First Department of Medicine, University of Szeged Szeged, Hungary.
Front Physiol. 2011 Jul 14;2:36. doi: 10.3389/fphys.2011.00036. eCollection 2011.
Acinar and ductal cells of the exocrine pancreas form a close functional unit. Although most studies contain data either on acinar or ductal cells, an increasing number of evidence highlights the importance of the pancreatic acinar-ductal functional unit. One of the best examples for this functional unit is the regulation of luminal pH by both cell types. Protons co-released during exocytosis from acini cause significant acidosis, whereas, bicarbonate secreted by ductal cells cause alkalization in the lumen. This suggests that the first and probably one of the most important role of bicarbonate secretion by pancreatic ductal cells is not only to neutralize the acid chyme entering into the duodenum from the stomach, but to neutralize acidic content secreted by acinar cells. To accomplish this role, it is more than likely that ductal cells have physiological sensing mechanisms which would allow them to regulate luminal pH. To date, four different classes of acid-sensing ion channels have been identified in the gastrointestinal tract (transient receptor potential ion channels, two-pore domain potassium channel, ionotropic purinoceptor and acid-sensing ion channel), however, none of these have been studied in pancreatic ductal cells. In this mini-review, we summarize our current knowledge of these channels and urge scientists to characterize ductal acid-sensing mechanisms and also to investigate the challenge of the acinar acid load on ductal cells.
胰腺外分泌腺的腺泡和导管细胞形成了一个紧密的功能单位。虽然大多数研究都包含关于腺泡或导管细胞的数据，但越来越多的证据强调了胰腺腺泡-导管功能单位的重要性。这个功能单位的一个最好的例子是两种细胞类型对管腔 pH 的调节。来自腺泡的胞吐作用共同释放的质子会导致明显的酸中毒，而导管细胞分泌的碳酸氢根会使管腔碱化。这表明，导管细胞分泌碳酸氢盐的第一个作用，也许是最重要的作用之一，不仅是中和从胃进入十二指肠的酸性食糜，还中和腺泡细胞分泌的酸性物质。为了实现这一作用，导管细胞很可能具有生理感应机制，使它们能够调节管腔 pH。迄今为止，在胃肠道中已经鉴定出四类不同的酸感应离子通道（瞬时受体电位离子通道、双孔钾通道、离子型嘌呤能受体和酸感应离子通道），但尚未在胰腺导管细胞中进行研究。在这篇迷你综述中，我们总结了目前对这些通道的了解，并敦促科学家们对导管的酸感应机制进行特征描述，并研究腺泡酸负荷对导管细胞的挑战。
