<em>In vivo</em> model of Hirschsprung-associated enterocolitis using benzalkonium chloride

Abstract

BACKGROUND Hirschsprung-associated enterocolitis (HAEC) is a life-threatening complication of Hirschsprung’s disease. Studies using animal models on the pathogenesis of HAEC are limited. Thus, this study aimed to establish a rat model of HAEC using topical application of 0.1% benzalkonium chloride (BAC) in the sigmoid colon.&#x0D; METHODS 55 male Sprague Dawley rats aged 10−12 weeks old were separated into 11 groups. The control group (n = 5) was euthanized on day-7, and the other 10 groups (n = 5 in each group) treated with 0.1% BAC in the sigmoid colon for 15 min to induce Hirschsprung’s disease were euthanized on day-7, -10, -12, -14, -17, -19, -21, -23, -25, and -28. The sigmoid colon was excised, fixed in formalin, and sectioned for histological examinations with hematoxylin and eosin staining. The degree of HAEC was compared within all groups.&#x0D; RESULTS Rats that were sacrificed on day-7 to -12 showed the 1st degree or early HAEC, which was most likely caused by BAC application. The 2nd degree of HAEC occurred in rats that were sacrificed on day-14 that showed a macrophage infiltration in the sigmoid colon, thus fulfilled the initial criteria for HAEC (p = 0.0025 versus control). The degree of enterocolitis increased with time, and the highest degree was found in rats that were sacrificed on day-28 (p&lt;0.001 versus control).&#x0D; CONCLUSIONS Topical application of 0.1% BAC for 15 min was successfully produced HAEC model in rats, which was occurred on day-14 after the application. This model provides a useful resource for further research on the pathogenesis of HAEC.

Paneth Cell Hyperplasia and Metaplasia in Hirschsprung-associated Enterocolitis in An Aganglionosis Rat Model

“…HSCR was induced in rats by applying 0.1% benzalkonium chloride (BAC) (Sigma Aldrich, St. Louis, MO, USA) topically to the sigmoid colon as described previously to induce aganglionosis. (17) After being anesthetized, laparotomy was performed on rats weighing 150-200 g and the 1 cm of sigmoid colon was wrapped with 10 x 20 mm of paper gauze. The gauze was given three drops of 0.1% BAC solution every 5 min to prevent bowel dehydration, and this treatment was carried out every 15 min.…”

“…The enterocolitis degree was assessed as follows: normal and no evidence of injury=0; crypt dilation and mucin retention=1; cryptitis, crypt abscess and macrophageneutrophil infiltration=2; multiple crypt abscess=3; fibrinopurulent debris and mucosa alteration=4; necrosis and transluminal perforation=5. (17)(18)(19)…”

Paneth cells disruption and intestinal dysbiosis contribute to the development of Hirschsprung-associated enterocolitis in a benzalkonium chloride-induced Hirschsprung’s disease rat model

“…Serosal application of BAC with various concentrations has been widely used to induce HSCR in experimental animals [6,[15][16][17]. In the present study, we used 0.1% BAC concentrations to determine myenteric denervation and aganglionosis.…”