Effects of pre- and postnatal cysteamine exposure on renal function in therat

The safety of cysteamine after renal transplantation and during pregnancy i s an important issue, since girls with cystinosis are in better health on c ysteamine therapy and thus more likely to become pregnant. In the first stu dy, cysteamine was given to pregnant rats on days 6.5-18.5 post conception in oral doses of 0, 37.5, 75, 100, and 150 mg/kg per day. The dams were sac rificed on day 20.5, the fetal kidneys removed and prepared for histologica l examination. In the second study, cysteamine was given to dams on days 6. 5-19.5 post conception in oral doses of 0, 37.5, 50, and 75 mg/kg per day. Darns were allowed to give birth naturally and pups were given cysteamine o n days 4-21 to yield the same oral doses of cysteamine given to the dam. Re nal function was evaluated on day 35. Histological examination of fetal kid neys revealed no changes even in kidneys fi om fetuses with growth retardat ion and malformations. Furthermore, there were no alterations in renal func tion in offspring on day 35. These findings demonstrate that cysteamine the rapy does not affect renal development in the rat. Further investigations w ill be required to prove whether cysteamine therapy has the potential to af fect renal development in the human.