Madsen K L, Tavernini M M, Yachimec C, Mendrick D L, Alfonso P J, Buergin M, Olsen H S, Antonaccio M J, Thomson A B, Fedorak R N
Division of Gastroenterology, University of Alberta, Edmonton, Canada.
Am J Physiol. 1998 Jan;274(1):G96-102. doi: 10.1152/ajpgi.1998.274.1.G96.
Stanniocalcin (STC) is an anti-hypercalcemic glycoprotein hormone previously identified in the corpuscles of Stannius in bony fish and recently in the human genome. This study undertook to express human STC in Chinese hamster ovary (CHO) cells and to determine its effects on calcium and phosphate absorption in swine and rat intestine. Unidirectional mucosal-to-serosal (Jm-->s) and serosal-to-mucosal (Js-->m) 45Ca and 32P fluxes were measured in vitro in duodenal tissue in voltage-clamped Ussing chambers. Addition of STC (10-100 ng/ml) to the serosal surface of the duodenum resulted in a simultaneous increase in calcium Jm-->s and Js-->m fluxes, with a subsequent reduction in net calcium absorption. This was coupled with an STC-stimulated increase in phosphate absorption. Intestinal conductance was increased at the highest dose of STC (100 ng/ml) in swine tissue. The addition of STC to the mucosal surface had no effect on calcium and phosphate fluxes. STC at doses of 10-1,000 ng/ml had no effect on short-circuit current in any region of the rat intestine. In conclusion, human recombinant STC decreases the absorption of calcium and stimulates the absorption of phosphate in both swine and rat duodenum. STC is a novel regulatory protein that regulates mammalian intestinal calcium and phosphate transport.
鲽源钙调节蛋白（STC）是一种抗高钙血症糖蛋白激素，先前在硬骨鱼的斯坦尼小体中被发现，最近在人类基因组中也有发现。本研究致力于在中国仓鼠卵巢（CHO）细胞中表达人STC，并确定其对猪和大鼠肠道钙和磷吸收的影响。在电压钳制的Ussing室中，体外测量十二指肠组织中单向黏膜到浆膜（Jm-->s）和浆膜到黏膜（Js-->m）的45Ca和32P通量。向十二指肠浆膜表面添加STC（10 - 100 ng/ml）会导致钙Jm-->s和Js-->m通量同时增加，随后净钙吸收减少。这伴随着STC刺激的磷吸收增加。在猪组织中，最高剂量的STC（100 ng/ml）会增加肠道电导率。向黏膜表面添加STC对钙和磷通量没有影响。10 - 1000 ng/ml剂量的STC对大鼠肠道任何区域的短路电流都没有影响。总之，人重组STC会降低猪和大鼠十二指肠中钙的吸收并刺激磷的吸收。STC是一种调节哺乳动物肠道钙和磷转运的新型调节蛋白。
