Department of Medicine, The University of Chicago, Chicago, Illinois, USA.
Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.
J Clin Invest. 2023 Aug 1;133(15):e166185. doi: 10.1172/JCI166185.
An increasing number of studies have demonstrated that disease states of the endocrine or exocrine pancreas aggravate one another, which implies bidirectional blood flow between islets and exocrine cells. However, this is inconsistent with the current model of unidirectional blood flow, which is strictly from islets to exocrine tissues. This conventional model was first proposed in 1932, and it has never to our knowledge been revisited to date. Here, large-scale image capture was used to examine the spatial relationship between islets and blood vessels in the following species: human, monkey, pig, rabbit, ferret, and mouse. While some arterioles passed by or traveled through islets, the majority of islets had no association with them. Islets with direct contact with the arteriole were significantly larger in size and fewer in number than those without contact. Unique to the pancreas, capillaries directly branched out from the arterioles and have been labeled as "small arterioles" in past studies. Overall, the arterioles emerged to feed the pancreas regionally, not specifically targeting individual islets. Vascularizing the pancreas in this way may allow an entire downstream region of islets and acinar cells to be simultaneously exposed to changes in the blood levels of glucose, hormones, and other circulating factors.
越来越多的研究表明，内分泌或外分泌胰腺的疾病状态会相互加重，这意味着胰岛和外分泌细胞之间存在双向血流。然而，这与目前严格从胰岛流向外分泌组织的单向血流模型不一致。这个传统模型最初是在 1932 年提出的，迄今为止，它从未被重新审视过。在这里，使用大规模图像捕获技术检查了以下物种的胰岛和血管之间的空间关系：人、猴、猪、兔、雪貂和鼠。虽然一些小动脉经过或穿过胰岛，但大多数胰岛与它们没有关联。与小动脉直接接触的胰岛的大小明显更大，数量也更少。在胰腺中，毛细血管直接从小动脉分支出来，在过去的研究中被标记为“小动脉”。总的来说，小动脉出现是为了区域性地给胰腺供血，而不是专门针对单个胰岛。以这种方式给胰腺供血可以使整个下游胰岛和腺泡细胞区域同时暴露在血糖、激素和其他循环因子的血液水平变化中。
