Hormonal Control of Renal Phosphoenolpyruvate Carboxykinase Activity during Development of the Rat

Abstract

The effect of injections of hormones in utero on fetal rat kidney and liver extramitochondrial phosphoenolpyruvate carboxykinase activity has been studied. Glucagon and thyroxine induced the liver enzyme but none of the hormones tested affected the renal enzyme. In the postnatal rat, the hepatic phosphoenolpyruvate carboxykinase activity is increased after triamcinolone or thyroxine injection but only triamcinolone injection increases the activity of the kidney enzyme. It is suggested that the rise in renal phosphoenolpyruvate carboxykinase activity at about 10 days of age is due to the increase in blood corticosterone content occurring at the same age.

Hormonal Control of Glucose-6-phosphatase and Phosphoenolpyruvate Carboxykinase Activities in the Fetal Rat Kidney

“…The effect of triamcinolone on the renal PEPCK in fetal rat has been previously demonstrated by Mencher and Reshef (18); for these authors, the hormone induces an increase in the pre-existing enzyme activity but does not cause the primary appearance of PEPCK in kidney of fetuses. Hauser and Bailey (9) administrating triamcinolone into rat fetuses at a dose 25 times as high as that used in present experiments did not observe any increase of the PEPCK activity. Such a negative result is very likely due to a too short delay (5 hr) between injection and sacrifice, the time-course of the hormone effect being relatively slow (18).…”