Major Effect of various hormones on bone

[Guest guest]

Major Effect of various hormones on bone

http://www.uic.edu/classes/phyb/phyb402dbh/Calcium_homeostasis_files/slide0055_i\

mage007.jpg

Bone formation is stimulated by:

Growth hormone (constant)

Insulin-like growth factors

Insulin

Estrogen

Androgen

Vitamin D (mineralization)

Transforming growth factor - Beta

Skeletal growth factor

Bone-derived growth factor

Platelet-derived growth factor

Calcitonin

Parathyroid hormone (intermittent)

Bone formation is inhibited by:

Cortisol

Bone resorption is stimulated by:

Parathyroid hormone (constant)

Vitamin D [needed to make PTH..gw]

Cortisol

Thyroid hormone

Prostaglandins

Interleukin - 1

Interleukin - 6

Tumor necrosis factor - Alpha

Tumor necrosis factor - Beta

Bone resorption is inhibited by:

Estrogen

Androgen

Calcitonin

Transforming growth factor - Beta

y - Interferon

Nitric oxide [the arginine tie-in!..gw]

========================

To hold bone density constant we need to balance bone building osteoblast

activity to equal that of the bone destroying

osteoclasts and to increase density we need to boost osteoblast activity over

that of the osteoclasts.

When we get an increase in osteoblast activity over osteoclast, we will get a

net increase in the collagen matrix

(osteoid) availability and hence more matrix places to deposit calcium and

stronger bones.

While calcium homeostasis is an issue, it's actually more osteoblast activity,

more matrix / osteoid that is needed as

we age.

========================

Good Health & Long Life,

Greg ,

http://www.ozemail.com.au/~gowatson

gowatson@...