Differences In Blood Ethanol Concentrations Research Articles

Facial changes in individuals deceased from ethanol poisoning

BACKGROUND: Changes in the facial area (facial edema, its purplish or bluish color, drooling, tearing, and a sign described by A.P. Kurdyumov) are among the most commonly observed signs of ethanol poisoning. However, their diagnostic capabilities are not investigated, and the mechanisms of development are not described. AIM: To study the occurrence of changes in the facial area in individuals who died from ethanol poisoning. From a modern perspective, the mechanism of their development, characteristics, and specificity were assessed. MATERIALS AND METHODS: A single-center retrospective observational cross-sectional study was conducted based on the archive of the State Budgetary Healthcare Institution of Moscow Region “Bureau of Forensic Medical Examination,” including cases of death from January 1, 2020, to December 31, 2020. Cases were grouped into five categories: ethanol poisoning, poisoning with other alcohols, asphyxia, other violent causes of death, and natural death. RESULTS: The study included 1,181 cases, with a median age of 52 (range, 19–95) years. Women were older, with no significant difference in blood ethanol concentration. Facial puffiness was observed in 53.1% of ethanol poisoning cases and bluish discoloration in 59.5%. The sign described by A.P. Kurdyumov was less frequently observed. Facial puffiness (p=0.002) and the sign described by A.P. Kurdyumov (p=0.014) were more common in poisoning with other alcohols than in deaths from asphyxia. However, no such differences were observed for facial bluish discoloration (p=0.176). Facial bluish discoloration had the highest sensitivity in both alcohol and other alcohol poisoning cases (59.53% and 40.74%, respectively) but had the lowest specificity in the same groups among the examined signs. The sign described by A.P. Kurdyumov had the highest specificity among those examined for both ethanol poisoning and poisoning with other alcohols. CONCLUSION: In ethanol poisoning, facial bluish discoloration was the most sensitive sign, and the sign described by A.P. Kurdyumov was the most specific among the analyzed signs. The examined signs were observed in both ethanol and other alcohol poisoning but less frequently. The forensic medical signs considered are largely similar to the clinical signs observed in flush syndrome.

Orexinergic lateral hypothalamus (LH) projections to medial septum (MS) modulate ethanol-induced sedation in male and female mice and binge-like ethanol drinking in male mice only

Orexin in both the lateral hypothalamus (LH) and medial septum (MS) is involved in sleep- and consciousness-related conditions. Since orexin modulates the intoxicating as well as rewarding effects of ethanol, this study focused on the role of orexin-projecting neurons from the LH to the MS, and this neurocircuit's role in mediating the sedative effects of alcohol. Drinking-in-the-Dark (DID) behavior was also assessed as a measure of the role of the LH-MS pathway in modulating binge-like ethanol intake, with a particular focus on sex differences in both behavioral paradigms. Male and female Hcrt-ires-cre mice received cannulation in the MS, while the LH was injected bilaterally with cre-dependent excitatory (Gq) Designer Receptor Exclusively Activated by Designer Drug (DREADD), inhibitory (Gi) DREADD or control virus. All subjects received a 3.75 g/kg dose of 20 % ethanol intraperitoneally and the sedative effect was assessed by the loss of righting reflex (LORR). After behavioral testing, brains were used for c-Fos immunohistochemistry analyses. A separate cohort of mice was used for a 2-week DID protocol using excitatory (Gq) DREADD and control virus. Gq DREADD-induced activation of the orexin neurocircuitry from the LH to the MS significantly reduced sedation time in both female and male mice. Furthermore, CNO treatment failed to alter ethanol sedation times in both animals expressing Gi DREADDs and control virus. There were no significant differences in blood ethanol concentrations (BECs) in any experimental group, suggesting that changes in sedation were not due to treatment-induced alterations of ethanol metabolism. Interestingly, in the DID study, only male mice decreased their ethanol consumption when Gq DREADDs were activated. These results provide novel evidence on the role played by this orexinergic LH to MS circuit on the sedative effects of ethanol and ethanol consumption in a sex-dependent manner. Thus, the MS should be considered further as a novel sexually dimorphic target.

