Insulin-mediated post-transcriptional regulation of hepatic malic enzyme and albumin mRNAs.

Livers of insulin-treated diabetic rats accumulate albumin and malic enzyme mRNAs at very different rates. We now report that in normal rats insulin directs a specific increase in malic enzyme mRNA, while albumin mRNA levels remain unaltered. These studies support the contention that insulin regulates the accumulation of hepatic mRNAs in a highly specific manner.

Evaluation of a synthetic oligonucleotide probe for diagnosis of Plasmodium falciparum infections.

A radiolabeled synthetic oligonucleotide was evaluated as a diagnostic probe specific for Plasmodium falciparum using blood samples lysed directly on nitrocellulose filters. The probe technique successfully diagnosed malaria in experimentally infected chimpanzees that had 0.001% parasitemias (50 parasites/microliter) as determined by blood smears, and in 1 chimpanzee whose blood smear was negative, but whose blood was culture-positive for P.

Insulin mediates the asynchronous accumulation of hepatic albumin and malic enzyme messenger RNAs.

We have compared the rate of accumulation of hepatic albumin and malic enzyme mRNAs following insulin treatment of diabetic rats to determine whether insulin coordinately increases mRNA levels or specifically induces the accumulation of individuals mRNAs. Initially, the quantities of both albumin and malic enzyme mRNAs are reduced in diabetic rats compared to normal rats as determined by RNA blot analysis using complementary DNA probes. Following insulin administration for 12 h, albumin and malic enzyme mRNA levels increase at similar rates.

Insulin and fructose regulate malic enzyme activity by different processes.

A comparison of the regulatory processes controlling hepatic malic enzyme activity following treatment of diabetic rats with insulin or with a high fructose diet demonstrated several important differences. Insulin treatment caused a 50-fold increase in activity, due to a 12-fold increase in enzyme quantity and a 4-fold increase in specific activity(units/nmol). Dietary fructose caused a 3-fold increase in enzyme activity, due to a 3-fold increase in enzyme quantity, with no change in the specific activity of the enzyme.