Pharmacology 14: 153-157 (1976)
Alkali Metal Ions and Ethanol Narcosis in Mice F.S. Messiha Department of Pharmacology and Therapeutics, and Department of Psychiatry, Texas Technical University School of Medicine, Lubbock, Tex.
Key Words. CsCl • Ethanol narcosis • Ethanol toxicity - LiCI • Liver alcohol dehydro genase • Liver aldehyde dehydrogenase • RbCl Abstract. The effect of an equimolar dose of LiCI, RbCl or CsCl on the depressant action of ethanol (ETOH) was studied as a function of duration of ETOH-mediated narcosis in mice. The alkali metal ions were administered acutely or semi-chronically prior to the administration of a narcotic dose of ETOH. Semi-chronic treatment with RbCl or CsCl resulted in decreased duration of ETOH-mediated narcosis, which was persistent for 5 days after discontinued administration of RbCl and CsCl. Conversely, a prolongation of ETOHproduced narcosis in Li-treated mice occurred only when ETOH was shortly administered after sub-chronic regimens of LiCI. Semi-chronic treatment with an equimolar dose of LiCI, RbCl or CsCl produced little changes in the specific activities of liver alcohol and aldehyde dehydrogenase. It is concluded that both Rb* and Cs* possess antidepressant properties and might be useful agents in negating the depressant action of ETOH and/or some of its toxic manifestations.
Received: September 17, 1975.
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The suggested use of lithium salts (Li) in the treatment of alcoholic subjects (5, 6) calls for an understanding of the effects of lithium on the depressant action of ethanol (ETOH). Rubidium (Rb) and cesium (Cs) salts might also be used in clinical trials to treat alcoholic patients since these alkali ions appear to have antidepressant properties (3, 7 -9 ). It is therefore of interest to study the effects of Li+, Rb+, and Cs+ on ETOH toxicity. Accordingly, it was decided to determine the effects of these three alkali metal ions on the central depressant action of ETOH in mice, using the duration of ETOH-mediated narcosis as the measured response. The effects of Li, Rb, and Cs salts on liver enzymes con cerned with the metabolism of ETOH, alcohol dehydrogenase (ADH, NAD, 1.1.1.1) and aldehyde dehydrogenase (ALDH, NAD, 1.2.1.3) were also studied.
Messiha
154
Methods Male albino Sprague-Dawley Swiss mice, 7 -9 weeks old and weighing 22-28 g, were used. They were housed in groups of 6 - 8 mice per cage in a room with 12 h light-dark cycle at 23-25 °C. The animals had free access to Purina laboratory food and water ad libitum for at least 2 weeks before experiments. ETOH narcosis was produced by an intraperitoneal injection of 25 % (v/v) ETOH (5.0 g/kg body weight) dissolved in saline. The chloride salts of Li, Rb, and Cs were dissolved in saline or 25 % ETOH and given by intraperitoneal injection (5.0 mEq/kg chloride salts). Saline-treated mice served as controls. In acute experi ments, the salts were given only once, cither simultaneous with or 20 min, 1, 3 or 5 days before administration of ETOH. In semi-chronic experiments, the salts were given once daily for 7 consecutive days and the last salt injection was given as in the acute experiments. The duration of ETOH-mediated narcosis was considered as the time between the animal’s loss of righting reflex (unable to right to normal position at least twice within 2 min) until the righting reflex was regained. The activity of liver enzymes was determined in mice sacrificed by decapitation at 72 h after the last injection of LiCl, RbCl or CsCl (5.0 mEq/kg body weight) given once daily for 7 consecutive days. The livers were quickly removed, weighed and individually homogenized in ice-cold 0.1 M KCI to obtain a 20 % homogenate (w/v). The homogenate was centrifuged at 22,000# for 90 min at 0 -4 °C. The supernatant obtained was assayed for ADH and ALDH as described by Blair and Vallee (1) and Blair and Bodley (2), respectively. An aliquot from the liver supernatant was used for the protein determinations by the biuret method. The specific activity of the enzymes is expressed as nAf/min/mg protein at 25 °C. The statistical significance of the results was analyzed by f-test for independent means.
Results Figure 1 summarizes the effects of acute and semi-chronic administration of LiCl, RbCl, or CsCl on the duration of ETOH-mediated narcosis in mice.
