Catecholamines,ATP and dopamine-β-hydroxylase in the adrenal medulla of the hedgehog in the prehibernating state and during hibernation

The adrenal medulla of the hedgehog (E. europaeus L.) was studied by electron microscopy and biochemical methods for a characterization of the seasonal changes in the cells and subcellular organelles responsible for catecholamine (CA) storage.In the prehibernating state noradrenaline accounted for about 25% of the total CA; these glands contained a number of cells with small, electron-dense cored vesicles not seen in hibernation when adrenalin was the only detectable amine.Upon entrance into hibernation the hedgehog adrenal medulla increased in total CA, ATP, and dopamine-β-hydroxylase (DBH) concomitant with a decline in weight of the medulla.In hibernation the adrenomedullary cells contained granules with cores of moderate electron density. However, most of the cytoplasmic space was occupied by lipid droplets and large, membrane-enclosed follicles. These were disrupted by homogenization concomitant with a relative increase in particle-free, soluble DBH activity.The present findings indicate that the hedgehog stores a reserve of soluble DBH within the adrenomedullary cells during hibernation, thereby appearing well prepared for a rapid switching-on of adrenomedullary CA synthesis upon arousal from hypothermia.