Abstract
In attempting to use the Bayliss-Fee oxygenator in isolated mammalian heart studies it was found that the life of the preparation was very short, as little as 30 minutes. The coronary flow was found to diminish progressively and the hearts failed rapidly. In investigating possible causes it was found that considerable Al(OH)3 accumulated in the system. The oxygenator is made of cast aluminum. The corrosion of the aluminum metal obviously led to the production of Al(OH)3. Therefore all surfaces were covered with a uniform thin coat of clear lacquer. The life of the isolated heart in the system was thereby greatly prolonged.
To elucidate the mechanism of the effect of aluminum two types of experiments were performed. First, frog hearts were set up on Straub cannulæ and Ringer containing 200-400 mg % of Al(OH)3, as alumina cream, was substituted for the plain Ringer placed in the cannula for control observations. These amounts of Al(OH)3 had no toxic effects upon the frog hearts, rather there was a slight tonic effect and the hearts kept beating longer than did simultaneous controls.
A second group of experiments were run upon rabbit hearts perfused by the Langendorff technic. There was a trace of blood in the perfusion fluid in the first experiments. Addition of 2 cc of 2% Al(OH)3 in Ringer to the perfusion fluid caused almost immediate stoppage of the heart, and of the flow of fluid through the coronaries. In other experiments the heart was perfused with Ringer containing no blood and the perfusate discarded. It was washed with 1500 cc of Ringer, after which the emerging fluid was protein-free by the tungstic acid test.
Addition of 15cc of 2% Al(OH)3 thereafter did not stop the heart, although the amplitude of contraction was somewhat diminished.
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