Table I. The effect of LiCl, RbCl or CsCl (5.0 mEq/kg/day) injected intraperitoneally for 7 consecutive days on specific activity of liver alcohol dehydrogenase (L-ADH) and liver aldehyde dehydrogenase (L-ALDH) of mice sacrificed 72 h after the last injection of the alkali metal ions L-ADH, nAf/min/mg protein
L-ALDH, nAf/min/mg protein
control
LiCl
RbCl
CsCl
control
LiCl
RbCl
CsCl
11.72 ± 0.62
12.10 t 0.73
11.87 ± 0.64
12.16 i 0.95
6.26 ±0.33
6.16 ± 1.08
5.45 ± 0.41
5.20 ± 0.24
(20)
(14)
(15)
(13)
(12)
(5)
(5)
(5)
Downloaded by: Leiden University Medisch Centrum 132.229.13.63 - 11/5/2018 10:38:41 AM
Control groups received injections of saline. The number of mice per group is shown in parentheses. Values are means t SE.
Ethanol Toxicity
155
Acute treatment with the alkali metal salts failed to affect the duration of ETOH-mediated narcosis significantly. Semi-chronic treatment with LiCl given 20 min before ETOH significantly prolonged ETOH-induced narcosis while the administration of LiCl at other times before the test failed to affect the duration of the ETOH narcosis. Semi-chronic treatment with RbCl, on the other hand, sig nificantly decreased the duration of ETOH-produced narcosis at all times except when RbCl was last given 20 min before the administration of ETOH (p < 0 .1). For example, administration of a narcotic dose of ETOH after 5 days of discon tinued semi-chronic treatment with RbCl resulted in mean sleep time of 35.3 ± 2.1 min as compared with 50.1 ± 3.3 min obtained for saline controls (p < 0.001). Likewise, semi-chronic treatment with CsCI shortened the duration of ETOH-induced narcosis significantly at all times except when the last injection of CsCI was given simultaneously with ETOH. Table I shows the specific activity of ADH and ALDH in the liver of mice given semi-chronic treatment with LiCl, RbCl or CsCI. No significant differences in the activity of the enzymes between the groups occurred.
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Fig. 1. The effect of LiCl, RbCl or CsCI (5.0 mEq/kg body weight, i.p.) given acutely (once) or semi-chronically (once daily for 7 days) on ETOH-produced narcosis in mice. The duration of ETOH narcosis is given in minutes as mean * SE. Number of animals used for each treatment is shown in parentheses. Time intervals between the last dose of alkali metal salts and the administration of a single narcotic dose of 25 % (v/v) ETOH solution (5.0 g/kg body weight, i.p.) is shown on the abscissa. * p < 0.05; ** p < 0.01; *** p < 0.001.
Messiha
156
Discussion Assuming that the length of ETOH-induced narcosis is one o f the measures of ETOH toxicity, the findings show that under certain experimental conditions Li+ can increase the toxicity of ETOH while Rb+ and Cs+ can reduce it. The prolongation of ETOH narcosis by Li+ was short-lived while the antagonistic action of Rb+ and Cs+ on ETOH narcosis persisted for at least 5 days after cessation of semi-chronic treatment. These differences in the duration of action of the alkali metal ions on ETOH toxicity may be related to the relatively short biological half-life of Li+ in the brain compared to the longer half-life of Rb+ and Cs+ (10). It is to be noted that the dose of the alkali metal salts used was above the therapeutic dose range. The mice showed little change in body weight during the semi-chronic administration of the salts, but the mice given LiCl and CsCl failed to gain weight at the same rate as control animals. The antidepressant action of Rb* in ETOH-produced narcosis test is con sistent with the reported CNS-stimulating property of Rb+ (7) that prompted clinical trials of Rb salts in the treatment of depression (4). Similarly, the pres ent findings also indicate that Cs* may have antidepressant properties. The effect of Li*, Rb* and Cs+ on ETOH narcosis cannot be accounted for by changes in the activity of the liver enzymes measured here which are involved in the metabolism of ETOH and acetaldehyde, since the activity of these en zymes was not altered by the alkali metal ions. It is more likely that intracellular ionic concentrations and active ion transport processes were affected by Li* and by Rb+ and Cs+ and that these effects were responsible for the actions of the ions on ETOH toxicity. However, the possibility of interference in ETOH ab sorption and its rate of elimination by the alkali metal ions cannot be excluded. Based on the present findings, it is conceivable that the consumption of excessive amounts of alcohol by patients during Li therapy might produce toxic manifestations. Accordingly, ingestion of alcohol during lithium therapy may be contraindicated. On the other hand, if clinical trials with Rb and Cs salts sub stantiate the present findings, then these alkali metal ions may be useful in modifying ETOH toxicity and/or might be used as prophylactic agents in the treatment of alcoholism.
