OPTIMAL NAOH CONCENTRATION IN THE EXPERIMENTAL MODEL OF BENIGN ESOPHAGEAL STENOSIS IN RATS

Aims:

The optimal concentration of alkali applied which can achieve both extremely satisfying success rate of establishing experimental models and high survival rate still needs further investigation. Our study aimed to investigate the optimal concentration of sodium NaOH to establish a BES model in rats.

Methods:

As much as 58 healthy male Sprague-Dawley rats, 7-week old, were randomly divided into seven groups: A group (Control group) (n = 6), B group (Sham-operated group) (n = 6), C group (5% NaOH group) (n = 6), D group (10% NaOH) (n = 6), E group (20% NaOH) (n = 11), F group (30% NaOH) (n = 11) and G group (40% NaOH) (n = 12). Except for the control group, each rat in other groups experienced laparotomy operation and the distal esophagus was ligatured. Then placebo or different concentrations of NaOH was perfused into the distal esophagus by a stomach cleaning apparatus. All rats were executed on the 15^th day after the operation, and the tissues of distal esophagus of each rat were collected. Finally, the survival rate, the body weight increment, symptoms of esophageal stenosis and histopathologic change were evaluated.

Results:

Groups F and G had obviously lower survival rate (27% and 0, respectively) and more weight loss (42% and N/A). Obvious symptoms of esophageal stenosis were observed in those groups in which the concentration of NaOH were equal to or more than 10% (33% in the 10% NaOH group, 45% in the 20% NaOH group, 55% in the 30% NaOH group and 92% in the 40% NaOH group). These four groups were stained with Masson. The highest median value of LA/TA was found in group B, and the LA/TA was significant lower in group D, E, F than groups A and B.

Conclusions:

By estimating success rate of modeling and survival rate after operations at the same time, we recommended a concentration of 10% NaOH was required to establish a effective and stable BES model in rats.