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EFFECT OF Na+ PUMP SUPPRESSION ON REACTIVITY OF RAT TRACHEALIS TO COOLING
Author(s) -
Chen W. Y.
Publication year - 1989
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.1989.tb01574.x
Subject(s) - trachealis muscle , reactivity (psychology) , chemistry , biophysics , sodium pump , medicine , biology , sodium , potassium channel , organic chemistry , charybdotoxin , ouabain , alternative medicine , pathology
SUMMARY 1. This study tests the hypothesis that suppression of Na+ pump would increase the rate of tension development and the magnitude of contraction induced by cooling in airway smooth muscle. 2. Rat tracheal preparations were incubated in ouabain for 8 h and tested hourly for their response. In a representative specimen the rate of tension development increased from the control value of 0.7 mg/s to 5.5 mg/s after 7 h of incubation in ouabain concentration of 4 × 10 −4 mol/L; likewise, the magnitude of contraction increased from the control value of 80 mg to 550 mg. 3. Using ouabain concentrations between 9 × 10 −5 mol/Land6 × 10 −3 mol/L, the rate of tension development and the magnitude of contraction first increased in a dose‐dependent manner up to 8 × 10 −4 mol/L, then declined with higher doses but the responses were still greater than the control values at all concentrations. 4. After 3 h incubation in ouabain at 8 × 10 −4 mol/L, the mean rate of tension development and the mean magnitude of contraction increased to 647% and 578% of the control value, respectively. 5. These results indicate that depression of Na + pump results in hypersensitivity and hyper‐reactivity of the airway smooth muscle to cooling.