1 2
Blair, A.H. and Vallee, B.L.: Some catalytic properties of human liver alcohol dehydro genase. Biochemistry, N.Y. 5: 2026-2034 (1966). Blair, A.H. and Bodley, F.H.: Human liver aldehyde dehydrogenase: partial purifica tion and properties. Can. J. Biochem. Physiol. 47: 265 272 (1969).
Downloaded by: Leiden University Medisch Centrum 132.229.13.63 - 11/5/2018 10:38:41 AM
References
Ethanol Toxicity
4
5 6 7 8 9 10
Carroll. B.J. and Sharp, P.T.: Rubidium and lithium: opposite effects on amine-medi ated excitement. Science. N.Y. 172: 1355-1357 (1971). Fieve, R.R.: Meitzer, H.; Dünner, D.L.: Levitt, M.: Mendlewicz, J., and Thomas, A.: Rubidium: biochemical, behavioral, and metabolic studies in humans. Am. J. Psychiat. 130: 55 61 (1973). Fries, H.: Experience with lithium carbonate treatment at a psychiatric department in the period 1964 1967. Acta psychiat. scand., suppl. 207, pp. 41 43 (1969). Kline, N.S.: Wren, J.C.: Cooper. T.B.: Varga, F... and Canal. O.: Evaluation of lithium therapy in chronic and periodic alcoholism. Am. J. med. Sei. 268: 15-22 (1974). Meitzer, H.L.: Taylor, R.M.: Platman, S.R., and Fieve, R.R.: Rubidium, a potential modifier of affect and behavior. Nature, Lond. 223: 321 322 (1969). Messiha, F.S. and Krantz, J.C., jr.: Effect of cesium ion on cerebral activity of the mouse. Am. J. Pharm. 145: 17 21 (1973). Messiha, F.S.: Cesium ion: antagonism to chlorpromazine —and L-dopa-induced be havioral depression in mice. J. Pharm. Pharmac. 27: 873-874 (1975). Messiha, F.S.: Distribution and retention of exogenously administered alkali metal ions in the mouse brain. Archs int. Pharmacodyn. Ther. (in press).
F.S. Messiha, Department of Pharmacology and Therapeutics, Texas Tech. University School of Medicine, Lubbock, TX 79411 (USA)
Downloaded by: Leiden University Medisch Centrum 132.229.13.63 - 11/5/2018 10:38:41 AM
3
157
Alkali Metal Ions and Ethanol Narcosis in Mice F.S. Messiha Department of Pharmacology and Therapeutics, and Department of Psychiatry, Texas Technical University School of Medicine, Lubbock, Tex.
Key Words. CsCl • Ethanol narcosis • Ethanol toxicity - LiCI • Liver alcohol dehydro genase • Liver aldehyde dehydrogenase • RbCl Abstract. The effect of an equimolar dose of LiCI, RbCl or CsCl on the depressant action of ethanol (ETOH) was studied as a function of duration of ETOH-mediated narcosis in mice. The alkali metal ions were administered acutely or semi-chronically prior to the administration of a narcotic dose of ETOH. Semi-chronic treatment with RbCl or CsCl resulted in decreased duration of ETOH-mediated narcosis, which was persistent for 5 days after discontinued administration of RbCl and CsCl. Conversely, a prolongation of ETOHproduced narcosis in Li-treated mice occurred only when ETOH was shortly administered after sub-chronic regimens of LiCI. Semi-chronic treatment with an equimolar dose of LiCI, RbCl or CsCl produced little changes in the specific activities of liver alcohol and aldehyde dehydrogenase. It is concluded that both Rb* and Cs* possess antidepressant properties and might be useful agents in negating the depressant action of ETOH and/or some of its toxic manifestations.
Received: September 17, 1975.
Downloaded by: Leiden University Medisch Centrum 132.229.13.63 - 11/5/2018 10:38:41 AM
The suggested use of lithium salts (Li) in the treatment of alcoholic subjects (5, 6) calls for an understanding of the effects of lithium on the depressant action of ethanol (ETOH). Rubidium (Rb) and cesium (Cs) salts might also be used in clinical trials to treat alcoholic patients since these alkali ions appear to have antidepressant properties (3, 7 -9 ). It is therefore of interest to study the effects of Li+, Rb+, and Cs+ on ETOH toxicity. Accordingly, it was decided to determine the effects of these three alkali metal ions on the central depressant action of ETOH in mice, using the duration of ETOH-mediated narcosis as the measured response. The effects of Li, Rb, and Cs salts on liver enzymes con cerned with the metabolism of ETOH, alcohol dehydrogenase (ADH, NAD, 1.1.1.1) and aldehyde dehydrogenase (ALDH, NAD, 1.2.1.3) were also studied.
