Kigata Tetsuhito, Lu Xizi, Shibata Hideshi, Kobayashi Yasushi
Department of Anatomy and Neurobiology, National Defense Medical College, Tokorozawa, Saitama 359-8513, Japan.
Laboratory of Veterinary Anatomy, Faculty, and Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
Ann Anat. 2023 Apr;247:152067. doi: 10.1016/j.aanat.2023.152067. Epub 2023 Feb 6.
The cranial mesenteric artery exhibits a species-specific ramification pattern that adapts to the morphology of the intestinal tract. The degu is a strictly herbivorous rodent with a well-developed large intestine with a spiral loop in the ascending colon; therefore, the cranial mesenteric artery likely demonstrates a degu-specific ramification pattern. Thus, we traced the cranial mesenteric artery to establish the detailed ramification pattern of the branches.
Eighteen male degus were injected with 0.3-0.8 ml of a latex mixture and water at a 1:1 ratio in conjunction with red acrylic paint coloring using a catheter inserted into the thoracic aorta. The cranial mesenteric artery was traced using a surgical microscope and photographed using a digital camera.
The arteries emerging from the cranial mesenteric artery exhibited frequent variations in number, distribution area, anastomosis pattern, and branching order. In the most frequent cases (22%), the cranial mesenteric artery sequentially gave rise to caudal pancreaticoduodenal, middle colic, right colic, jejunal, and ileocolic arteries. The right and middle colic arteries exhibited four different ramification patterns. In the most common cases (67%), the middle and right colic arteries emerged independently from the cranial mesenteric artery. The former was distributed to the transverse and descending colon, whereas the latter sent branches to the spiral loop of the ascending colon.
The complex ramification pattern of the right colic artery in the degu may be an adaptation to the characteristic running pattern of the ascending colon. Thus, we present the first comprehensive report of the arterial branching pattern of the cranial mesenteric artery in the degu.
肠系膜上动脉呈现出一种物种特异性的分支模式，以适应肠道的形态。八齿鼠是一种严格的草食性啮齿动物，大肠发达，升结肠有螺旋襻；因此，肠系膜上动脉可能呈现出八齿鼠特有的分支模式。因此，我们追踪了肠系膜上动脉以确定其分支的详细模式。
18只雄性八齿鼠通过插入胸主动脉的导管注射0.3 - 0.8毫升1:1比例的乳胶混合物和水，并加入红色丙烯酸涂料进行染色。使用手术显微镜追踪肠系膜上动脉，并用数码相机拍照。
从肠系膜上动脉发出的动脉在数量、分布区域、吻合模式和分支顺序上经常出现变异。在最常见的情况（22%）下，肠系膜上动脉依次发出胰十二指肠后动脉、结肠中动脉、结肠右动脉、空肠动脉和回结肠动脉。结肠右动脉和结肠中动脉呈现出四种不同的分支模式。在最常见的情况（67%）下，结肠中动脉和结肠右动脉独立地从肠系膜上动脉发出。前者分布于横结肠和降结肠，而后者向升结肠的螺旋襻发出分支。
八齿鼠结肠右动脉复杂的分支模式可能是对升结肠特征性走行模式的一种适应。因此，我们首次全面报道了八齿鼠肠系膜上动脉的动脉分支模式。
