ISSN: 1300-0292
İndekslendiği Dizinler: SCIENCE CITATION INDEX EXPANDED
CINAHL, Index Copernicus,
Chemical Abstracts (CA),
Excerpta Medica / EMBASE
Dil: Türkçe, İngilizce
İçerik: Orijinal Araştırma, Derleme, Editöre Mektup, Olgu Sunumu, Tıp Eğitimi, Tıbbi Kitap İncelemeleri
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ORIGINAL RESEARCH ARTICLES |
Effects Of Na+ Transport Inhibitors On 5-ht-, Carbachol-,kcl- And Cacl2-induced Contractions In The Calf Coronary Artery
Ayşe Saide Şahİn*, Kısmet Esra AtalIk*, Hasan Basri Ulusoy**, Necdet Doğan***
* Yrd.Doç.Dr., Selçuk Üniversitesi Tıp Fakültesi Farmakoloji AD,** Arş.Gör.Dr., Selçuk Üniversitesi Tıp Fakültesi Farmakoloji AD,
Purpose: In this in vitro study, the effects of ouabain, K+-free solution, low Na+ (25 mM) solution and amiloride on the responses to Serotonin (5-HT, 10-9- 3x10-4 M), carbachol (10-9- 3x10-4 M), KCl (10-4- 10-1 M) and CaCl2 (10-4- 10-2 M, in Ca++-free and 100 mM KCl solution) were studied in isolated calf coronary artery.
Materials and metods: Strips were mounted in 20 ml organ bahts containing Krebs-Henseleit solution at 37oC continuously gassed with 95% O2 and 5% CO2. Cumulative concentration-effect curves were obtained for 5-HT, carbachol, KCl or CaCl2 . Second curves in test tissues were obtained in the presence of ouabain (10-5M) or amiloride (10-5M). Second curves for 5-HT and carbachol were also obtained in K+ free solution or a low Na+ solution. In addition, second curves for KCl were generated in a low Na+.
Results: The maximal effects of spasmogens tested were significantly increased in the presence of ouabain. The sensitivity of the preparations were increased to the carbachol, KCl and CaCl2 by ouabaine. In the presence of K+-free solution, the pD2 values of 5-HT and carbachol did not change. The maximal effects of 5-HT were increased by K+-free solution. Low Na+ solution did not alter the contractile responses to 5-HT and KCl, but depressed those to carbachol. Their pD2 values were not significantly changed by low Na+ solution. The pD2 values and maximal effects of KCl and CaCl2 were not changed by amiloride. In the presence of amiloride the maximal effects of 5-HT and carbachol were depressed and the sensitivity of preparations were decreased to these spasmogens. Responses to 5-HT and carbachol in Ca++-free (0.1 M EGTA) solution were increased by incubation with ouabain. Amiloride failed to depress the contractions produced by 5-HT and carbachol in Ca++-free (0.1 mM EGTA) solution.Conclusion: These results suggest that calf coronary artery possess Na+/Ca++ exchange system and Na+ channel inhibitors affect contractions of 5-HT, carbachol KCl or CaCl2 in this tissues.Keywords: Coronary artery, Serotonin, Carbachol,
Ouabaine, AmilorideTurkiye Klinikleri J Med Sci 2000, 20:334-340
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