Messiha
154
Methods Male albino Sprague-Dawley Swiss mice, 7 -9 weeks old and weighing 22-28 g, were used. They were housed in groups of 6 - 8 mice per cage in a room with 12 h light-dark cycle at 23-25 °C. The animals had free access to Purina laboratory food and water ad libitum for at least 2 weeks before experiments. ETOH narcosis was produced by an intraperitoneal injection of 25 % (v/v) ETOH (5.0 g/kg body weight) dissolved in saline. The chloride salts of Li, Rb, and Cs were dissolved in saline or 25 % ETOH and given by intraperitoneal injection (5.0 mEq/kg chloride salts). Saline-treated mice served as controls. In acute experi ments, the salts were given only once, cither simultaneous with or 20 min, 1, 3 or 5 days before administration of ETOH. In semi-chronic experiments, the salts were given once daily for 7 consecutive days and the last salt injection was given as in the acute experiments. The duration of ETOH-mediated narcosis was considered as the time between the animal’s loss of righting reflex (unable to right to normal position at least twice within 2 min) until the righting reflex was regained. The activity of liver enzymes was determined in mice sacrificed by decapitation at 72 h after the last injection of LiCl, RbCl or CsCl (5.0 mEq/kg body weight) given once daily for 7 consecutive days. The livers were quickly removed, weighed and individually homogenized in ice-cold 0.1 M KCI to obtain a 20 % homogenate (w/v). The homogenate was centrifuged at 22,000# for 90 min at 0 -4 °C. The supernatant obtained was assayed for ADH and ALDH as described by Blair and Vallee (1) and Blair and Bodley (2), respectively. An aliquot from the liver supernatant was used for the protein determinations by the biuret method. The specific activity of the enzymes is expressed as nAf/min/mg protein at 25 °C. The statistical significance of the results was analyzed by f-test for independent means.
Results Figure 1 summarizes the effects of acute and semi-chronic administration of LiCl, RbCl, or CsCl on the duration of ETOH-mediated narcosis in mice.
Table I. The effect of LiCl, RbCl or CsCl (5.0 mEq/kg/day) injected intraperitoneally for 7 consecutive days on specific activity of liver alcohol dehydrogenase (L-ADH) and liver aldehyde dehydrogenase (L-ALDH) of mice sacrificed 72 h after the last injection of the alkali metal ions L-ADH, nAf/min/mg protein
L-ALDH, nAf/min/mg protein
control
LiCl
RbCl
CsCl
control
LiCl
RbCl
CsCl
11.72 ± 0.62
12.10 t 0.73
11.87 ± 0.64
12.16 i 0.95
6.26 ±0.33
6.16 ± 1.08
5.45 ± 0.41
5.20 ± 0.24
(20)
(14)
(15)
(13)
(12)
(5)
(5)
(5)
Downloaded by: Leiden University Medisch Centrum 132.229.13.63 - 11/5/2018 10:38:41 AM
Control groups received injections of saline. The number of mice per group is shown in parentheses. Values are means t SE.
Ethanol Toxicity
155
Acute treatment with the alkali metal salts failed to affect the duration of ETOH-mediated narcosis significantly. Semi-chronic treatment with LiCl given 20 min before ETOH significantly prolonged ETOH-induced narcosis while the administration of LiCl at other times before the test failed to affect the duration of the ETOH narcosis. Semi-chronic treatment with RbCl, on the other hand, sig nificantly decreased the duration of ETOH-produced narcosis at all times except when RbCl was last given 20 min before the administration of ETOH (p < 0 .1). For example, administration of a narcotic dose of ETOH after 5 days of discon tinued semi-chronic treatment with RbCl resulted in mean sleep time of 35.3 ± 2.1 min as compared with 50.1 ± 3.3 min obtained for saline controls (p < 0.001). Likewise, semi-chronic treatment with CsCI shortened the duration of ETOH-induced narcosis significantly at all times except when the last injection of CsCI was given simultaneously with ETOH. Table I shows the specific activity of ADH and ALDH in the liver of mice given semi-chronic treatment with LiCl, RbCl or CsCI. No significant differences in the activity of the enzymes between the groups occurred.
Downloaded by: Leiden University Medisch Centrum 132.229.13.63 - 11/5/2018 10:38:41 AM
Fig. 1. The effect of LiCl, RbCl or CsCI (5.0 mEq/kg body weight, i.p.) given acutely (once) or semi-chronically (once daily for 7 days) on ETOH-produced narcosis in mice. The duration of ETOH narcosis is given in minutes as mean * SE. Number of animals used for each treatment is shown in parentheses. Time intervals between the last dose of alkali metal salts and the administration of a single narcotic dose of 25 % (v/v) ETOH solution (5.0 g/kg body weight, i.p.) is shown on the abscissa. * p < 0.05; ** p < 0.01; *** p < 0.001.
