The effect of cryo-storage on the beta 2-adrenoceptor density and responsiveness in intact human lymphocytes

This study evaluates the effect of cryo-storage on beta 2-adrenoceptor number and formation of adenosine 3':5'-cyclic monophosphate (cAMP) in intact human lymphocytes as a measure of the beta 2-adrenoceptor responsiveness. Cryo-storage at -196 degrees C up to 12 months caused no significant differences in the total number of beta 2-adrenoceptors implying that apparently no loss of beta 2-adrenoceptor-protein occurs. The maximal isoprenaline-stimulated cAMP generation, and the stimulation-induced number of cAMP-molecules min-1 beta 2-adrenoceptor were unaffected of short-term storage (1-14 days), but changed significantly after long-term storage (3-12 months). We can conclude that lymphocytes can be stored for months for later determination of beta-adrenoceptors. The cryo-storage method described in this paper are, however, only useful for measurements of very large changes in cAMP formation, and our results indicate that the method should be further modified in order to preserve the lymphocyte responsiveness after cryo-storage.