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1705. Depressant activity of 1,4-butanediol
PROCESSING AND PACKAGING CONTAMINANTS, THE CHEMICAL ENVIRONMENT
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PROCESSING A N D P A C K A G I N G C O N T A M I N A N T S 1705. Depressant activity of 1,4-butanediol Roth, R. H. & Giarman, N. J. (1968). Evidence that central nervous system depression by 1,4-butanediol is mediated through a metabolite, gamma-hydroxybutyrate. Biochem. Pharmac. 17, 735. The depressant activity on the central nervous system exerted by 1,4-butanediol (I) resembles that produced by 3,-butyrolactone and ~,-hydroxybutyric acid (II) but is slower in onset and more prolonged. Evidence has now been produced that II is the active metabolite responsible for the effect of I. Intravenous injections of 5.8 meq I/kg caused the appearance of II 1.5 hr later in the blood and brain of rats. The brain concentration of II correlated well with the apparent sleeping time following a dose of I. In animals given a prior injection of fl-hydroxybutyrate, a known antagonist of the depressant effect of II, the sleep induced by I was delayed and shortened and the brain concentration of II found 1.5 hr after the dose of I was significantly reduced. This finding supported the view that the central depressant effect of I depends upon its metabolic conversion to II.
T H E CHEMICAL E N V I R O N M E N T 1706. The cement hazard underlined
Geiser, J. D. (1968). Les facteurs de sensibilisation dans l'ecz~ma au ciment. Schweiz. reed. Wschr. 98, 1193. Cement eczema is reported as being the most common occupational dermatosis encountered in Switzerland and constituted 2.38 ~o of 53,139 cases of dermatosis and 16.2 Yo of 7794 cases of eczema (contact dermatitis) seen by this author during the period 19471966. Patch testing of those suffering from cement dermatitis showed an incidence of sensitivity to dichromate of 92.4 Yo and to cobalt of 38.3 Yo. Less commonly demonstrated sensitivities were to arsenate, iodide, nickel and metavanadate. The major factors determining the development of cement dermatitis were considered to be the degree of exposure, the alkalinity of the material and the presence of metallic ions, principally of chromium and cobalt. No other metal was believed to contribute materially to the dermatosis picture. [We have previously drawn attention to the role of chromium in inducing cement dermatitis (Cited in F.C.T. 1966, 4, 631) and to the sensitization potential of both nickel and cobalt present in the material (ibm 1966, 4, 544).] 1707. Effect of cyanide on amino-acid transport in brain slices Levi, G. & Amaducci, L. (1968). Effect of acute cyanide intoxication on the active transport of amino acids in brain slices. J. Neurochem. 15, 459. Although it is difficult to correlate results obtained in vitro and in vivo, the mechanisms of amino-acid transport are believed to be the same in brain slices as in living brain. This belief has led to the use of brain slices to postulate the effects of various compounds on amino-acid transport in the intact brain. In the present study, brain slices from rats exposed to cyanide vapour for a short time
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PROCESSING A N D P A C K A G I N G C O N T A M I N A N T S 1705. Depressant activity of 1,4-butanediol Roth, R. H. & Giarman, N. J. (1968). Evidence that central nervous system depression by 1,4-butanediol is mediated through a metabolite, gamma-hydroxybutyrate. Biochem. Pharmac. 17, 735. The depressant activity on the central nervous system exerted by 1,4-butanediol (I) resembles that produced by 3,-butyrolactone and ~,-hydroxybutyric acid (II) but is slower in onset and more prolonged. Evidence has now been produced that II is the active metabolite responsible for the effect of I. Intravenous injections of 5.8 meq I/kg caused the appearance of II 1.5 hr later in the blood and brain of rats. The brain concentration of II correlated well with the apparent sleeping time following a dose of I. In animals given a prior injection of fl-hydroxybutyrate, a known antagonist of the depressant effect of II, the sleep induced by I was delayed and shortened and the brain concentration of II found 1.5 hr after the dose of I was significantly reduced. This finding supported the view that the central depressant effect of I depends upon its metabolic conversion to II.
T H E CHEMICAL E N V I R O N M E N T 1706. The cement hazard underlined
Geiser, J. D. (1968). Les facteurs de sensibilisation dans l'ecz~ma au ciment. Schweiz. reed. Wschr. 98, 1193. Cement eczema is reported as being the most common occupational dermatosis encountered in Switzerland and constituted 2.38 ~o of 53,139 cases of dermatosis and 16.2 Yo of 7794 cases of eczema (contact dermatitis) seen by this author during the period 19471966. Patch testing of those suffering from cement dermatitis showed an incidence of sensitivity to dichromate of 92.4 Yo and to cobalt of 38.3 Yo. Less commonly demonstrated sensitivities were to arsenate, iodide, nickel and metavanadate. The major factors determining the development of cement dermatitis were considered to be the degree of exposure, the alkalinity of the material and the presence of metallic ions, principally of chromium and cobalt. No other metal was believed to contribute materially to the dermatosis picture. [We have previously drawn attention to the role of chromium in inducing cement dermatitis (Cited in F.C.T. 1966, 4, 631) and to the sensitization potential of both nickel and cobalt present in the material (ibm 1966, 4, 544).] 1707. Effect of cyanide on amino-acid transport in brain slices Levi, G. & Amaducci, L. (1968). Effect of acute cyanide intoxication on the active transport of amino acids in brain slices. J. Neurochem. 15, 459. Although it is difficult to correlate results obtained in vitro and in vivo, the mechanisms of amino-acid transport are believed to be the same in brain slices as in living brain. This belief has led to the use of brain slices to postulate the effects of various compounds on amino-acid transport in the intact brain. In the present study, brain slices from rats exposed to cyanide vapour for a short time