Forster M E, Fenwick J C
Department of Zoology, University of Canterbury, Christchurch, New Zealand.
Gen Comp Endocrinol. 1994 Apr;94(1):92-103. doi: 10.1006/gcen.1994.1063.
A factor present in the homogenate of the corpuscles of Stannius from a teleost, the longfin eel Anguilla dieffenbachii, showed calcitropic effects in an agnathan, the hagfish Eptatretus cirrhatus. This factor greatly increased calcium efflux from an isolated perfused gill pouch preparation and had no effect on calcium influx. Hagfish regulated plasma total calcium at a concentration which was about 50% of that of the ambient seawater. Intact hagfish had rates of calcium influx and efflux which were similar to those recorded in teleosts. Hagfish are thus similar to teleosts to the extent that they can and do maintain a plasma calcium concentration which is quite different from that of the ambient medium. They also resemble teleosts in that transepithelial calcium fluxes across the hagfish gill pouches respond to extracts of Stannius corpuscles. Hagfish, however, are quite unlike teleosts in that the Stannius corpuscle extract stimulates calcium efflux rather than inhibiting calcium influx.
一种存在于硬骨鱼——长鳍鳗鲡（Anguilla dieffenbachii）的斯坦尼斯小体匀浆中的因子，在无颌类动物——盲鳗（Eptatretus cirrhatus）中显示出促钙效应。该因子极大地增加了离体灌注鳃囊标本的钙外流，而对钙内流没有影响。盲鳗将血浆总钙调节在约为周围海水浓度50%的水平。完整的盲鳗的钙内流和外流速率与硬骨鱼中记录的速率相似。因此，盲鳗在能够且确实维持与周围介质不同的血浆钙浓度这一点上与硬骨鱼相似。它们在穿过盲鳗鳃囊的跨上皮钙通量对斯坦尼斯小体提取物有反应这方面也与硬骨鱼相似。然而，盲鳗与硬骨鱼非常不同，因为斯坦尼斯小体提取物刺激钙外流而不是抑制钙内流。
