Three of these solvents have been shown to generate ROS in studies carried out in vitro on granular cell cultures from rat cerebellum. We assessed (OH)-O-center dot production by quantifying the rate of formation of 3,4-dihydroxybenzoic acid using a trapping agent, 4-hydroxybenzoic acid, infused via the microdialysis probe, into the prefrontal cortex of rats exposed intraperitoneally to the solvents. Extracellular MDA was quantified in microdialysates collected from the prefrontal
cortex of rats exposed, 6 h/day for ten days, to 1000 ppm of the solvents (except for n-butylbenzene, generated at 830 ppm) in inhalation chambers. Tissue levels of free and total MDA were measured in different brain structures for rats acutely (intraperitoneal route) and sub-acutely (inhalation) exposed to solvents. None of Z-DEVD-FMK cell line the six solvents studied increased the production of hydroxyl radicals in the prefrontal cortex after acute administration. Nor did they increase extracellular or tissue levels of MDA after 10 days’ inhalation exposure. On the other hand, a decrease in the concentrations of
free MDA in brain structures was observed after acute administration of n-hexane, 1,2,4-trimethylcyclohexane, toluene and n-butylbenzene. Therefore, data of this study carried out in vivo did not confirm observations made in vitro on cell cultures. (c) 2012 Elsevier Inc. All rights reserved.”
“Heat stress in Bos taurus
cattle is a problem that affects many regions of the world. Numerous studies selleck screening library have focused on heat stress in feedlots or environmental selleck chemicals llc chambers; but few have looked at undisturbed cattle on pasture. The present study followed two Bos taurus cattle breeds throughout a mid-Missouri summer to determine thermoregulatory responses to fluctuating summer air temperature (T-a), as well as differences in adaptation to heat Heat-sensitive Angus steers (ANG; n = 22; 480 +/- 7.15 kg BW), and heat-tolerant Romosinuano steers (RO; n = 11; 352 +/- 6 kg BW) were monitored on 12 day from June through August of 2009 in an endophyte free tall fescue pasture. Data were grouped into two, six-day periods representing peak (Period 1) and late (Period 2) summer for determination of adaptation. Respiration rate (RR) was measured via flank counting and telemetric temperature transmitters in the rumen of each animal monitored core temperature (T-rum). Romosinuano sustained a lower (P < 0.05) RR and T-rum compared to ANG during both periods. Linear relationships for RR and T-rum, compared against T-a for both Periods were determined. Slopes of RR to T-a from Period 1 to Period 2 decreased (P < 0.05) from 2.63 to 1.08 bpm/degrees C and 2.25 to 0.49 bpm/degrees C for ANG and RO, respectively. Slopes of T-rum to T-a also decreased (P < 0.05) from Periods 1 to 2 from 0.12 to 0.