Antikolinesteraz ilaçların sıçan mide fundus düz kası üzerine anti-muskarinik etkileri

Çalışmamızda neostigmin, piridostigmin ve edrofonyumun yüksek dozlarında sıçan mide fundus düz kas dokularındaki muskarinik reseptörleri inhibe edip etmediklerini ve bu ilaçların sıçan intestinal düz kas kasılmaları üzerine olası dual etkilerini inceledik. Çalışmamızın başlangıcında ilk olarak betanekole kümülatif olarak kontrol kasılma yanıtları alındı. Takiben antikolinesterazların her bir konsantrasyonu sonrasında betanekol için kümülatif derişim-yanıt eğrileri elde edildi. Antikolinesterazlardan hiçbirisi ilk üç derişimlerinde (sırasıyla 1, 10 ve 100 µM), betanekol kasılma yanıtlarında herhangi bir güçlenmeye yol açmadı (p >0,05). Fakat 1mM’lık en yüksek derişimlerinde, neostigmin, edrofonyum ve piridostigmin, mide düz kas striplerinde betanekolle uyarılan düz kas kasılmalarını zayıflattı (p ≤0,05; eşleştirilmiş Student’s t test). Sonuçlar antikolinesterazların sıçan mide fundus preparatlarındaki kolinerjik kasılma yanıtları üzerinde dual etkili olmadıklarını düşündürmektedir. Antikolinesterazlar yüksek dozlarında, mide fundus düz kas kasılmaları üzerinde antimuskarinik etkilere yol açabilirler.

Anahtar Kelimeler:

Kolinesteraz inhibitörleri, Kas, düz, Kas kasılması, Mide fundusu, Sıçan, Wistar, Piridostigmin bromit, Modeller, hayvan, Betanekol

The antimuscarinic effects of anticholinesterase drugs on rat gastric fundus smooth muscle

We investigated whether neostigmine, piridostigmine and edrophonium in larger doses inhibit muscarinic receptors of rat gastric fundus and whether those drugs have dual effects on rat intestinal smooth muscle contractions. Initially control contractile responses in a cumulative manner obtained for bethanechol, Following this, four different concentrations of each anticholinesterases (respectively 1, 10, 100 and 1000 µM) injected into the organ bath solution where smooth muscle strips attached. After each concentration of anticholinesterases, cumulative dose-response curves for bethanechol has been obtained. Our results show that none of the three anticholinesterases did cause any potentialization on contractile responses for bethanechol at their first three concentrations (respectively 1, 10 and 100 µM). But at their highest concentration such as 1000 µM, neostigmine, edrophonium and piridostigmine attenuated the bethanechol induced contractile responses (p ≤ 0,05; paired samples t test). These results suggest that anticholinesterases do not have dual effects on bethanechol induced contractile responses of rat gastric fundus smooth muscle preparations. Larger doses of anticholinesterases may evoke antimuscarinic effects on intestinal smooth muscle contractions.

Keywords:

Cholinesterase Inhibitors, Muscle, Smooth, Muscle Contraction, Gastric Fundus, Rats, Wistar, Pyridostigmine Bromide, Models, Animal, Bethanechol,

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