Differential scanning calorimetry and enzymic activity of rat liver microsomes in the presence and absence of delta1-tetrahydrocannabinol.

The thermal transitions of rat liver microsomes and isolated lipids were investigated by using differential scanning calorimetry. Endothermic transitions at approximately-5 degrees C and between approximately18 degrees and 40 degrees C were detected in the membranes and at approximately-10 degrees C and between approximately 10 degress and 20 degrees C in the extracted lipids. Interaction with delta1-tetrahydrocannabinol of microsomal membranes and of extracted lipids influences the thermotrophic behaviour as revealed by differential scanning calorimetry and eliminates the break in the Arrhenius plot of the enzymic activity of O-demethylase.