Neurofibromatosis and renovascular hypertension in children

Abstract

The effect of cholera enterotoxin on infant rabbit intestinal protein synthesis was studied by measuring incorporation of radioactive amino acid into protein. The tissue was very active in protein synthesis in vitro, when incubated under air in a simple buffer with a single amino acid. Incorporation could be enhanced by using enriched media and constant gassing with 95 per cent O2 5 per cent CO2. Amino acid incorporation by ileum was twice that for jejunum. Cholera toxin, whether added directly in vitro or fed per os to produce experimental cholera diarrhea, failed to alter protein synthesis studied in vitro. Parenteral inoculation of labeled amino acid into choleraic animals, however, resulted in increased specific activity of gut protein. Increased graining of muscularis and epithelial cells was noted in these animals by autoradiography. Increased in vivo protein synthesis by choleraic intestine without similar changes in vitro is consistent with increased delivery of labeled amino acid to the gut epithelium from the blood stream during cholera. This may be due to increased transcapillary permeability during cholera in the infant rabbit or possibly due to increased mucosal blood flow. Intestinal protein synthesis itself is not altered; however, increased synthesis of a specific mediator protein cannot be excluded.