Immune sensitization augments epithelium-dependent spontaneous tone in guinea pig trachealis
| Autor: | Julian Solway, K. Uzendoski, Alan R. Leff, K. Arbetter, I. M. Ndukwu, Richard W. Mitchell |
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| Rok vydání: | 1994 |
| Předmět: |
Atropine
Male Pulmonary and Respiratory Medicine medicine.medical_specialty Ovalbumin Physiology Guinea Pigs Indomethacin Tetrodotoxin In Vitro Techniques Epithelium Guinea pig Physiology (medical) Internal medicine Muscarinic acetylcholine receptor medicine Animals Sensitization Aerosols Dose-Response Relationship Drug biology business.industry Isoproterenol Muscle Smooth Cell Biology Propranolol Acetylcholine Electric Stimulation Trachea Dose–response relationship medicine.anatomical_structure Endocrinology Muscle Tonus biology.protein Trachealis muscle Immunization medicine.symptom business medicine.drug Muscle contraction |
| Zdroj: | American Journal of Physiology-Lung Cellular and Molecular Physiology. 266:L485-L492 |
| ISSN: | 1522-1504 1040-0605 |
| DOI: | 10.1152/ajplung.1994.266.5.l485 |
| Popis: | We examined epithelial modulation of tracheal smooth muscle (TSM) responsiveness in vitro from guinea pigs receiving active immune sensitization in vivo. Initially, guinea pigs were either ovalbumin sensitized (by aerosol) or sham sensitized with normal saline; TSM responsiveness was assessed isometrically as active tension (AT) after equilibration by electrical field stimulation in vitro. For epithelium-intact (Epi+) tissues, sensitization caused an increase in baseline active spontaneous tone (1.89 +/- 0.20 g AT) vs. sham-sensitized tissues (1.18 +/- 0.28 g AT; P = 0.02). Spontaneous tone in sensitized TSM in which the epithelium was removed (Epi-) (1.01 +/- 0.14 g AT) was substantially less than from Epi+ tissues (P = 0.01) and did not differ from sham-sensitized epithelium-denuded tissues (0.82 +/- 0.24 g AT; P > 0.05). Indomethacin caused a reduction in spontaneous tone to comparable magnitude for all treatment paradigms. Immune sensitization caused physiological reduction in the ability to relax in response to isoproterenol; the concentration of isoproterenol eliciting 50% relaxation of spontaneous tone was 7.10 +/- 0.13 (-log M) for TSM from sensitized guinea pigs compared with 8.20 +/- 0.27 (-log M) for sham-sensitized tissues (P = 0.006). However, after precontraction with exogenous acetylcholine, relaxation caused by isoproterenol was not affected by either indomethacin or epithelial removal. Muscarinic responsiveness to acetylcholine was augmented by immune sensitization; however, the increase in response to acetylcholine was attenuated by epithelium removal or cyclooxygenase blockade.(ABSTRACT TRUNCATED AT 250 WORDS) |
| Databáze: | OpenAIRE |
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