52 THE ROLE OF ALGAE AND PLANKTON IN MEDICINE 



caused systolic arrest of the isolated perfused frog heart, but the uterus of 

 the virgin pig was unaffected. Oxygen consumption of various rat tissue 

 slices also remained unchanged. Steyn 258 " 260 reported marked blistering 

 of photosensitized animal skins, as well as extensive involvement of the 

 liver and the central nervous system. Post-mortem examinations showed 

 the lungs full of blood; the spleen enlarged; and the liver engorged and 

 dark red to black. In chronic cases, the liver was either yellow and soft, 

 or dark and brittle. Ashworth and Mason 272 were able to produce general- 

 ized cellular damage by administering Microcystis extract to rats. Especially 

 severe injury was noted in the parenchymal cells of the liver. Succes- 

 sive stages included acute parenchymatous, hydropic, and fatty de- 

 generation, followed by central lobular necrosis. If death did not ensue, 

 complete restoration of normal lobular architecture — without fibrosis — 

 took place in thirty days. The toxic alterations were comparable to those 

 produced by chloroform, phosphorus", and epidemic hepatitis. Similar 

 acute hydropic and necrotic changes were also seen in the heart and 

 kidneys, while microscopic hemorrhages and edema sometimes occurred 

 in the lungs. Ashworth and Mason felt that rapid death was due to shock 

 and circulatory collapse, while delayed demise was consequent to hepatic 

 insufficiency, renal failure, and diffuse cellular damage. Stewart and his 

 colleagues 268 reported fresh pulmonary hemorrhages and hepatic and 

 cardiac lesions in Ontario cattle dying after ingestion of Anabaena and 

 Microcystis scum. They found the same material lethal to pigeons and 

 rats. Pathological findings from Alberta were "dilatation of the heart" 

 and "mottled liver." 



As mentioned earlier, many non-algal poisons have been wrongly 

 suspected. In several cases, botulinus antitoxin was administered, to no 

 avail. Solutions of sodium nitrite and sodium thiosulfate given intraven- 

 ously assertedly produced recovery of some poisoned animals. Although 

 the various outbreaks are now known to have been algal in origin, the 

 specific nature of the toxins involved has certainly not been clear. Fitch 254 

 determined that the substances from Microcystis and Anabaena are non- 

 volatile, heat-stable when dry, stable in solution at ordinary temperatures, 

 but unstable when heated to 100°C. They are not electrolytes, alkaloids, or 

 toxalbumins. They are organic componds of low molecular weight, some- 

 what resistant to acid and alkaline solutions. The substances apparently 

 disappear when the algae putrefy. Mason and Wheeler 270 were able to 

 inactivate Microcystis extracts partially by heating with acid or alkali. 

 Steyn 260 clamied that growing algae are poisonous, that they discharge 

 their poisons into the water when they die, that the decomposition of 



