Ammonia
Revision as of 14:34, 22 July 2010 by Bara (talk | contribs) (Created page with ''''Ammonia''' is a by-product of protein degradation which is transported in the portal vein and metabolised to urea in the liver via the urea cycle. Ammonia is generated in n…')
Ammonia is a by-product of protein degradation which is transported in the portal vein and metabolised to urea in the liver via the urea cycle. Ammonia is generated in normal animals through the following physiological processes:
- Hepatic catabolism of body proteins and of proteins absorbed from the gut, including those obtained after gastro-intestinal haemorrhage.
- Metabolism of glutamine by enterocytes of the small intestine, the source of 25% of the energy used by these cells.
- Bacterial and intestinal degradation of urea by urease in the colon.
- Bacterial degradation of undigested amino acids in the colon.
In animals with PSS, ammonia is not removed from the portal blood as this bypasses the liver, leading to an increase in its blood concentration.