Changes in plasma glucose, insulin, glucagon, catecholamine, and glycogen contents in tissues during development of alloxan diabetes mellitus in rats

Alloxan monohydrate (ALX) was given to rats (20 mg/100 g body weight) and plasma glucose (PG), immunoreactive insulin (IRI), immunoreactive glucagon (IRG), and catecholamine (CA) as well as the glycogen (G) content in the liver, muscle, and kidneys were measured. Although whether hypoglycemia was present immediately after injection was not clear, the PG level increased, with a modest peak after 2 h. The PG levels in rats receiving food 6 h after ALX injection increased substantially after 1 h and continued to increase after 24 h. Although the IRI level increased slightly 10 min after the injection, low amounts were present for up to 24 h due to continued fasting. There was a rise in the IRG level at 10 min after injection, and then it decreased again slowly to a low level during fasting. No change was observed in the CA level. Hepatic G further decreased at 30 min after ALX injection and started to increase from 2 h to a peak level after 18 h. Almost no changes were noted in muscle tissues. The G content in the renal cortex remained almost unchanged, although it tended to decrease slightly after 8 h. When rats were fed 6 h after ALX injection, the IRI level rose slightly. Hepatic G at 6 h after feeding was nearly equal to that during feeding itself, but it then decreased rapidly. Muscular G became equal to that during feeding. Renal G showed a clear tendency to increase 6 h after feeding and became about four times that during periods when rats were fed ad lib. In conclusion, not only PG, IRI, and IRG, but also tissue G levels were shown to change markedly in the early stage of ALX induced diabetes. (C) 1997 Academic Press.