caa a22 4500 469078472 CHVBK 20180323132942.0 cr unu---uuuuu 170328e19921101xx s 000 0 eng 10.1007/BF00169015 doi (NATIONALLICENCE)springer-10.1007/BF00169015 Effects of low temperature and pharmacological interventions on the responses of the isolated guinea-pig trachea [Elektronische Daten] [J. Cortijo, M. Gonzalez, J.L. Ortiz, E. Morcillo] Summary: Cooling the guinea-pig isolated trachea from 37°C to 20°C virtually abolished the response to CaCl2 (in K+-depolarized tissues) and depressed that to histamine (about 75% reduction), KCl and 5-hydroxytryptamine (around 50% inhibition) while the response to acetylcholine remained unaffected. A further cooling to 10°C was necessary to inhibit acetylcholine-induced contractions. Hyporesponsiveness to spasmogens by cooling was not associated with subsensitivity (increased EC50) except for 5-hydroxytryptamine. Contractile responses to KCl (50 mmol/l), histamine (1 mmol/l) and 5-hydroxytryptamine (0.1 mmol/l) in a Ca2+-free EGTA (0.1 mmol/l)-containing solution were inhibited by cooling to 20°C but responses to acetylcholine (1 mmol/l) in the same experimental conditions were not affected. Cooling to 20°C after treatment with an antagonist (ouabain 10 µmol/l, amiloride 0.1 mmol/l or vanadate 0.1 mmol/l) or after incubation in K+-free medium or low Na+ (25 mmol/l) solution produced the same or greater inhibitions of tracheal responses to spasmogens than cooling alone. The guinea-pig trachea treated with phorbol 12,13-diacetate (PDA; 1 µmol/l) and cooled to 20°C responded to spasmogens similarly to a trachea untreated with PDA at 37°C. In contrast, PDA (1 µmol/l) did not counteract the depressed responsiveness to histamine of ouabain (10 µmol/l)- or amiloride (0.1 mmol/l)- treated tracheal strips at 37°C. PDA (1 μmol/l) enhanced tracheal contractions caused by KCl (50 mmol/l) in Ca2+-free medium at 20°C but failed to augment those to histamine in the same conditions. PDA (0.1 or 1 µmol/l) did not change the concentration-response curve for Ca2+ in skinned trachea. In conclusion, low temperature inhibits the responses to spasmogens in the guinea-pig trachea. Probably, reduced temperature interferes with extracellular and intracellular sources of Ca2+ which are differently affected by various spasmogens. Alteration by cooling of the electrogenic Na+ pump, Na+/Ca2+ exchange system, and Ca2+-ATPase may participate in the decrease of tracheal responsiveness to agonists. Reversion by PDA of the inhibitory effect of low temperature suggests a role for protein kinase C in the cooling-induced changes of tracheal responses. Springer-Verlag, 1992 Guinea-pig trachea nationallicence Cooling nationallicence Phorbol 12,13-diacetate nationallicence Airway smooth muscle nationallicence Cortijo J. Department of Farmacologia, Facultat de Medicina, Universitat de Valencia, Av. Blasco Ibañez, 15, E-46010, Valencia, Spain aut Gonzalez M. Department of Farmacologia, Facultat de Medicina, Universitat de Valencia, Av. Blasco Ibañez, 15, E-46010, Valencia, Spain aut Ortiz J.L. Department of Farmacologia, Facultat de Medicina, Universitat de Valencia, Av. Blasco Ibañez, 15, E-46010, Valencia, Spain aut Morcillo E. Department of Farmacologia, Facultat de Medicina, Universitat de Valencia, Av. Blasco Ibañez, 15, E-46010, Valencia, Spain aut Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/5(1992-11-01), 573-580 0028-1298 346:5<573 1992 346 210 https://doi.org/10.1007/BF00169015 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00169015 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cortijo J. Department of Farmacologia, Facultat de Medicina, Universitat de Valencia, Av. Blasco Ibañez, 15, E-46010, Valencia, Spain aut NATIONALLICENCE 700 1- Gonzalez M. Department of Farmacologia, Facultat de Medicina, Universitat de Valencia, Av. Blasco Ibañez, 15, E-46010, Valencia, Spain aut NATIONALLICENCE 700 1- Ortiz J.L. Department of Farmacologia, Facultat de Medicina, Universitat de Valencia, Av. Blasco Ibañez, 15, E-46010, Valencia, Spain aut NATIONALLICENCE 700 1- Morcillo E. Department of Farmacologia, Facultat de Medicina, Universitat de Valencia, Av. Blasco Ibañez, 15, E-46010, Valencia, Spain aut NATIONALLICENCE 773 0- Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/5(1992-11-01), 573-580 0028-1298 346:5<573 1992 346 210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer