, Chicago, IL, USA) [26]. Secretions form a thin film on the mucosa and allow the evolution of carbon dioxide (CO2) formed from acid�Cbase interactions. Therefore, the esophageal bicarbonate buffer value would be equilibrated with CO2 tension of the lumen [26]?and?[27]. This was the rationale for choosing titration to pH of 4.0 for assessment of esophageal bicarbonate in an open system (without covering with a layer of liquid paraffin oil) with continuous CO2-free bubbling. The bicarbonate concentration was calculated using the difference in the amount of acid initially required to titrate the sample from its starting pH to pH 4.0 and the amount of base required to back-titrate the sample to its original pH after development of Selleckchem Dolutegravir the CO2. The difference between the back-titration from pH 4.0 to its original starting value and the similar run of the buffer-free blank solution was used to calculate non-bicarbonate buffers [26]?and?[27]. In addition, this methodology was always validated by the titration of known concentrations of bicarbonate and non-bicarbonate in the standard solutions. Salivary glycoconjugate (predominantly mucin) was measured using the periodic acid Schiff (PAS) methodology [9]?and?[24]. Salivary EGF was assessed by RIA using a commercially available kit (Amersham, Arlington Heights, IL, USA) [10], [11], [16]?and?[19]. Salivary TGF�� was recorded using a commercially available RIA kit based on highly specific sheep anti-human TGF�� antibodies Talazoparib solubility dmso (Biomedical Technologies Inc., Stoughton, MA, USA) [26]?and?[28]. The separation between bound and unbound TGF�� was performed using donkey anti-sheep IgG and polyethylene glycol (PEG). Human recombinant TGF�� was used for a standard curve. All samples were centrifuged at 4?��C and 3000?rpm for 20?min, which are the conditions required to spin down cellular debris, plasma membrane sheets and nuclei. Salivary PGE2 was measured using a RIA kit (Amersham, Arlington Heights, MA, USA) [25]. This RIA method is based on highly specific antibodies directed to oximated form of PGE2. Salivary protein was monitored by the Lowry methodology [24]. Data was presented as mean values of salivary collections at basal level, during parafilm CAPNS1 chewing, following placement of tubing, following inflation of balloons and during the perfusion intervals. All results were expressed as means?��?SEM. Statistical analysis by ANOVA was performed using ��-Stat software (Jandel Scientific, San Rafael, CA, USA). Salivary volume in BE and controls was similar. Salivary pH in BE was significantly lower than CTRL group during intraesophageal mechanical stimulation with tubing (7.52?��?0.10 vs. 8.02?��?0.06, p?<?0.001) and balloons (7.44?��?0.11 vs. 7.93?��?0.09, p?<?0.01), as well as during intraesophageal chemical stimulation with initial NaCl (7.59?��?0.08 vs. 8.01?��?0.08, p?<?0.001), HCl (7.62?��?0.10 vs. 7.90?��?0.</div>
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