taiwan said:
Read much of this report on the drug and can't really find an indication of it's effect on patients with healthy rbc levels. It does say "the protein normalised hct levels without causing ethrythrocytosis" but I can't find the details of that claim.
Anyway, to say that on it's own or in synergy with EPO, it won't raise hct to a high normal level in a way that would be useful for an athlete - it's a reach. Particularly under the 50% rule. Noone's talking about jacking up to 90s levels.
That's because it was done on mice, unless you are referring to WT mice as healthy patients, which I'll do my conclusions.
From the article:
Conversely, treatment with rGas6 stimulates hematocrit recoveries and protects WT mice against the development of anemia, induced by hemolysis or in part by blood loss
Stimulates recoveries, not overproduction. That's why I think it's perfectly reasonable to suggest it could be used as a recovery aid.
In fact, the article does not go into much detail about the effect of Gas6 in WT mice, suggesting they didn't find much.
Figure 3 shows the Axl + rGas6 mutant returning to natural hematocrit at a similar rate to the WT, but they have not included WT +rGas6.
Figure 8 shows a similar response between EPO only and EPO+Gas6 in the WT (+/+)mouse.
Figure 10 shows Gas6 treated WT mice have a slightly higher hematocrit baseline and a much quicker return, which is why it's reasonable to draw the conclusion it could be used to aid recovery.
In an EPO non-responder Gas6 + EPO is worse at increasing hematocrit than EPO only in WT, meaning if Froome were an EPO non-responder and he was being treated with Gas6+EPO, he would probably need significantly higher doses of EPO to match a "healthy" doper.
This conversation is getting messy talking to two people, mainly for me trying to keep the two threads separate!
So, in conclusion, and this is all based on one study in mice, which is kind of important;
if Froome were a non-responder to EPO, treatment with Gas6+EPO would have less effect than treating an EPO-responder with EPO only.
The research seems to show little to no benefit in combination treatment of Gas6 and EPO for healthy individuals. The lack of much information on this also indicates these findings.
Gas6 treatment aids recovery of hematocrit in both healthy and EPO non-responders, but this recovery is back to baseline. So it has a possible use as a recovery aid.
You mention slight increases. Do we know how much of an increase is required for a perfrmance gain? 1% hematocrit relates to 1% improvement? I'm guessing it isn't that simple. And what is the spread of hematocrit percentages across the normal population? Do they vary by 10%, 20%, 30% etc. (at normal times, not within a GT).