Influence of a protein-free diet on survival and DNA following hemorrhagic shock and ischemia.

Rats were fed a protein-free diet until 20-30% of body weight was lost and then hemorrhagic shock or liver ischemia was induced. Alkaline sucrose gradients were used to analyze for breaks in DNA. Whereas reversible shock caused no DNA damage in five rats on the standard diet, DNA damage was found in ten animals subjected to severe shock. In contrast, ten rats on the protein-free diet had no significant DNA breakage even after severe shock. Diet also influenced postoperative survival; ten of 15 rats on the standard diet compared to ten of 12 on the protein-free diet survived for the 1 h postshock liver sample. To examine the biologic effect animals were subjected to hemorrhagic shock without laparotomy and liver biopsy. Three of 18 rats on the standard diet and 12 of 20 animals on the protein-free diet lived longer than 2 h (P less than .001). One rat on the standard diet and three on the protein-free diet survived for longer than 72 h. After 30 and 60 min of liver ischemia, rats on both diets showed similar breakage of DNA with repair following reperfusion. After 120 min of liver ischemia, there was similar DNA breakage for both diets; however, for rats on the standard diet there was no repair while there was DNA repair for rats on the protein-free diet.