A man underwent a surgery for acute abdomen. His urine is brown, with indican levels over 93 mmol per 24 hours. What can be estimated based on urine indican levels?

Answer options

1. Protein putrefaction rate in intestine
2. Ammonia neutralization rate
3. Oxidative deamination rate in aromatic amino acids
4. Decreased activity of ornithine cycle enzymes
5. Renal filtration ability