Effect of different levels of gossypol on transaminase activity, on nonessential to essential amino acid ratio, and on iron and nitrogen retention in rats.

Metabolic experiments with rats fed rations containing varying levels of free gossypol (from 3 to 109 mg/100 g) showed that nitrogen retention was not affected by gossypol while iron absorption decreased as the levels of gossypol in the ration increased. This in turn resulted in lower hematocrit and hemoglobin values and lower levels of iron in the liver. The levels of glutamic-oxaloacetic and glutamic-pyruvic transaminases, an indication of liver necrosis, increased in blood serum and decreased in liver when gossypol was fed. The ratio of nonessential to essential amino acids in both serum and liver increased with increasing levels of gossypol in the diet showing that, in spite of an equalized available lysine intake, the cottonseed pigment was capable of binding this and/or other essential amino acids. In all cases, weight gain was adversely affected by the level of gossypol used.