The researchers evaluated the effects of long-term oral infusion of a Prostaglandin of E series 1 (PGE1) analogue on hepatic and whole-body nitrogen metabolism.
They reported their findings in the July issue of the Journal of Hepatology.
Some 10 patients with advanced cirrhosis were studied in paired experiments, before and 30 to 50 days after oral misoprostol therapy.
Alpha-amino-nitrogen levels and urea-nitrogen synthesis rate were measured in the post-absorptive state, and in response to continuous alanine infusion (2mmol/kg per hour, for 4.5 hours).
Data were used to compute the functional hepatic nitrogen clearance (i.e. the slope of the regression of alpha-amino-N levels to urea-N synthesis rate) and the apparent nitrogen exchange.
|Effects of misoprostol:|
- Reduced urea-N synthesis rate
- Increased hepatic nitrogen clearance
| Journal of Hepatology |
Misoprostol reduced urea-N synthesis rate (during fasting and in response to alanine), resulting in a positive nitrogen exchange.
The authors found that functional hepatic nitrogen clearance slightly increased.
In addition, the regression line was rightwards shifted, indicating a reduced urea synthesis rate at any alpha-amino-N concentration.
Amino acid- and ammonia-N did not accumulate in plasma.
Furthermore, no systematic effects on insulin and glucagon were observed.
Giampaolo Bianchi, of the University of Bologna, concluded on behalf of fellow colleagues, "Data are consistent with a nitrogen sparing mechanism of misoprostol, not mediated by hormone levels.
"These effects may be beneficial in clinical hepatology, and need to be tested in controlled trials."