What Causes Mineralization?

First Clown: "How can that be, unless..."

Second Clown: "Why, tis found so."
Hamlet

What happens in the equine cannon as our horse motors down the track? The blog previously "found" there are temporary increases in bone glue proteins and compaction of the mineral lattice and that both "effects" serve to create denser, stronger bone. And, may I add, these findings were other than pulling rabbits out of the hat. These temporary effects may be increased by timely subsequent speed work done within 8 days of the initial speed work with an ideal spacing of every 4 days.

Then there was this fellow
where it was speculated, possibly incorrectly, that mineralization of bone, being how it has developed over eons, would be little changed because we have suddenly decided to race horses. I was thinking of bone crystalization as a longer term process than a couple of weeks, and thus "timing" of speed work would fail to affect the size, shape, composition or density of the crystal. That was before being side tracked by Planck.


After the Planck article we reconsider our old friend the collagen molecule:
the worm like structure above consisting of water(white), Type 1 bone collagen, and HA mineral crystals (blue). Where is the collagen? Above the HA crystals have already subsumed most of it. These are aged fibrils instead of newborns. What was collagen is now the blue HA crystals.

Which is stronger D or E? After Planck we know E with higher mineral density than D.

And, we now know this interior mineralization grows simultaneously with exterior mineral coatings in similar spacing patterns. And so, if mineralization is found to be good, what causes it? Diet, exercise, genetics, cell electro chemistry, or possibly merely the horse racing gods?

To answer, a little chemistry is necessary.

calcium + phosphorus = hydroxyapetite crystals, i.e. HA crystals (the blue above)

HA crystals formation is initially promoted by osteoblasts, or are they? The research (seems to) state the exact process of crystal formation is "poorly understood", "unknown" "don't know" and other variations of the same thought, observations (similar to those in this blog) where such uncertainty hardly prevents each researcher from forwarding an opinion.

For normal calcification, best I can decipher, triggers start the process which seem to be mostly chemical, as opposed to electrical, or genetic, or exercise related, primarily involving a protein "alkaline phosphotase" (phosphorus), which in turn is stimulated by even smaller proteins whose names we'll avoid. It's what causes the unnamed (here) smaller proteins that is poorly understood with some claiming they result from genetic encoding, others from correct diet and so on. In the famous words of Professor Brian Fagan, "we don't really know."

Let's leave it like this: in bone, inhibitors and catalysts balance and control the chemical processes of mineralization. Put two chemicals together, you get a balanced reaction that results in crystals of a given size and spacial distribution in correct ratios.

Then there's the question whether these chemical reactions are local or systemic, i.e. must calcium and phosphorus be present in correct ratios in the horse's entire body, or just locally at the site of the mineralization. The latest seems to be that the required triggers need be "local."

But, there's so much more. These crystals within the collagen fibrils and on the outside coating will grow in certain ways. They refer to these in a multiplicity of (seemingly highly) relevant ways:
orientation--parallel, perpendicular, diffuse no preferred orientation
size, shape, alignment, tilt, thickness(me, bonding!)
increased molecular spacing/ packing order
thinner less well aligned crystals

One paper I read attributes the possibility of "electro chemistry" determining these qualities, but, then, something new from Hansma possibly extraordinarily important. For reasons unknown to me Hansma has suddenly decided to exercise mice on a tread mill. The little fellows were run on tread mills for 30 minutes a day for months. And, never mind that thereafter they decided to "sacrifice" the little critters, something perhaps of interest to PETA, the results were to find a relation between this exercise and the mineral quality of the bone. Discuss, next post.

Training:
Mon. 2/1: Off. Lazy. The trainer, instead of the horses.
Tues. 2/2: It begins. Perfect ground conditions for pasture romping. Horses into it with a lot of volume. Each horse was ridden 5 min. at the walk.
Wed. 2/3: Pasture romp #2. As expected more lazy and slower than yesterday. Each horse again ridden 5 min. at the walk.