A simplified fluorimetric method for corticosterone estimation in rat serum, tissues and mitochondria.

A simplified procedure has been developed for the extraction and estimation of corticosterone from rat serum, tissues and mitochondria. The suitably diluted samples were treated with freshly prepared chloroform: methanol mixture (2:1, v/v) and then extracted directly with the chloroform. Almost quantitative recoveries (90% and above) were obtained with the present method, compared to poor recoveries (65-81%) and variable results obtained by earlier procedure. Quantification of corticosterone content in tissues, such as liver, brain and heart, and in the mitochondria indicated significant concentration of corticosterone in tissues and mitochondria, as compared to the serum. The presence of corticosterone in the mitochondria suggests that the hormone may play a role in regulation of mitochondrial gene expression and/or their turnover.