Question about Alkaline Phosphatase

[stu07]

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Hey anyone,

What is the purpose of alkaline phosphatase once it's released by osteoblast during bone mineralization?

 

[SeventhSon]

i thought alk phos was used by osteoclasts for bone resorption...

at any rate, it's probably just background enzyme circulating in serum that has no point after normal cell turnover

 

[agranulocytosis]

I'm not completely sure about this, but since osteoblastic activity is associated with high levels of alkaline phosphatase and osteoclastic acitivity with acid phosphatase activity, I would think that bone mineralization needs an alkaline pH in order to proceed and bone resorption would need an acidic pH.

And an additional question I would like to pose to my peers:

In prostate cancer, are the high levels of alkaline phosphatase due to the release of prostatic alkaline phosphatase or the osteoblastic lesions from metastasis to the the bone? Or a combination of both??

 

[InternationlDoc]

alkaline phosphate is released by osteoblasts that then dephosphorylates pyrophosphate which normally inhibits bone mineralization.

rmr the Vit D stimulates its release

to agranulo: I believe it is related to metastasis more than prostatic

 

[DragonWell]

....

And an additional question I would like to pose to my peers:

In prostate cancer, are the high levels of alkaline phosphatase due to the release of prostatic alkaline phosphatase or the osteoblastic lesions from metastasis to the the bone? Or a combination of both??

Aren't prostatic secretions actually high in acid phosphatase, or am I drunk again? The majority of alkaline phosphatase is found in the bone and liver, where as mentioned above, it "catalyzes hydrolysis of organic phosphate esters at alkaline pH".

My understanding was that the increase in alk phos in prostate cancer mets was directly due to the osteoblastic nature of the lesions.

 

[bgreet]

I'm not completely sure about this, but since osteoblastic activity is associated with high levels of alkaline phosphatase and osteoclastic acitivity with acid phosphatase activity, I would think that bone mineralization needs an alkaline pH in order to proceed and bone resorption would need an acidic pH.

And an additional question I would like to pose to my peers:

In prostate cancer, are the high levels of alkaline phosphatase due to the release of prostatic alkaline phosphatase or the osteoblastic lesions from metastasis to the the bone? Or a combination of both??

Prostate cancer's #1 metastatic location is bone (sacral region, femoral head, and hip), and alkaline phosphatase (released from bone) in the presence of prostate cancer is usually an indicator of bone metastasis.

 

[agranulocytosis]

Aren't prostatic secretions actually high in acid phosphatase, or am I drunk again? The majority of alkaline phosphatase is found in the bone and liver, where as mentioned above, it "catalyzes hydrolysis of organic phosphate esters at alkaline pH".

My understanding was that the increase in alk phos in prostate cancer mets was directly due to the osteoblastic nature of the lesions.

Ahh, I think I was the one who was a little too drunk. You're right, prostatic secretions are high in acid phosphatase. I think that's why I was confused. As I was reading RR Path it said that alkaline phosphatase was a marker for bone mets in the carcinoma, and I just so happened to remember something about a certain phosphatase being in the prostate. Which phosphatase, of course, can make a HUGE difference.

 

[soon2Bmd2005]

what happens to alk phos levels when you get multiple myeloma or breast cancer that gets to the bone?...these are osteoLYTIC lesions...some sources say alk phos increases, others say it's normal...what do you all think?

 

[78222]

Aren't prostatic secretions actually high in acid phosphatase, or am I drunk again? The majority of alkaline phosphatase is found in the bone and liver, where as mentioned above, it "catalyzes hydrolysis of organic phosphate esters at alkaline pH".

My understanding was that the increase in alk phos in prostate cancer mets was directly due to the osteoblastic nature of the lesions.

Not relevent to the OPs question but..

The movie your avatar comes from freaked me out