快猫短视频

DRUGS that block the action of a protective protein in the placenta could
help to stop HIV-positive mothers from passing the virus on to their unborn
children.

P-glycoprotein (P-gp) stops toxic chemicals鈥攊ncluding drugs鈥攆rom
passing through the placenta, and also helps to maintain the blood-brain
barrier. In cancer, P-gp can make tumour cells resistant to drugs by pumping
them out of the cells. Alfred Schinkel and his colleagues at the Netherlands
Cancer Institute in Amsterdam bred mice lacking the gene that codes for P-gp.
When the researchers administered the anti-HIV drug saquinavir to these mice
when they were pregnant, the fetuses got five to seven times as much of the drug
as normal.

Buoyed by this success, the team administered saquinavir to normal mice,
along with cancer drugs that are known to block the action of P-gp. The foetuses
of these mice showed the same increase in saquinavir uptake as those lacking the
P-gp genes.

Schinkel hopes that giving HIV-positive pregnant women saquinavir in
combination with drugs that block P-gp could substantially reduce the risk of
passing the virus to their children. 鈥淲e鈥檝e demonstrated that we can increase
the drug loading of the mouse embryos,鈥� he says. 鈥淣ow it鈥檚 up to the clinicians
to look at patients.鈥�

Increasing the amount of anti-HIV drugs that can be administered to a fetus
in utero would be an important advantage, according to David Back, a
pharmacologist at Liverpool University. But he advises caution in case there are
side effects. 鈥淭here鈥檚 a lot we need to know about what happens when we shut
this protein down.鈥