Messiha
156
Discussion Assuming that the length of ETOH-induced narcosis is one o f the measures of ETOH toxicity, the findings show that under certain experimental conditions Li+ can increase the toxicity of ETOH while Rb+ and Cs+ can reduce it. The prolongation of ETOH narcosis by Li+ was short-lived while the antagonistic action of Rb+ and Cs+ on ETOH narcosis persisted for at least 5 days after cessation of semi-chronic treatment. These differences in the duration of action of the alkali metal ions on ETOH toxicity may be related to the relatively short biological half-life of Li+ in the brain compared to the longer half-life of Rb+ and Cs+ (10). It is to be noted that the dose of the alkali metal salts used was above the therapeutic dose range. The mice showed little change in body weight during the semi-chronic administration of the salts, but the mice given LiCl and CsCl failed to gain weight at the same rate as control animals. The antidepressant action of Rb* in ETOH-produced narcosis test is con sistent with the reported CNS-stimulating property of Rb+ (7) that prompted clinical trials of Rb salts in the treatment of depression (4). Similarly, the pres ent findings also indicate that Cs* may have antidepressant properties. The effect of Li*, Rb* and Cs+ on ETOH narcosis cannot be accounted for by changes in the activity of the liver enzymes measured here which are involved in the metabolism of ETOH and acetaldehyde, since the activity of these en zymes was not altered by the alkali metal ions. It is more likely that intracellular ionic concentrations and active ion transport processes were affected by Li* and by Rb+ and Cs+ and that these effects were responsible for the actions of the ions on ETOH toxicity. However, the possibility of interference in ETOH ab sorption and its rate of elimination by the alkali metal ions cannot be excluded. Based on the present findings, it is conceivable that the consumption of excessive amounts of alcohol by patients during Li therapy might produce toxic manifestations. Accordingly, ingestion of alcohol during lithium therapy may be contraindicated. On the other hand, if clinical trials with Rb and Cs salts sub stantiate the present findings, then these alkali metal ions may be useful in modifying ETOH toxicity and/or might be used as prophylactic agents in the treatment of alcoholism.
1 2
Blair, A.H. and Vallee, B.L.: Some catalytic properties of human liver alcohol dehydro genase. Biochemistry, N.Y. 5: 2026-2034 (1966). Blair, A.H. and Bodley, F.H.: Human liver aldehyde dehydrogenase: partial purifica tion and properties. Can. J. Biochem. Physiol. 47: 265 272 (1969).
Downloaded by: Leiden University Medisch Centrum 132.229.13.63 - 11/5/2018 10:38:41 AM
References
Ethanol Toxicity
4
5 6 7 8 9 10
Carroll. B.J. and Sharp, P.T.: Rubidium and lithium: opposite effects on amine-medi ated excitement. Science. N.Y. 172: 1355-1357 (1971). Fieve, R.R.: Meitzer, H.; Dünner, D.L.: Levitt, M.: Mendlewicz, J., and Thomas, A.: Rubidium: biochemical, behavioral, and metabolic studies in humans. Am. J. Psychiat. 130: 55 61 (1973). Fries, H.: Experience with lithium carbonate treatment at a psychiatric department in the period 1964 1967. Acta psychiat. scand., suppl. 207, pp. 41 43 (1969). Kline, N.S.: Wren, J.C.: Cooper. T.B.: Varga, F... and Canal. O.: Evaluation of lithium therapy in chronic and periodic alcoholism. Am. J. med. Sei. 268: 15-22 (1974). Meitzer, H.L.: Taylor, R.M.: Platman, S.R., and Fieve, R.R.: Rubidium, a potential modifier of affect and behavior. Nature, Lond. 223: 321 322 (1969). Messiha, F.S. and Krantz, J.C., jr.: Effect of cesium ion on cerebral activity of the mouse. Am. J. Pharm. 145: 17 21 (1973). Messiha, F.S.: Cesium ion: antagonism to chlorpromazine —and L-dopa-induced be havioral depression in mice. J. Pharm. Pharmac. 27: 873-874 (1975). Messiha, F.S.: Distribution and retention of exogenously administered alkali metal ions in the mouse brain. Archs int. Pharmacodyn. Ther. (in press).
F.S. Messiha, Department of Pharmacology and Therapeutics, Texas Tech. University School of Medicine, Lubbock, TX 79411 (USA)
Downloaded by: Leiden University Medisch Centrum 132.229.13.63 - 11/5/2018 10:38:41 AM
3
157
