ME Zacour and JG Martin
Meakins-Christie Laboratories, Royal Victoria Hospital, McGill University, Montreal, Quebec, Canada.

The highly inbred Fisher rat strain demonstrates both hyperresponsiveness of the airways to bronchoconstrictors and increased amounts of airway smooth muscle when compared with Lewis rats. We postulated that the excess airway smooth muscle in Fisher was attributable to a greater sensitivity to endogenous mitogenic stimuli with signaling mechanisms common to contractile stimuli. To test this possibility we investigated differences in the growth response of cultured airway smooth muscle cells (SMC) from these two strains. The Fisher SMC demonstrated an enhanced growth response to fetal bovine serum (FBS), as measured both by cell counting and [3H]thymidine incorporation. The difference in growth response was attributable to a more rapid transition in Fisher than Lewis SMC from the G0/G1 phase to the S phase of the cell cycle. When SMC growth was stimulated by either serotonin, endothelin 1, insulin, platelet-derived growth factor (PDGF), or combinations of the above factors, significant interstrain growth response differences were found only with either human PDGF (AB) or a combination of porcine PDGF (BB) and insulin. A polyclonal antibody to PDGF was less inhibitory to Fisher than Lewis SMC following stimulation with FBS. Thus, interstrain growth differences may reflect different responses to PDGF present in FBS, or to other factors which exert an influence during the G0 or G1 phase of the cell cycle.

This article has been cited by other articles:

				J. G. Martin and T. Jo Genetic Differences in Airway Smooth Muscle Function Proceedings of the ATS, January 1, 2008; 5(1): 73 - 79. [Abstract] [Full Text] [PDF]

				C. G. McVicker, S.-Y. Leung, V. Kanabar, L. M. Moir, K. Mahn, K. F. Chung, and S. J. Hirst Repeated Allergen Inhalation Induces Cytoskeletal Remodeling in Smooth Muscle from Rat Bronchioles Am. J. Respir. Cell Mol. Biol., June 1, 2007; 36(6): 721 - 727. [Abstract] [Full Text] [PDF]

				S. S. An, B. Fabry, X. Trepat, N. Wang, and J. J. Fredberg Do Biophysical Properties of the Airway Smooth Muscle in Culture Predict Airway Hyperresponsiveness? Am. J. Respir. Cell Mol. Biol., July 1, 2006; 35(1): 55 - 64. [Abstract] [Full Text] [PDF]

				F-X. Blanc, C. Coirault, S. Salmeron, D. Chemla, and Y. Lecarpentier Mechanics and crossbridge kinetics of tracheal smooth muscle in two inbred rat strains Eur. Respir. J., August 1, 2003; 22(2): 227 - 234. [Abstract] [Full Text] [PDF]

				A. Cogo, G. Napolitano, M. C. Michoud, D. R. Barbon, M. Ward, and J. G. Martin Effects of hypoxia on rat airway smooth muscle cell proliferation J Appl Physiol, April 1, 2003; 94(4): 1403 - 1409. [Abstract] [Full Text] [PDF]

				F. C. Tao, S. Shah, A. A. Pradhan, B. Tolloczko, and J. G. Martin Enhanced calcium signaling to bradykinin in airway smooth muscle from hyperresponsive inbred rats Am J Physiol Lung Cell Mol Physiol, January 1, 2003; 284(1): L90 - L99. [Abstract] [Full Text] [PDF]

				M.-C. Michoud, G. Napolitano, K. Maghni, V. Govindaraju, A. Cogo, and J. G. Martin Effects of Extracellular Triphosphate Nucleotides and Nucleosides on Airway Smooth Muscle Cell Proliferation Am. J. Respir. Cell Mol. Biol., December 1, 2002; 27(6): 732 - 738. [Abstract] [Full Text] [PDF]

				F. C. Tao, B. Tolloczko, C. A. Mitchell, W. S. Powell, and J. G. Martin Inositol (1,4,5)Trisphosphate Metabolism and Enhanced Calcium Mobilization in Airway Smooth Muscle of Hyperresponsive Rats Am. J. Respir. Cell Mol. Biol., October 1, 2000; 23(4): 514 - 520. [Abstract] [Full Text]

				M. E. Zacour and J. G. Martin Protein kinase C is involved in enhanced airway smooth muscle cell growth in hyperresponsive rats Am J Physiol Lung Cell Mol Physiol, January 1, 2000; 278(1): L59 - L67. [Abstract] [Full Text] [PDF]

				F. C. TAO, B. TOLLOCZKO, D. H. EIDELMAN, and J. G. MARTIN Enhanced Ca2+ Mobilization in Airway Smooth Muscle Contributes to Airway Hyperresponsiveness in an Inbred Strain of Rat Am. J. Respir. Crit. Care Med., August 1, 1999; 160(2): 446 - 453. [Abstract] [Full Text]