PEROXISOMAL CHANGES DURING HIBERNATION OF JERBOA (JACULUS-ORIENTALIS)

As a member of the order of Rodentia, jerboa (Jaculus orientalis) is a natural deep hibernator and lives in sub-desert highland in many part s of the world, including Morocco. Its small size (adult body weight s imilar to 100 g), availability in the wild, tolerance to laboratory co nditions, and some unique peroxisomal properties make it a suitable re search subject for exploring peroxisome biogenesis under prehibernatin g and hibernating states. During 3 wk, animals referred to as the preh ibernator group were exposed to cold temperature (5 to 7 degrees C) wi th food ad libitum. Part of the prehibernator group entered deep hiber nation 24 to 48 h after starvation. Animals were sacrificed 4 and 6 d after starting hibernation. As a control, a third group, consisting of active animals, was maintained at 22 degrees C. Concerning hibernatio n, results from plasma analysis showed an increased level for both ket onemia and ureamia, while triglyceredemia was decreased. Liver acyl-Co A oxidase activity, a peroxisomal beta-oxidation enzyme, increased dur ing hibernation. Liver peroxisomal urate oxidase was induced only duri ng the prehibernating state and remained at an increased level until t he fourth day of hibernation. The variations were concomitant to a dec rease in peroxisomal protein yield and a differential change in peroxi somal protein pattern in sodium dodecyl sulfate-polyacrylamide gel ele ctrophoresis during prehibernating or hibernating states. These prelim inary results showed that cold exposure and hibernation affect biogene sis of liver peroxisomes in jerboa.