Gordon S. Born

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.

Placental Transfer and Teratology of Pentachlorophenol in Rats

Pentachloro[U-14C]phenol was administered orally to Charles River CD strain pregnant rats on day 15 of gestation. Concentrations found in the placentas and fetuses up to 32 hr remained very small indicating that the amount that passes through the placental barrier is negligible. Unlabeled compound was administered on days 8, 9, 10, 11, 12, and 13 of gestation. The incidence of resorptions in the treated animals was not significantly greater than that in the controls. Although malformations were observed, the number was minimal and could have been due to the toxic effects of the compound on the maternal rat.

The maternal distribution and placental transfer of cadmium in zinc deficient rats.

SummaryAlthough a transitory maternal zinc deficiency has been shown to result in an increased cadmium-induced fetotoxicity, the results of the present investigation indicated that a maternal zinc deficiency apparently did not affect the placental transfer of cadmium. However, a zinc deficiency did alter the maternal distribution of cadmium. The increased cadmium fetotoxicity associated with a maternal zinc deficiency may be caused by a maternal alteration rather than a direct effect on the fetus. Further study is necessary prior to any definitive statement concerning the effects of a maternal zinc deficiency on cadmium. fetotoxicity.

Potentiation of evoked adrenal catecholamine release by cyanide: Possible role of calcium

The effect of cyanide on release of catecholamines was evaluated in isolated bovine adrenal glands stimulated with 4 different agonists. Cyanide (0.1-1 mM) increased catecholamine release induced by barium or cadmium 2-3-fold. Acetylcholine or potassium induced secretion of adrenal catecholamines was also enhanced by cyanide, but only to the extent of 30-50%. These data suggest that cyanide acts by multiple mechanisms to enhance evoked catecholamine release. The above results may be partly explained by the fact that cyanide inhibited 45Ca efflux from stimulated bovine adrenals. Changes in plasma membrane permeability may be crucial in the alterations of ion flux and evoked catecholamine release caused by cyanide.

Thin-layer chromatography of DDT and some related compounds on aluminum oxide chromatoplates

Abstract The chromatographic behavior of DDT and fourteen related compounds, metabolites, analogs, and degradation products on commercially available pre-coated aluminum oxide thin-layer chromatoplates was investigated using thirty-three solvent systems. The color and/or fluorescence response of the DDT-type compounds and their sensitivity to a chromogenic reagent consisting of ammoniacal silver nitrate and 2-phenoxyethanol in acetone is discussed. A total of eleven compounds of the mixture were separated by two-dimensional thin-layer chromatography on aluminum oxide plates.

Differences in uptake of cadmium in selected organs of normal and alloxan-diabetic rats☆

The uptake of 109Cd in normal and alloxan-diabetic tissues (blood, liver, kidney, pancreas, and spleen) was studied. Cadmium concentration in normal tissues, except pancreas, reached a steady state after 8 hr, whereas in alloxan-diabetic tissues, the concentration was significantly dependent on the time interval. Cadmium concentration was higher in alloxan-diabetic blood than in the blood of nondiabetic controls. Spleen uptake was higher in alloxan-diabetic tissues during the first 24 hr but not significantly different after 240 hr. Cadmium concentration was higher in alloxan-diabetic livers during the first 24 hr but was lower after 240 hr. Cadmium accumulation in kidneys was the reverse of that in liver. Pancreas uptake was lower in alloxan-diabetic tissues during the first 24 hr but not statistically different after 240 hr. It is postulated that the differences in the distribution of cadmium in control versus alloxan-diabetic rats are due mainly to diabetes, which develops due to insulin deficiency and which introduces changes in the amount of biomolecules that bind cadmium as well as in the bond strength of cadmium to the different binding sites.

Effect of altered thyroid states on chromium uptake in rat blood.

Abnormal thyroid states hypothyroidism and hyperthyroidism, alter metabolic processes such as protein synthesis. The effects of hypo- and hyperthyroidism on metal and mineral metabolism have been reported by several investigators. These effects may be due to changes in protein levels or some other effect of thyroxine on the body. A change in the uptake, transportation, or rate of removal of a metal in the body could significantly affect metabolic processes. These effects could lead to toxicity resulting from either excesive or deficient amounts of the metal. This paper reports an investigation of the retention of trivalent /sup 51/Cr in the blood of rats having experimentally altered thyroid states.

Improved extraction procedure for 2,3,5-triiodobenzoic acid from milk and milk products

Whs s tudys 2 , 3 , 5 t r s 1 6 3 a c i d (TIBA) r e s t d u e s i n mi lk and mi lk p r o d u c t s u s ing sas chromatography 87 i t became n e c e s s a r y t o deve lop an e x t r a c t i o n and c l e a n u p p r o c e d u r e whs would c o n c e n t r a t e TIBA a n d / o r 8 m e t a b o l s s e p a r a t e Che compound from i n t e r f e r • n g mi lk c o n s t i t u e n t s , and g i v e a low backSround s i g n a l . Th i s was n e c e s s s s i n c e most e x t r a c t s solvents were round fo form emulsions w 8 milk or milk products ( e t h e r , me thano l , eChanol , i s o p r o p y l a l c o h o l , and aqueous fo rmic acld) or were expenslve (acetonitr 8 The earlier extraction method as used by L i sk (1) does noC i n c l u d e a c l e a n u p p r o c e d u r e . P,,rocedure s C l ean -up and E x t r a c t i o n P r o c e d u r e . M 8 o r mi lk p r o d u c t s ~ p l e s we 8 100 g. were p l a c e d i n a t a r e d 500 ml. e r l en m ey e r f l a s k on a magne t 8 s t i r r e r and t i t r a t e d dropwise w i th ~ P O 4 (85~-N.u untll the mixCure was at a pli of 2.5-3.0 (about 4 ml. per I00 S. samp1e). A minimum of 250 ml. of technlcal stade a c e t o n e was added and che m i x t u r e a l lowed to s t s f o r 60 m i n u t e s . The r e s u l t 8 s l u r r y was s e c c l e d i n an i c e b a t h f o r about 1 hour ( speeds f i l t r a t i o n ) and t hen f i l c e r e d w 8 vacuum on a 150 C s c i n t e r e d g l a s s f u n n e l . Acetone was e v a p o r a t e d from che f i l t e r e d

Effect of altered thyroid states on liver and kidney uptake of 109Cd in rats

Abstract Hypothyroid and hyperthyroid states were induced in rats by drug treatment with propylthiouracil and thyroxine, respectively. The thyroid states were verified by measuring serum thyroxine using a commercial competitive protein-binding technique. A single 109 Cd ip injection was then given to three groups: hypo-, eu-, and hyperthyroid. The uptake of 109 Cd in liver and kidneys was measured at times ranging from 1 to 120 hr. On a per gram basis, 109 Cd uptake in livers and kidneys of hypothyroid rats was significantly greater than that of eu- and hyperthyroid rats, even though there was a dwarfing effect in the hypothyroid group. The transfer of 109 Cd from the liver to the kidneys was not affected by the altered thyroid states.

Microwave Dosimetry Using Electrochemical Effects

ABSTRACTThe development of a self-contained microwave device for measuring energy density is described. This device, which measured 3 cm χ 3.5 cm χ 5 cm and weighed 17.7 g, received 2450 MHz microwave frequency current using a 0.12k (1.5 cm) dipole antenna. The microwave frequency current was rectified by Schottky barrier diodes and was integrated, over time, by an electrochemical plating cell. The selection of electrical components and studies to determine the device’s response to microwave radiation from 5 to 50 mW/cm2 are discussed and several recommendations for further studies are listed.