Re: AGING: mammalian lifespan extension-IGF-1-colostrum-citations

From: Robert J. Bradbury (bradbury@aeiveos.com)
Date: Tue Jan 14 2003 - 08:56:32 MST


On Mon, 13 Jan 2003, Extropian Agro Forestry Ventures Inc. wrote:

> http://www.marysgarden.com/colostrum/growth_factors.htm
>
> Q-can oral colostrum IGF-1 survive digestion and successfully pass the gut?

IGF1 is a 155 amino acid protein, so I strongly doubt it can be absorbed
through the gut. For more on IGF1 see:

http://mutdb.org/AnnoSNP/data/N1/S0/RU/AC.nt.html

or Google on IGF1 or somatomedin C.

> can microencapsulation achieve the first hurdle?

It seems difficult, some work has been done on this with respect to insulin, see:
R. Narayani, "Oral delivery of Insulin - making needles needless"
Trends Biomater. Artif. Organs 15(1):12-16 (2001)
http://www.angelfire.com/sd/sbaoi/pdf/15-1-12-16.pdf
(anglefire requires you paste the URL into your browser).

IGF1 is probably harder than insulin since insulin only has 51 amino acids.
See: http://www.factmonster.com/ce6/sci/A0858846.html

> Can peyer's patch (sp)or other portion of gut snag this protein (pt2)?

A quick read suggests that intestinal M cells sample proteins in the
gut and transfer them to immune system cells in the Peyer's patch.
I suspect in that process they get diced up into the 8-12 amino acid
fragments that form the working basis for most immunity.

> otherwise other means to stimulate optimal levels are required...

Its downstream from Growth Hormone, so boosting GH level might have
the effect of boosting IGF1. *But* an IGF1R+/- mouse (that with the
extended lifespan) would effectively have *lower* IGF1 levels (less
IGF1 signal being received by the cells).

The p66shc gene mentioned by Joao seems to be one of the internal
signalling factors for the IGF1 receptor -- so the results are
consistent and seem to be acting via the same pathway.

Robert



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