[ruki]

Originally Posted by guaiac_boy

I am wondering about what you mean by this statement though:

Maintainence of blood bicarbonate is a primary function of the kidney/gill. It might be more correct to state that they regulate readsorption vs excretion, but for all practical purposes it results in the same thing - more bicarbonate in the blood.

I was taking the absolutist position that the kidneys regulate pH by choosing to dump or not dump something. They don't produce it, it's initially absorbed by the intestines. They get it from the blood and choose to release it or not. They can store it in intermediate forms to supply buffering capacity, but there is a limit to how much can be stored in the buffer.

As far as I know, skeletal catabolism isn't a primary mechanism for pH control. Osteoclasts will increase their adsorption of bone as a result of many stimuli, but most often this is in response to serum calcium levels, phosphate levels, or various endocrine disorders.

I'm not a medical person, but may have read too many articles which sometimes are oversimplifed to the point of being misleading. One of the frequently repeated health tips for osteoporosis is to not drink carbonated beverages since this will try to raise the pH of the body. If you do not consume enough high pH items, the body will dissolve bone to maintain equilibrium. The kidneys can not produce enough bicarbonate if you don't consume enough base materials and instead consume lots of carbonated beverages. Is this accurate or inaccurate?