Agmatine prevents development of tolerance to anti-nociceptive effect of ethanol in mice.

Drug tolerance is directly correlated with drug abuse and physical dependence. The development of tolerance is manifested as the decline in pharmacological responses of drugs following repeated administration of the constant dose. The present study evaluated the effect of agmatine in ethanol-induced anti-nociception and tolerance in the tail-flick assay in mice. In an acute protocol, ethanol (1 and 2g/kg, i.p. [intraperitoneally]) and agmatine (20 and 40 μg/mouse, i.c.v. [intracerebroventricularly]) produced significant analgesic effects in mice, as was evident from the increased baseline tail-flick latency when tested 20 minutes after their administration. Agmatine in a per se non-effective dose (5 μg/mouse, i.c.v.), L-arginine (40 μg/mouse, i.c.v.), and arcaine (25 μg/mouse, i.c.v.) significantly potentiated the anti-nociceptive effect of ethanol. Blood ethanol analysis showed no significant differences in blood ethanol concentration between ethanol/saline- and ethanol/agmatine-treated mice, suggesting that the effects of agmatine were not due to any possible effects on the pharmacokinetics of ethanol. In a separate study, mice were injected with ethanol (2g/kg, i.p., 12%) or saline (1mL/kg, i.p.) once daily for 9 days. On days 1, 3, 5, 7, and 9 of the experiment, they were subjected to the tail-flick test. Agmatine (5-20 μg/mouse, i.c.v.), L-arginine (40 μg/mouse, i.c.v.), arcaine (25 μg/mouse, i.c.v.), aCSF (2 μL/mouse, i.c.v.), or saline (1mL/kg, i.p.) was administered daily prior to the first daily ethanol or saline injections, and reaction latencies were determined in the tail-flick assay. Injections of agmatine, L-arginine, and arcaine prevented the development of tolerance to ethanol-induced analgesia. Given that agmatine and its endogenous modulation can prevent tolerance to the anti-nociceptive effects of ethanol, these data suggest it as a possible new therapeutic strategy for the treatment of alcohol use disorder and associated complications.

Voluntary ethanol consumption during early social isolation and responding for ethanol in adulthood.

Little is known about the influence of rearing environments concurrent with voluntary intermittent access to ethanol on subsequent adult ethanol-related behaviors. Previous research has shown that adult rats reared in post-weaning, social isolation conditions (IC) respond more for operant ethanol compared to laboratory standard conditions (SC). Ethanol-exposed adolescents tend to consume more ethanol in adulthood than rats exposed as adults. The current study examined voluntary ethanol consumption during adolescence between IC and SC rats, subsequent operant responding for ethanol, and extinction of responding in the same rats as adults. Differences in ethanol metabolism may alter the amount of reward value per unit of ethanol consumed. Therefore, the current study also examined blood ethanol concentrations (BEC) between IC rats and SC rats. Ethanol-naïve Long-Evans rats arrived in the lab at postnatal day (PND) 21 and were separated into either IC or SC where they remained for the duration of the experiments. On PND 27, rats received intermittent access to 20% ethanol (3 days/week) for 4 or 6 weeks. Rats in the 6-week cohort were then trained to lever press for 20% ethanol in 30-min sessions followed by extinction. A separate cohort was reared in IC or SC, injected with 1.5 or 3.0g/kg of ethanol (intraperitoneally [i.p.]), followed by BEC measurement. Overall, IC rats had higher ethanol preference and consumption during adolescence/early adulthood. IC and SC rats did not differ in their rates of operant responding for ethanol, and SC rats responded more than IC rats during extinction. There were no differences in BEC between IC and SC rats. These findings highlight the importance of the environment during rat adolescent development with isolation conditions increasing binge-like drinking and ethanol preference after 3-4 weeks without differences in metabolism as a potential factor. Additionally, the findings indicate that intermittent adolescent access to ethanol may change typical differences in operant responding patterns between IC and SC rats in adulthood.

