Kondomerkos D J, Kalamidas S A, Kotoulas O B
Department of Anatomy, Histology and Embryology, Medical School, University of Ioannina, 45110 Ioannina, Greece.
Microsc Res Tech. 2004 Feb 1;63(2):87-93. doi: 10.1002/jemt.20000.
The effects of glucagon on the ultrastructural appearance and acid glucosidase activities in the liver and heart of newborn rats were studied. Liver or heart glycogen-hydrolyzing activity of acid glucosidase increased 3 hours after birth and gradually decreased from 3 to 9 hours. Maltose-hydrolyzing activity of acid glucosidase also rose 3 hours after birth, maintained a plateau between 3 and 6 hours, and fell at 9 hours. The administration of glucagon increased autophagic activity in the hepatocytes at the age of 6 hours. Glycogen inside the autophagic vacuoles was decreased, apparently due to the increased glycogen degradation. Glycogen-hydrolyzing activity was elevated in both the liver and the heart. Maltose-hydrolyzing activity was elevated in the liver, but not in the heart. The results of this study suggest that the glycogen-hydrolyzing and maltose-hydrolyzing activities of acid glucosidase are due to different enzymes. Glucagon's effect on the glycogen-hydrolyzing acid glucosidase activity and autophagosomal morphology is similar in both the liver and the heart.
研究了胰高血糖素对新生大鼠肝脏和心脏超微结构外观及酸性葡萄糖苷酶活性的影响。酸性葡萄糖苷酶的肝脏或心脏糖原水解活性在出生后3小时增加，并在3至9小时逐渐下降。酸性葡萄糖苷酶的麦芽糖水解活性在出生后3小时也升高，在3至6小时保持稳定，在9小时下降。给予胰高血糖素增加了6小时龄肝细胞的自噬活性。自噬泡内的糖原减少，显然是由于糖原降解增加。肝脏和心脏中的糖原水解活性均升高。肝脏中的麦芽糖水解活性升高，但心脏中未升高。本研究结果表明，酸性葡萄糖苷酶的糖原水解和麦芽糖水解活性是由不同的酶引起的。胰高血糖素对肝脏和心脏中糖原水解酸性葡萄糖苷酶活性和自噬体形态的影响相似。
