Tuesday, November 6, 2012

New LSJL and IGF-2 related study by Zhang and Yokota

Lengthening of mouse hind limbs with local administration of insulin-like growth factor 2

"C57/BL/6 mice (∼ 8 weeks old) were used in this study, and the mice were separated into two groups: an IGF2-treated group and a placebo group. In the IGF2-treated group, IGF2 was locally administered into the distal epiphysis of the left femur, and the right femur was used as a contralateral control. In the placebo group, saline was administered to the left femur as a vehicle control. The left and right tibiae, without any direct intervention, were employed as negative controls. The dosage of IGF2 was 100 μg/kg/day for 5 consecutive days, and bone samples were harvested on Day 14. Microcomputed tomography images did not show any anomaly at the IGF2 or saline injection sites.
In comparison with the vehicle control as well as the contralateral control, the results revealed that IGF2 significantly lengthened the treated femur, with an elevation of bone mineral density (BMD) as well as bone mineral content (BMC). The increase in the femoral length of the IGF2-treated left limb was 1.6% (p < 0.05) to the vehicle control, and 1.7% (p < 0.05) to the contralateral control. However, the length, BMD, and BMC of the tibiae were not affected by administration of IGF2 or saline. Western blotting analysis demonstrated that this administration of IGF2 upregulated phosphorylation of an extracellular signal-regulated kinase in the treated femur."

LSJL knee loading was actually more effective than IGF2 lengthening both the tibia and femur and by a greater amount.  The fact that LSJL lengthened both is actually mentioned as a downside as they are developing this as a method to treat limb length discrepencies.  With LSJL there was an increase in the contralateral limb but only the local limb was increased with IGF2.

"IGF2 activates transforming growth factor beta (TGFb) and extracellular signal-regulated kinase (ERK) signaling"<-both of these are likely activated by LSJL as well.  An increase in ERK1/2-p was validated by this study.

"Both IGF1 and IGF2 bind to IGF receptor 1, but only IGF receptor 2 can be bound by IGF2 and not by IGF1. They are reported to be able to recruit primary osteoblastic cells, and regulate proliferation and differentiation of chondrocytes in the growth plate."

"a C28/I2 chondrocyte cell line that administration of IGF2 (5 hours at 10–100 ng/ml) activates TGFb signaling"

It would suck if they abondoned LSJL for IGF-2. Maybe someone other than me can email Ping Zhang and ask if the results of this study means that they're not researching their lateral joint loading method? And we still don't know if IGF2 results in adult height increase than an increase in height velocity.  The scientists allude to testing IGF2 on mature skeletons in the future.

Look at the growth plate in figure 2 C, you can see that the growth plate is open at the end at the computer screen's left whereas it is fused at the end of all other growth plates.  Therefore IGF-2 may have an anti-fusion effect.  Could this effect occur in the adult plate?  Unfortunately there are no before pictures.  The IGF2 bone is much more porous than the other bones.

The scientists state that 8 week old mice are equivalent to twelve year olds.


  1. i would email him whats his email?, and why are you so quick to make such assumption:" ask if the results of this study means that they're not researching their lateral joint loading method" why would that study on igf2 mean anything to do with quiting lsjl?, i dont see the connection.

  2. i'll email him too. what is it?

    What I would want to see is if they can test the compression machine on an older creature and another animal, most specifically something closer to a human. Rat growth plates are already proven to be quite different than rabbit growth plates. Why not try to get baboons or chimpanzees? If the loading is done right it shouldn't hurt them.

    Maybe I am wishing for too much.

    1. pizhang@iupui.edu is the email for Ping Zhang.

      The study on IGF2 is better for limb length discrepancies as it only lengthens the target bone. Ping Zhang is in pediatrics so he may view IGF2 as better for his purposes.

      The problem with loading on other species is that they'd have to build a new loading device. They have to be able to standardize the results and they can't do that with say dumbells. But please ask.

      And I've found that the first question from an individual is more likely to be answered and since this is an important question that's why I'm asking for a first time questioner.

  3. just got a reply back, said he will continue working on lsjl.

  4. he posted to me thinking i was tyler, but he said this:

    Hello there,

    This is Ping Zhang, I'm working on the project of LSJL.
    Tyler Davis, would you like send me more info for your work which related with LSJL?


    Ping Zhang, MD
    Indiana University School of Medicine

    1. Tyler did you send him your work???????????

  5. Tyler...through all of your research there must be a synergistic combination of supplements to increase height...have you thought of any possible protocols outside of LSJL that would accomplish this?