Effect of long-term experimental hypodynamy on the adrenal glands of Japanese quails: an ultrastructural study

Abstract

The effect of experimental long - term hypodynamy on the structure of the adrenal glands of the Japanese quail (Coturnix coturnix japonica) was studied. Two days after hatching the quails were suspended in special shirts below the ceiling of a cage so their feet did not touch the floor. They could consume feed and water ad libitum. Animals of the same age, hatched at the same time, and fed the same diet were used as controls. Experimental animals were sacrificed after 14, 28, 42, 56 and 126 d of hypodynamy. Whole adrenal glands were fixed and routinely processed for transmission electron microscopy. The ultrastructure of adrenal tissue showed morphological changes in cortical and medullary – chromaffin cells. Lipid droplets accumulated in the cytoplasm of cortical cells and medullary cells exhibited marked cytoplasmic vacuolization. We assumed that the changes resulted in hypertrophy of the adrenal glands. Adrenal cells contained damaged mitochondria and dilated cisternae of the endoplasmic reticulum. The morphological changes described were considered reversible. It has been supposed that the long – term hypodynamy an adaptation of the organism to stress would occur. Our results show that Japanese quails are capable develop under conditions of prolonged simulated weightlessness.