Gestational diabetes mellitus (GDM) and preeclampsia (PE) are diseases developed during pregnancy. Late complications of gestational diabetes are diabetes mellitus, hypertension and cardiovascular diseases. Preeclampsia has a leading role in birth complications and is a leading cause of death by birth. Both diseases are characterized by insulin resistance. It became known recently that insulin stimulates the arginine uptake of the human umbilical vein.
Arginine does not only have a role in creating protein, but is also a precursor for blood-pressure decreasing NO and polyamids necessary for cell division and growth. Insufficient arginine supply can lead to pathomechanism of GDM and PE, which is why it is important to study the arginine transport of the placenta. The AMP-activated kinase (AMPK) stimulates the arginine transport of the placenta, and also reduces insulin resistance.
We have studied the arginine transport of both healthy and pathological placentas and whether there are changes in AMPK activity in placentas. My subtask during the research was to study arginine transport. We modeled the effects of insulin by pre-incubating the placenta tissue with insulin. We have measured arginine transport by light scattering and rapid filtration techniques, using placental microsomes and kaveola. AMPK activitiy in placental homogenate was examined by Western blot.
Our measurement results show that the rapid filtration technique is the most effective way to study the arginine transport of the placenta. A 60-minute insulin treatment does not significantly alter the speed of arginine transport. Compared to healthy samples, we have observed a 14% decrease in arginine transport by the samples with gestatios diabetes and preeclampsia. Our results suggest that by pregnancies with gestational diabetes or preeclamsia insufficient AMPK activity of the placenta can be observed.