İzole dana koroner arterinde muskarinik agonistlerle oluşan cevaplar ve bu cevapların kalsiyumla ilişkisi
Küçük Resim Yok
Tarih
1996
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Necmettin Erbakan Üniversitesi Meram Tıp Fakültesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu in vitro çalışmada, dana koroner arterinde asetilkolin ve karbakol ile oluşan kasılma cevaplarının Ca++ ile ilişkisi ve asetilkolinle alman kasılma cevapları üzerine L-NAME'nin etkileri araştırılmıştır. Arterlerden elde edilen stripler, temperatürü 37°C'de sabit tutulan ve % 95 02"% 5 CO2 karışımı ile sürekli gazlandırılan Krebs-Henseleit solüsyonu içerisine alınarak agonist ve antagonist ilaçlar deneysel prosedüre uygun olarak uygulanmıştır. Asetilkolin ve karbakol bu dokuda doza bağımlı ve tekrarlanabilir nitelikte kasılma cevapları oluşturmuş ve bu cevaplar atropin ile non-kompetitif tarzda antagonize edilmiştir. Kalsiyumsuz ortamda, 10"6 M asetilkolin ve karbakol ile alman kasılma cevapları kontrol cevapların sırasıyla, % 23.76 ± 3.17 ve 16.27 ± 3.93 u oranında olmuş ve ortama artan konsantrasyonlarda kalsiyum ilavesiyle bu iki agonistle alman cevaplar artmıştır. Kalsiyum ilavesiyle elde edilen bu cevap artışları verapamil (10-8 - 10"6 M) ile doza bağımlı olarak inhibe edilmiştir. Serotonin ile prekontrakte edilen dokulara kümülatif tarzda uygulanan asetilkolin serotonin cevaplarını % 18.5 ± 1.72 oranında artırmış, buna karşın asetilkolin ilavesinden önce ortama L-NAME (3xl0"4 M) konulması ile bu artış % 47.7 ± 10.52 oramnda gerçekleşmiştir. KCI ile kasılabilirliği tesbit edilen dokuda, kümülatif tarzda uygulanan asetilkolinle KCI cevaplarının % 39.95 ± 10.61'i oranında bir kasılma cevabı elde edilmiş, buna karşın asetilkolin ilavesinden önce ortama L-NAME konulması ile bu oran % 32.26 ± 10.7 şeklinde olmuştur. Kasılma cevabındaki bu azalma anlamsızdır (P>0.05). Bu sonuçlar, asetilkolin ve karbakol kasılmalarının doza bağımlı ve tekrarlanabilir nitelikte olduğunu, atropin ile non-kompetitif tarzda antagonize edildiğini, agonistlere bağlı cevaplarda ekstra - ve intraselüler kalsiyumun rol oynadığını ve ayrıca bazal tonusa sahip dokuda asetilkolinle elde edilen kasılma cevaplarının L-NAME'den etkilenmediğini göstermektedir.
Muscarinic agonists-induced responses of isolated bovine coronary artery and their dependence on Ca^+, In this in vitro study, the role of Ca^+ of the acetylcholine and carbachol induced contractions and the effects of L-NAME on the acetylcholine-induced contractile responses were investigated. The strips obtanied from arteries were suspended in Krebs-Henseleit solution maintained at 37°C and bubbled with a gas mixture containing 95 % oxygen and 5 % carbondioxide then agonists and antagonists were applied according to the experimental procedure. Acetylcholine and carbachol caused dose-dependent and reproducible contractions in this tissue and these responses were non-competitively antagonized with atropin. In Ca^+-free medium, acetylcholine and carbachol-induced contractions were 23.76±3.17 % and 16.27±3.93 % of the control responses, respectively and the responses to both agonists were increased by re-addition of cumulative consentrations of Ca. The increased responses obtained with Cer+ re-addition were inhibited with verapamil (10"°-10""M) in a dose-dependent manner. In serotonin pre-contracted tissues, cumulative addition of acetylcholine caused the increase in serotonin responses. This augmented responses was found to be as 18.57±1.72 % of initial serotonin contraction. Pre-incubation with L-NAME significantly augmented this additional contractions. In the tissue that contractility by KC1 was detected acetylcholine-induced contraction was 39.95±10.61 % of the KC1 responses, in spite of this by the addition of L-NAME to the medium before acetylcholine-addition, this ratio was 32.26±10.7 %. The decreasing of the contractile responses was insignificant (p>0.05). 26The results suggest that the contractions with acetylcholine and carbachol were dose-dependent and reproducible and antagonized in a non-competitive manner by atropin and both extra- and intracellular Ca^+ had a role in agonists-induced responses In the resting tension, the acetylcholine-induced contractions were not effected by L-NAME.
Muscarinic agonists-induced responses of isolated bovine coronary artery and their dependence on Ca^+, In this in vitro study, the role of Ca^+ of the acetylcholine and carbachol induced contractions and the effects of L-NAME on the acetylcholine-induced contractile responses were investigated. The strips obtanied from arteries were suspended in Krebs-Henseleit solution maintained at 37°C and bubbled with a gas mixture containing 95 % oxygen and 5 % carbondioxide then agonists and antagonists were applied according to the experimental procedure. Acetylcholine and carbachol caused dose-dependent and reproducible contractions in this tissue and these responses were non-competitively antagonized with atropin. In Ca^+-free medium, acetylcholine and carbachol-induced contractions were 23.76±3.17 % and 16.27±3.93 % of the control responses, respectively and the responses to both agonists were increased by re-addition of cumulative consentrations of Ca. The increased responses obtained with Cer+ re-addition were inhibited with verapamil (10"°-10""M) in a dose-dependent manner. In serotonin pre-contracted tissues, cumulative addition of acetylcholine caused the increase in serotonin responses. This augmented responses was found to be as 18.57±1.72 % of initial serotonin contraction. Pre-incubation with L-NAME significantly augmented this additional contractions. In the tissue that contractility by KC1 was detected acetylcholine-induced contraction was 39.95±10.61 % of the KC1 responses, in spite of this by the addition of L-NAME to the medium before acetylcholine-addition, this ratio was 32.26±10.7 %. The decreasing of the contractile responses was insignificant (p>0.05). 26The results suggest that the contractions with acetylcholine and carbachol were dose-dependent and reproducible and antagonized in a non-competitive manner by atropin and both extra- and intracellular Ca^+ had a role in agonists-induced responses In the resting tension, the acetylcholine-induced contractions were not effected by L-NAME.
Açıklama
Anahtar Kelimeler
Kalsiyum, Koroner damarlar, Reseptörler
Kaynak
WoS Q Değeri
Scopus Q Değeri
Cilt
Sayı
Künye
Karabacak, H. İ. (1996). İzole dana koroner arterinde muskarinik agonistlerle oluşan cevaplar ve bu cevapların kalsiyumla ilişkisi. (Yayınlanmamış tıpta uzmanlık tezi) Necmettin Erbakan Üniversitesi, Meram Tıp Fakültesi Dahili Tıp Bilimleri Tıbbi Farmakoloji Anabilim Dalı, Konya.
