The effect of blockage of the gastrointestinal tract upon urine formation in a marine teleost, Myoxocephalus octodecimspinosus

✍ Scribed by Grafflin, Allan L. ;Ennis, David

• Publisher: Wiley (John Wiley & Sons)
• Year: 1934
• Tongue: English
• Weight: 706 KB
• Volume: 4
• Category: Article
• ISSN: 0095-9898
• DOI: 10.1002/jcp.1030040302

✦ Synopsis

Smith ('30, '32) has shown that marine teleosts swallow relatively large quantities of sea water, which undergoes absorption in the gastro-intestinal tract. Most of the ingested water, Na, K and Cl are absorbed from the intestine, leaving a residue rich in Mg and S8, and approximately isotonic with the blood. The greater fraction of the absorbed water, Na, K and C1 is excreted extra-renally, leaving a moiety of water for the excretion of the characteristically isotonic urine, in which Mg and SO, derived from intestinal absorption predominate. It is by this cycle that blood composition and urine formation are maintained.

The present experiments were designed to examine the effects of the operative obstruction of the gastro-intestinal tract at the pylorus upon the maintenance of body weight, the rate of urine excretion, and the composition of the urine.

The common sculpin, Myoxocephalus octodecimspinosus, was used exclusively in these experiments. Fish freshly caught and carefully removed from the hook were anesthetized with urethane.l A small midline incision was made in METHODS ~~_ _ _ _ _ _ _ _ _ _ _ _ ~ lAi~estliesia was iiiduced rapidly by a 1 per cent solution of urethane in sea water and maintaiued through the operation by a 0.25 per cent solution of urethane supplied continuously to the operating box from a large aspirator bottle, and well aerated with compressed air. A detailed description of the operating box will be given in a later paper.