I recall in this podcast or podcast with David Sabatini that a washout period needed to show an improvement in immune function.
Two week washout
From my hearing of the podcast, they only tested immune function after a two week washout. So, it's not known if the immune function would have shown the same boost without a washout.
Optimum dose
Very interesting is that 5 mg once-per-week gave the best immune boost and least side effects of the 3 dosing strategies tried. The other two were 20 mg once-per-week and 1 mg daily.
Dog study - heart repair
In the dog study, there was one dog out of five in the high dose group, a Doberman, with incipient left ventricular failure per echogram. The high dose group received 0.1 mg/kg of rapa MWF for 10 weeks (the low dose group received 0.05 mg/kg). The ejection fraction of the Doberman improved 10% to normal, but six months after stopping the Rapa the incipient failure had returned (a genetically common problem with the Doberman breed).
0.1 mg/kg in dog study
The amount of Rapa given with no known side effects to the five dogs in the high dose group was 0.1 mg/kg. At human weight, a 60 kg subject in the high dose group would have had 6 mg MWF.
Peak and Trough for 6 mg MWF
We can calculate the peak and trough using 63 hr for the half life of Rapa in humans. The steady state peak with 48 hr dosing would by 6mg x 1/(1-f), where f is the fraction left after 48 hr. A half life calculator gives f = 0.5897 i.e. 0.5897 of the starting dose remains after 48 hr. Calculating: 1/(1-0.5897) = 2.44. 2.44 x 6 mg = 14.6 mg peak in steady state with 48 hr dosing and 14.6 - 6 mg = 8.62 mg trough in steady state with 48 hr dosing. 72 hr between doses on weekends would lower these a bit (but not much).
Wow--people frequently get some mouth sores when starting out at 5 mg once-a-week. Starting at 2 mg once-a-week and working up may reduce the likelihood of mouth sores. (It worked for me). I would expect 6 mg MWF to be problematic.
Peak and Trough for 5 mg once-per-week
5 mg once-per-week (168 hr dosing) gives f = 0.1574. 1/(1-0.1574) = 1.186. 1.186 x 5 mg = 5.93 mg peak in steady state with weekly dosing and 5.93 - 5 mg = 0.93 mg trough in steady state with weekly dosing.
TorC1 and TorC2 theory
A partial explanation for Rapa's life extension effect follows: The peak dose must somewhat inhibit TORC1, but TORC2 should not be inhibited. When the Rapa decays to a low enough trough between doses TORC2 will not be inhibited.
TORC1 is involved in all anabolic functions such as cell growth, construction of proteins and organelles, etc. If TORC1 were completely inhibited too long cells would waste away, but when TORC1 is inhibited just right, cells will switch to anabolic mode just long enough for cell "house keeping" such as autophagy to clean house improving the cell's health. Presumably intermittent fasting, exercise, and caloric restriction may have similar effects. Rapa inhibits TORC1 but not completely (else continuous dosing would be deadly).
Edited by RWhigham, 08 September 2018 - 08:34 PM.