb11055.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Black J., Turner A., Shaw J. alpha-adrenoceptors in human peripheral lung. Eur J Pharmacol. 1981 Jun 10;72(1):83–86. doi: 10.1016/0014-2999(81)90300-9. [DOI] [PubMed] [Google Scholar]
- Clayton D. E., Busse W. W., Buckner C. K. Contribution of vascular smooth muscle to contractile responses of guinea-pig isolated lung parenchymal strips. Eur J Pharmacol. 1981 Mar 26;70(3):311–320. doi: 10.1016/0014-2999(81)90165-5. [DOI] [PubMed] [Google Scholar]
- Dandurand R. J., Wang C. G., Phillips N. C., Eidelman D. H. Responsiveness of individual airways to methacholine in adult rat lung explants. J Appl Physiol (1985) 1993 Jul;75(1):364–372. doi: 10.1152/jappl.1993.75.1.364. [DOI] [PubMed] [Google Scholar]
- Drazen J. M., Schneider M. W. Comparative responses of tracheal spirals and parenchymal strips to histamine and carbachol in vitro. J Clin Invest. 1978 Jun;61(6):1441–1447. doi: 10.1172/JCI109063. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fredberg J. J., Bunk D., Ingenito E., Shore S. A. Tissue resistance and the contractile state of lung parenchyma. J Appl Physiol (1985) 1993 Mar;74(3):1387–1397. doi: 10.1152/jappl.1993.74.3.1387. [DOI] [PubMed] [Google Scholar]
- Fredberg J. J., Stamenovic D. On the imperfect elasticity of lung tissue. J Appl Physiol (1985) 1989 Dec;67(6):2408–2419. doi: 10.1152/jappl.1989.67.6.2408. [DOI] [PubMed] [Google Scholar]
- Gasc J. M., Shanmugam S., Sibony M., Corvol P. Tissue-specific expression of type 1 angiotensin II receptor subtypes. An in situ hybridization study. Hypertension. 1994 Nov;24(5):531–537. doi: 10.1161/01.hyp.24.5.531. [DOI] [PubMed] [Google Scholar]
- Gunst S. J., Stropp J. Q., Service J. Mechanical modulation of pressure-volume characteristics of contracted canine airways in vitro. J Appl Physiol (1985) 1990 May;68(5):2223–2229. doi: 10.1152/jappl.1990.68.5.2223. [DOI] [PubMed] [Google Scholar]
- Ingenito E. P., Davison B., Fredberg J. J. Tissue resistance in the guinea pig at baseline and during methacholine constriction. J Appl Physiol (1985) 1993 Dec;75(6):2541–2548. doi: 10.1152/jappl.1993.75.6.2541. [DOI] [PubMed] [Google Scholar]
- Kapanci Y., Assimacopoulos A., Irle C., Zwahlen A., Gabbiani G. "Contractile interstitial cells" in pulmonary alveolar septa: a possible regulator of ventilation-perfusion ratio? Ultrastructural, immunofluorescence, and in vitro studies. J Cell Biol. 1974 Feb;60(2):375–392. doi: 10.1083/jcb.60.2.375. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Keeney S. E., Oelberg D. G. Alpha 1-adrenergic and muscarinic receptors in adult and neonatal rat type II pneumocytes. Lung. 1993;171(6):355–366. doi: 10.1007/BF00165701. [DOI] [PubMed] [Google Scholar]
- Lauzon A. M., Bates J. H. Estimation of time-varying respiratory mechanical parameters by recursive least squares. J Appl Physiol (1985) 1991 Sep;71(3):1159–1165. doi: 10.1152/jappl.1991.71.3.1159. [DOI] [PubMed] [Google Scholar]
- Leach R. M., Twort C. H., Cameron I. R., Ward J. P. A comparison of the pharmacological and mechanical properties in vitro of large and small pulmonary arteries of the rat. Clin Sci (Lond) 1992 Jan;82(1):55–62. doi: 10.1042/cs0820055. [DOI] [PubMed] [Google Scholar]
- Lipworth B. J., Dagg K. D. Vasoconstrictor effects of angiotensin II on the pulmonary vascular bed. Chest. 1994 May;105(5):1360–1364. doi: 10.1378/chest.105.5.1360. [DOI] [PubMed] [Google Scholar]
