Acute Homocystinuria Model in Primates

Example 10

The objective of this study was to develop an acute model of homocystinuria in nonhuman primates. Male cynomolgus monkeys of approximately 2-5 years of age (average weight of 3.4 kg) were fasted overnight and orally administered a methionine load at 100 or 300 mg/kg, and plasma was collected at 0-, 0.5-, 1-, 2-, 4-, 6-, and 24-hours post-dose for methionine and total homocysteine measurements by LC-MS/MS.

Oral administration of methionine (100 or 300 mg/kg) resulted in a dose-dependent increase in plasma methionine levels, with peak concentration recorded at 30 minutes and 1 hour post dose for 100 mg/kg and 300 mg/kg, respectively (FIG. 16A). Plasma methionine concentrations gradually decreased over time and reached pre-dose levels by 24 hours. The oral methionine load also resulted in a significant elevation in total plasma homocysteine by 30 minutes post dose, but no statistically significant difference between groups was noted (FIG. 16B). By 24 hours, total homocysteine levels had returned to baseline values for both groups. In conclusion, this study indicates that oral administration of a methionine load to nonhuman primates leads to acute homocystinuria.