Hassan A Khalil1, Masae Kobayashi1, Puneet Rana1, Justin P Wagner1, Andrew Scott1, James Yoo2, James C Y Dunn3. 1. Department of Surgery, UCLA David Geffen School of Medicine, Los Angeles, California. 2. Department of Surgery, Tufts Medical Center, Boston, Massachusetts. 3. Department of Surgery, UCLA David Geffen School of Medicine, Los Angeles, California. Electronic address: jdunn@mednet.ucla.edu.
Abstract
BACKGROUND: Current transgenic animal models of Hirschsprung disease are restricted by limited survival and need for special dietary care. We used small animal colonoscopy to produce chemically ablated enteric nervous system in the distal colon and rectum of normal mice. MATERIALS AND METHODS: Adult C57BL/6 mice underwent colonoscopy with submucosal injection of 75-100 μL of saline (n = 2) or 0.002% (n = 2), 0.02% (n = 15), or 0.2% (n = 2) benzalkonium chloride (BAC). Each mouse received 1-3 injections in the distal colon and rectum. Mice were sacrificed on postprocedure day 7 or 28. Injection sites were analyzed histologically and with immunostaining for β-tubulin III. RESULTS: Submucosal injection of 0.02% BAC resulted in megacolon and obliteration of 82 ± 8.8% of myenteric ganglia at the injection site on postprocedure day 7 compared with normal colon. This effect was sustained until day 28. Injection of 0.002% BAC had little effect on the myenteric neuronal network at these time points. Multiple injections of 0.002% or 0.02% BAC (up to three injections per mouse) were well tolerated. Injection of 0.2% BAC caused acute toxicity or death. CONCLUSIONS: A novel model of chemically ablated enteric nervous system in the mouse colon and rectum is introduced. This model can be valuable in evaluating targeted cell delivery therapies for Hirschsprung disease.
BACKGROUND: Current transgenic animal models of Hirschsprung disease are restricted by limited survival and need for special dietary care. We used small animal colonoscopy to produce chemically ablated enteric nervous system in the distal colon and rectum of normal mice. MATERIALS AND METHODS: Adult C57BL/6 mice underwent colonoscopy with submucosal injection of 75-100 μL of saline (n = 2) or 0.002% (n = 2), 0.02% (n = 15), or 0.2% (n = 2) benzalkonium chloride (BAC). Each mouse received 1-3 injections in the distal colon and rectum. Mice were sacrificed on postprocedure day 7 or 28. Injection sites were analyzed histologically and with immunostaining for β-tubulin III. RESULTS: Submucosal injection of 0.02% BAC resulted in megacolon and obliteration of 82 ± 8.8% of myenteric ganglia at the injection site on postprocedure day 7 compared with normal colon. This effect was sustained until day 28. Injection of 0.002% BAC had little effect on the myenteric neuronal network at these time points. Multiple injections of 0.002% or 0.02% BAC (up to three injections per mouse) were well tolerated. Injection of 0.2% BAC caused acute toxicity or death. CONCLUSIONS: A novel model of chemically ablated enteric nervous system in the mouse colon and rectum is introduced. This model can be valuable in evaluating targeted cell delivery therapies for Hirschsprung disease.
Authors: Masae Kobayashi; Hassan A Khalil; Nan Ye Lei; Qianqian Wang; Ke Wang; Benjamin M Wu; James C Y Dunn Journal: Sci Rep Date: 2018-09-10 Impact factor: 4.379