Calcium chloride bihydrate (CaCl2.2H2O), magnesium chloride hexahydrate (MgCl2.6H2O) and glucose (C6H12O6) were purchased from Vetec. Sodium bicarbonate (NaHCO3) was purchased from Fmaia. Sodium chloride (NaCl) and potassium chloride (KCl) were purchased from Química Moderna. Monopotassium phosphate (NaH2PO4), sodium hydroxide (NaOH) and hydrochloric acid (HCl) were purchased from Nuclear. Carbamylcholine hydrochloride (CCh) was purchased from Merck. Formaldehyde was purchased from Vetec. Thiobarbituric acid, tetramethoxypropane, perchloric acid, Mayer's haematoxylin and eosin were purchased from Sigma. Carbogen mixture (95% O2 and 5% CO2) was obtained from White Martins (Brazil).
The CCh was used to mimic the cholinergic stimulation that happens on the intestinal smooth muscle promoted by the myenteric plexus [23 (link),24 (link)]. The KCl was employed to simulate the pacemaker of interstitial cells of Cajal located at the boundaries and in the substance of the inner, circular muscle layer, from which they spread to the outer, longitudinal muscle layer [25 ,26 (link)].
The CCh was used to mimic the cholinergic stimulation that happens on the intestinal smooth muscle promoted by the myenteric plexus [23 (link),24 (link)]. The KCl was employed to simulate the pacemaker of interstitial cells of Cajal located at the boundaries and in the substance of the inner, circular muscle layer, from which they spread to the outer, longitudinal muscle layer [25 ,26 (link)].