Effect of carnitine administration on levels of lipid peroxides and activities of superoxide dismutase and catalase in isoproterenol-induced myocardial infarction in rats

The effect of carnitine administration on levels of lipid peroxide and activities of superoxide dismutase and catalase was studied in rats administered isoproterenol to induce myocardial infarction. Levels of fatty acid were lower in rats pretreated with carnitine at the peak period and given isoproterenol than the levels in isoproterenoltreated control rats. Lipid peroxides were decreased in the heart at peak infarction in carnitine-treated rats compared to the levels in isoproterenol-treated controls. Activities of superoxide dismutase and catalase showed no change in carnitine-treated animals given isoproterenol compared to those in normal control rats, while they decreased in animals treated with isoproterenol alone.     

Host Plant Use by the Invasive Halyomorpha halys (St?l) on Woody Ornamental Trees and Shrubs

The brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive plant-feeding insect native to eastern Asia. This herbivore is highly polyphagous, feeding on and damaging diverse plants, including field crops, vegetables, tree fruits, and ornamentals. Woody ornamental plants provide early- and late-season resources for adults emerging from and returning to overwintering sites, as well as feeding and breeding sites for H. halys throughout the growing season. In this study, we quantify the use of diverse plants by H. halys in two commercial nurseries in Maryland, recording data on the abundance of egg masses, early and late instar nymphs, and adults over a three-year study period. Our specific goals were to provide a quantitative comparison of the use of diverse plant species and cultivated varieties, identify non-hosts that could be used to create landscapes refractory to H. halys, and determine whether the use of plants varied across life stages of H. halys or the taxonomic status of plants. We found broad use of diverse plants in this study, identifying 88 host plants used by all life stages of H. halys. We also highlight the 43 plant taxa that did not support any life stage of H. halys and are thus classified as non-hosts. Interestingly, some of these plants were congeners of highly-used plants, underscoring high intrageneric and intraspecific variation in the use of plants by this polyphagous herbivore. We discuss how the selective planting of non-hosts, especially gymnosperms, may aid in reducing the agricultural and nuisance pest status of this invasive insect.     

RNA polymerase I and II activities in different brain regions of young, adult, and old rats

The activities of RNA polymerase I and II were assayed in nuclei isolated from different regions (cerebral cortex, cerebellum, hypothalamus, hippocampus, corpus striatum and pituitary) of brains from young (10 days), adult (6 months), and old (2 years) rats. The RNA polymerases I and II activities generally increased during maturation, i.e., from 10 days to 6 months of postnatal age and then showed a decrease from 6 months to 2 years of age in all the regions except in cerebral cortex where the RNA polymerase II activity was highest at 10 days but showed a gradual decrease through the lifespan up to 2 years.     

Corticosterone administration and lipid metabolism in brain regions during development.

Effect of corticosterone on lipid contents of different brain regions and the effect of age on the sensitivity of these regions to corticosterone have been studied. Corticosterone administration (40 mg/kg body wt, sc) to 17-day-old rat for 3 days led to significant decrease in phospholipid content of cerebellum and increase in cholesterol contents of hippocampus and striatum. However, there was no effect on cerebral cortex and brain stem lipids. This alteration in lipids was associated with decrease in [U-14C] glucose incorporation into cholesterol and phospholipids, decrease in plasma beta-hydroxy butyrate levels and increase in beta-hydroxy butyrate dehydrogenase activity in hippocampus and striatum, thereby suggesting that suppression of glucose utilization by corticosterone was compensated by higher utilization of ketone bodies for lipid synthesis in these regions. The sensitivity to corticosterone appears to be age-specific as, at 20-day, cerebellum, hippocampus and striatum were susceptible, at 10-day only hippocampus and at 40- and 90-day none of these regions responded to the treatment.