| Popis: |
1. 1. Seasonal changes in total mass, weights of water, lipids and protein, and percentage lipids in brown adipose tissue of Tamiasciurus hudsonicus bear an inverse relationship to seasonal changes in temperature. 2. 2. Intracellular lipid distribution is unilocular and multilocular in summer and winter specimens respectively. 3. 3. DNA content of the tissue increases threefold from May to July, and thenceforth decreases progressively until the following spring. 4. 4. It is hypothesized that increased DNA content in the early summer represents proliferation of reticuloendothelial progenitor cells, which differentiate into functional brown adipose cells in early winter in response to increased thermogenic requirements of the organism. |
