Effects of toluene inhalation on brain biogenic amines in the rat.

The effects of toluene exposure on the biogenic amine concentrations in the central nervous system were investigated in the rat. Toluene was administered via inhalation to groups of rats at concentrations of 0, l00, 300, or 1000 ppm. After an 8-h continuous exposure, animals were sacrificed and whole brain concentrations of dopamine (DA), norepinephrine (NE), and 5-hydroxytryptamine (5-HT) were determined. The data indicated a significant increase in whole brain concentrations of DA following the 100-ppm exposure. A regional analysis of DA, NE, and 5-HT concentrations in rats exposed to 1000 ppm of toluene for 8-h indicated a significant increase in DA concentration in the striatum. A significant increase in NE concentrations was detected in the medulla and midbrain while 5-HT concentrations were significantly increase in the cerebellum, medulla, and striatum. The results indicate that toluene action results in elevated concentrations of behaviorally significant neuro-transmitters.

Stannous-ion quantitation in pyrophosphate and polyphosphate radiopharmaceutical kits using differential pulse polarography.

Stannous salts are used as reducing agents in many radiopharmaceutical kits. Differential pulse polarography, with 1 M sulfuric acid as the supporting electrolyte, is a relatively simple and effective technique for stannous quantitation and can be used in the quality assurance testing of pyrophosphate and polyphosphate radiopharmaceutical kits.

Absorption, distribution, and excretion of 14C-meglumine in rats and dogs after administration of 14C-meglumine salicylate.

Meglumine labeled with carbon-14 was administered orally as 14C-meglumine salicylate to rats and dogs to study its distribution and excretion. The compound was incompletely absorbed; that which was absorbed was rapidly excreted in the urine. Peak blood levels were about 5-10 mug/ml in rats and 2-8 mug/ml in dogs. Tissue levels were negligible at the end of the experimental periods. No evidence for N-demethylation or oxidation to carbon dioxide was obtained.

Synthesis of 14C-meglumine salicylate and its disposition in humans after oral administration.

The synthesis of 14C-meglumine salicylate was accomplished by heating 14C-meglumine with salicylic acid, in equimolar ratios, in 2-propanol. The average radiochemical yield was 97.5%. Ten healthy adult male volunteers were given 1.2 g of the compound orally. Five took 1.2 g of 1-deoxy-1-[14C]-methylamino-D-glucitol salicylate (containing about 47 micronCi), and five others took 1.2 g of 1-deoxy-1-methylamino-D-[U-14 micronCi), and five others took 1.2 g of 1-deoxy-1-methylamino-D-[U-14C]-glucitol salicylate (containing about 45 micronCi). Urine and feces were collected for 5 days, and blood was sampled for 24 hr. The peak urinary excretion of meglumine and/or its metabolites occurred between 4 and 8 hr after administration (about 7.2% of the administered dose). Meglumine was excreted primarily in the feces (72.4% over 5 days) and, to a smaller extent, in urine (21.3% over 5 days). No activity was detected in blood. The excretion rate and percentage excreted were the same for both groups of subjects, suggesting that meglumine was not metabolized by N-demethylation or conversion to carbon dioxide. The highest blood salicylate level, 44.4 +/- 1.9 microng/ml, was observed 1 hr after administration. Urinary levels of salicylic acid and its metabolites were observed to be at a maximum at 8 hr. Total salicylate recovery was 94.7 +/- 1.5% in 48 hr. Salicyluric acid was the major metabolite, accounting for 69.5 +/- 3.6% of the dose. Salicylic acid accounted for 6.8 +/- 1.2%.

A comparative study of iodine and potassium perchlorate metabolism in the laying hen. 2. Uptake, distribution, and excretion of potassium perchlorate.

The concentrations of 36Cl-labeled potassium perchlorate (K36CiO4) and previously reported iodide (131I) in the ova, thyroid gland, and blood of the laying hen were compared in this investigation. Radioperchlorate concentration and deposition properties showed a remarkable resemblance to those of iodide (131I). The topographic distribution of radioperchlorate in ova followed a peripheral and concentric ring deposition identical to that observed in the 131I investigation. The studies of the distribution of radioperchlorate showed that about 10.3, 2.0, and 1.4% of a single intramuscular injection of K36CiO4 was retained in the body at 3, 24, and 48 hours, respectively. The largest total concentration in the 3-hour group was found in the blood (2.9%), followed by muscles (2.4%), internal organs (1.1%), and the 10 largest ova (1.0%). The 24 and 48-hour hens' ova showed the largest concentrations with values of 1.5 and 1.2% of the dose, respectively. This represented 76.9 and 81.3% of the total activity retained in the body at these times. The excreta in the 3 and 24-hour experiments accounted for most of the radioperchlorate dose.

A comparative study of iodine and potassium perchlorate metabolism in the laying hen. 1. incorporation of I-131 in chicken ova.

The uptake of 131-I in chicken ova was studied for 3 hours after a single intramuscular dose. There was uptake as early as 10 minutes and it continued throughout the 3 hours in spite of a rapid decrease in blood activity. The fast growing ova, weightin 0.5 to 2.0 grams, were the most efficient in the uptake of 131-I per unit weight. Autoradiograms of the topographic distribution of 131-I showed a peripheral deposition. When multiple doses were given, concentric rings in the growing ovocytes were seen.

Radionuclide content of and 222Rn emanation from building materials made from phosphate industry waste products.

The radionuclide content and 222Rn emanation coefficients of selected construction materials were determined. The materials were analyzed for 226Ra, 228Ra and 40K by gamma-ray spectrometry. Mineral wool insulation, which is made from Tennessee phosphate slag, and commonly used insulation, which is made from blast furnace slag, had similar concentrations of these radionuclides. Concrete blocks made with phosphate slag had enhanced 226Ra and 228Ra contents when compared to ordinary concrete block. The mineral wool insulation materials which were examined had emanation coefficients that were a few (2-6) times 10(-3). All other materials had emanation coefficients that ranged from 6 X 10(-4) to 4 X 10(-2).

An intercomparison of whole-body counters at participating region III nuclear power plants.

Seventeen Region III nuclear stations originated and participated in an intercomparison study of their whole body counting procedures using the same calibration standard. The first phase of the study involved transporting a phantom containing four reactor-produced radionuclides and 40K to each plant. The plant staff were asked to follow all procedures applicable for a human subject including routine and investigative counts, if necessary, and to provide a printout of the results to the project investigators. The results from each plant were normalized for intercomparison by calculating the ratio of the reported activity to the actual activity after correcting for the appropriate amount of decay to the time of the count. Five plants reported 60Co values outside 1 standard deviation (SD) of the mean for 60Co and one plant did not detect the presence of 60Co. According to previously established procedures, these six plants were revisited after a period of time in which internal recalibration and corrective actions could be made. Four of the six plants had results which were still outside 1 SD of the mean for the original study. A final report in coded form to protect plant anonymity was provided to those stations to guide them in making further improvements, if they chose to do so.