- Ludwig M. S., Dallaire M. J. Structural composition of lung parenchymal strip and mechanical behavior during sinusoidal oscillation. J Appl Physiol (1985) 1994 Oct;77(4):2029–2035. doi: 10.1152/jappl.1994.77.4.2029. [DOI] [PubMed] [Google Scholar]
- Ludwig M. S., Dreshaj I., Solway J., Munoz A., Ingram R. H., Jr Partitioning of pulmonary resistance during constriction in the dog: effects of volume history. J Appl Physiol (1985) 1987 Feb;62(2):807–815. doi: 10.1152/jappl.1987.62.2.807. [DOI] [PubMed] [Google Scholar]
- Lulich K. M., Mitchell H. W., Sparrow M. P. The cat lung strip as an in vitro preparation of peripheral airways: a comparison of beta-adrenoceptor agonists, autacoids and anaphylactic challenge on the lung strip and trachea. Br J Pharmacol. 1976 Sep;58(1):71–79. doi: 10.1111/j.1476-5381.1976.tb07694.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mak J. C., Baraniuk J. N., Barnes P. J. Localization of muscarinic receptor subtype mRNAs in human lung. Am J Respir Cell Mol Biol. 1992 Sep;7(3):344–348. doi: 10.1165/ajrcmb/7.3.344. [DOI] [PubMed] [Google Scholar]
- Mizrahi J., Couture R., Caranikas S., Regoli D. Pharmacological effects of peptides on tracheal smooth muscle. Pharmacology. 1982;25(1):39–50. doi: 10.1159/000137722. [DOI] [PubMed] [Google Scholar]
- Nagase T., Dallaire M. J., Ludwig M. S. Airway and tissue responses during hyperpnea-induced constriction in guinea pigs. Am J Respir Crit Care Med. 1994 May;149(5):1342–1347. doi: 10.1164/ajrccm.149.5.8173776. [DOI] [PubMed] [Google Scholar]
- Nagase T., Moretto A., Dallaire M. J., Eidelman D. H., Martin J. G., Ludwig M. S. Airway and tissue responses to antigen challenge in sensitized brown Norway rats. Am J Respir Crit Care Med. 1994 Jul;150(1):218–226. doi: 10.1164/ajrccm.150.1.8025752. [DOI] [PubMed] [Google Scholar]
- Roffel A. F., Elzinga C. R., Zaagsma J. Cholinergic contraction of the guinea pig lung strip is mediated by muscarinic M2-like receptors. Eur J Pharmacol. 1993 Dec 7;250(2):267–279. doi: 10.1016/0014-2999(93)90391-t. [DOI] [PubMed] [Google Scholar]
- Salerno F. G., Dallaire M., Ludwig M. S. Does the anatomic makeup of parenchymal lung strips affect oscillatory mechanics during induced constriction? J Appl Physiol (1985) 1995 Jul;79(1):66–72. doi: 10.1152/jappl.1995.79.1.66. [DOI] [PubMed] [Google Scholar]
- Sardella G. L., Ou L. C. Chronically instrumented rat model for hemodynamic studies of both pulmonary and systemic circulations. J Appl Physiol (1985) 1993 Feb;74(2):849–852. doi: 10.1152/jappl.1993.74.2.849. [DOI] [PubMed] [Google Scholar]
- Sata M., Takahashi K., Sato S., Tomoike H. Structural and functional characteristics of peripheral pulmonary parenchyma in golden hamsters. J Appl Physiol (1985) 1995 Jan;78(1):239–246. doi: 10.1152/jappl.1995.78.1.239. [DOI] [PubMed] [Google Scholar]
- Tepper R. S., Shen X., Bakan E., Gunst S. J. Maximal airway response in mature and immature rabbits during tidal ventilation. J Appl Physiol (1985) 1995 Oct;79(4):1190–1198. doi: 10.1152/jappl.1995.79.4.1190. [DOI] [PubMed] [Google Scholar]
- Tepper R., Sato J., Suki B., Martin J. G., Bates J. H. Low-frequency pulmonary impedance in rabbits and its response to inhaled methacholine. J Appl Physiol (1985) 1992 Jul;73(1):290–295. doi: 10.1152/jappl.1992.73.1.290. [DOI] [PubMed] [Google Scholar]
- Yamawaki I., Tamaoki J., Yamauchi F., Konno K. Angiotensin II potentiates neurally mediated contraction of rabbit airway smooth muscle. Respir Physiol. 1992 Aug;89(2):239–247. doi: 10.1016/0034-5687(92)90053-y. [DOI] [PubMed] [Google Scholar]
