<<
>>

Cells in the Inner Medulla Adapt to Interstitial Hyperosmolality by Accumulation of Organic Osmolytes

Cells in the inner medulla not only exist in a hypertonic envi­ronment, but also regulate cell volume during changes in ambient osmolality. These cells accomplish this by accumulat­ing organic osmolytes that maintain the intracellular osmotic pressure and prevent cell shrinkage without marked increases in the concentration of intracellular electrolytes.

These sub­stances include sorbitol, betaine, inositol, and glycero- phosphorylcholine. The intracellular concentrations of these Osmolytes vary with the diuretic state of the animal, increas­ing during periods of urine concentration, when the medul­lary interstitial osmolality is maximized, and decreasing during diuresis, when medullary interstitial osmolality decreases. Changes in the intracellular content of organic osmolytes in response to changes in ambient osmolality occur by parallel changes in either the production (sorbitol) or transmembrane transport (betaine) of the osmolytes.

<< | >>
Source: Cunningham J.G., Klein B.G.. Textbook of Veterinary Physiology. Elsevier Health Sciences,2007. — 720 ð.. 2007

More on the topic Cells in the Inner Medulla Adapt to Interstitial Hyperosmolality by Accumulation of Organic Osmolytes: