Does IGF-1 cross the Blood Brain Barrier?

[Lavinco]

Can anyone answer this?

Thanks

[ScotchGuard]

From what I know about IGF it's released by the liver and absorbed into the muscles through the IGF receptors. If no receptor then IGF isn't absorbed. Since IGF is in the blood I guess it could cross into the brain but there isn't any IGF receptors in the brain. I'm curious to see someone post a study.

[Lavinco]

I guess I really wanted to know if synthetic IGF-1 crosses the BBB. Anyone know?

I should also mention, just because something floats around in the blood, this does not always mean that it crosses the BBB. 100 years ago researchers injected dye and fed blue dye to lab animals. When the checked them later, they saw the all the organs turned blue except for the brain.

As the skull protects the brain from external damage, so does the blood brain barrier protect the internal damage to the brain.

To my understanding, certain chemicals get a free pass while others are completely blocked. This is why some supplements are garbage while others work great and can be toxic. Examples can be fat soluble vs. water soluble vitamins.

Or just slam 6 beers and you will feel the effects of chemicals crossing the BBB quickly.

Aspirin and caffeine is supposed to cross, and so does glucose. But some things just can't get to the brain.

I would really like to know if synthetic IGF-1 gets a free pass.

[ScotchGuard]

Did you get an answer to your question?

[gym_junki]

good question now I'm interested to find out.

[Lavinco]

Yes I did and Yes it does cross into the BBB. I read it on PubMED very recently but for the life of me, I can't find where the article is.

[Lavinco]

Here is one abstract:
http://www.ncbi.nlm.nih.gov/pubmed/17008777 <--- *admin* (Approved Link)

[adam784]

Insulin -like growth factor-1 (IGF-1) given peripherally has been found effective in clinical trials to slow down neuronal degeneration in some nervous system diseases. This raises the question of whether and how IGF-1 crosses the blood-brain barrier (BBB). In this report, we found that IGF-1 had a half-life of 4.5 min in blood, could remain intact for 20 min, and entered brain and spinal cord linearly. In the brain, IGF-1 had an influx rate of 0.4 μl/g·min after intravenous (iv) bolus injection as determined by multiple-time regression analysis. Intact radiolabeled IGF-1 was present in brain at 20 min after iv injection. Most of the injected IGF-1 entered the brain parenchyma instead of being entrapped in the cerebral vasculature. Addition of nonradiolabeled IGF-1 enhanced the influx of radiolabeled IGF-1 after iv injection, but inhibited the influx of radiolabeled IGF-1 by in-situ brain perfusion, suggesting that protein binding can explain the difference between the iv and perfusion experiments. In the spinal cord, the cervical region had the fastest uptake, followed by lumbar spinal cord. The thoracic spinal cord had the slowest uptake, comparable to that of brain. By contrast, des(1-3)IGF-1, an IGF-1 analogue with little protein binding but similar biological activity, had a shorter half-life in blood, slower influx rate into brain, and no alteration in pharmacokinetics after addition of nonradiolabeled peptide. We conclude that IGF-1 enters the CNS by a saturable transport system at the BBB, which functions in synchrony with IGF binding proteins in the periphery to regulate the availability of IGF-1 to the CNS.

http://content.karger.com/ProdukteDB...rtikelNr=54584<--- *admin* (Approved Link)

[ScotchGuard02]

Since IGF-1 is best injected locally maybe I should inject it directly into my brain. LOL Cool information.