Animal model of rectal prolapse in rats

Animal model of rectal prolapse in rats：

Animal model of rectal prolapse in rats：

1、 Model building method

1. ‌Surgical induction method‌

• ‌operating steps‌：

• After anesthesia, the midline of the abdomen is incised 2-3cm, the rectum is freed, and the lateral ligaments or pelvic floor fascia are partially cut to reduce rectal fixation.

• Retain a portion of the free segment of the rectum during suturing, or implant elastic material to restrict retraction and simulate prolapse
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• ‌characteristicDirectly destroying supporting structures, simulating anatomical changes, but with significant surgical trauma
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2. ‌Chemical stimulation method‌

• ‌operating steps‌：

• Insert the catheter into the rectum 6-8cm, inject 4% acetic acid for 30 seconds, and rinse with physiological saline
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• Postoperative observation of mucosal inflammation, ulcers, and prolapse like changes
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• ‌characteristicEasy to operate and quickly induce mucosal injury, but the pathological features are more acute
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3. ‌Mechanical pressure combined with hormone intervention method‌

• ‌operating steps‌：

• Ovarian resection simulates postmenopausal hormone changes, combined with vaginal balloon dilation (3mL of physiological saline compression for 4 hours)
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• ‌characteristicMore closely related to the multifactorial pathogenesis of humans, suitable for studying chronic pathological processes
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4. ‌Improved device auxiliary method‌

• ‌New equipment‌：

• Quantify pressure induced prolapse using an electric puller and F10 catheter balloon device (constant pressure inflation+mechanical traction)
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• ‌advantageStandardize pressure parameters to reduce human error
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2、 Model validation and evaluation

1. ‌Behavioral observation‌

• Record the frequency of bowel movements, responsible behavior, and anal prolapse
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2. ‌imaging examination‌

• Observation of rectal mucosal intussusception using X-ray defecography or micro endoscopy
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3. ‌Histopathology‌

• HE staining was used to detect mucosal layer separation and inflammatory infiltration; Masson staining to evaluate changes in collagen fibers
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4. ‌Molecular testing‌

• QPCR/Western blot analysis of type I/III collagen (COL1A1, COL3A1) and TGF - β 3 expression

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