Sweetened ethanol drinking during social isolation: enhanced intake, resistance to genetic heterogeneity and the emergence of a distinctive drinking pattern in adolescent mice.

With its ease of availability during adolescence, sweetened ethanol ('alcopops') is consumed within many contexts. We asked here whether genetically based differences in social motivation are associated with how the adolescent social environment impacts voluntary ethanol intake. Mice with previously described differences in sociability (BALB/cJ, C57BL/6J, FVB/NJ and MSM/MsJ strains) were weaned into isolation or same-sex pairs (postnatal day, PD, 21), and then given continuous access to two fluids on PDs 34-45: one containing water and the other containing an ascending series of saccharin-sweetened ethanol (3-6-10%). Prior to the introduction of ethanol (PDs 30-33), increased water and food intake was detected in some of the isolation-reared groups, and controls indicated that isolated mice also consumed more 'saccharin-only' solution. Voluntary drinking of 'ethanol-only' was also higher in a subset of the isolated groups on PDs 46-49. However, sweetened ethanol intake was increased in all isolated strain × sex combinations irrespective of genotype. Surprisingly, blood ethanol concentration (BEC) was not different between these isolate and socially housed groups 4 h into the dark phase. Using lickometer-based measures of intake in FVB mice, we identified that a predominance of increased drinking during isolation transpired outside of the typical circadian consumption peak, occurring ≈8.5 h into the dark phase, with an associated difference in BEC. These findings collectively indicate that isolate housing leads to increased consumption of rewarding substances in adolescent mice independent of their genotype, and that for ethanol this may be because of when individuals drink during the circadian cycle.

Endogenous Ethanol Production Levels in Saudi Arabia Residents

The word “endogenous” means produced or originating from within the body, so endogenous ethanol therefore implies a spontaneous auto regulation of ethanol through various human metabolic processes. In the current research, endogenous ethanol concentrations in blood were determined by sensitive headspace gas chromatography/mass Spectrophotometry in 1400 residents of Saudi Arabia. The subjects were from 14 nationalities, of both sexes and of different age groups. There was no significance difference in blood ethanol concentration between nationalities or between sexes within and between nationalities. The data was extracted and the overall mean ± SD, minimum, maximum, 5% percentile and 95% percentile were 0.14, ± 0.35, 0.00, 1.53 , 0.00, 1.20 mg/dl respectively. The values of blood ethanol concentration as reported in this study indicate they are far too low to have any forensic significance.

Ethanol intake and ethanol-conditioned place preference are reduced in mice treated with the bioflavonoid agent naringin

Recently, PPAR-γ activation has emerged as a potential treatment for alcoholism. However, the adverse effects of synthetic PPAR-γ activators, despite being effective drugs, prompted the need for novel PPAR-γ agonists that retain efficacy and potency with a lower potential of side effects. Hence, naringin, a bioflavonoid isolated from citrus fruits and recently identified as a natural ligand of PPAR-γ, has begun to be evaluated for treatment of alcoholism. It is well known to possess several therapeutic benefits in addition to its anti-anxiety and antidepressant properties. In the present study, we assessed whether naringin treatment possesses anti-ethanol reward properties in C57BL/6 mice. We used the two-bottle choice drinking paradigm and ethanol-induced conditioned place preference (CPP) to examine the effect of naringin treatment on ethanol drinking. Results have shown that, compared with vehicle, naringin (10–100 mg/kg) significantly and dose-dependently decreased voluntary ethanol intake and preference in a two-bottle choice drinking paradigm [3–15% (v/v) escalating over 2 weeks], with no significant effect observed on saccharin [0.02–0.08% (w/v)] or on quinine [15–60 μM (w/v)] intake. In addition, there was no significant difference in blood ethanol concentration (BEC) between groups following naringin administration of 3 g of ethanol/kg body weight. Interestingly, when mice were treated with vehicle or naringin (30 mg/kg) before injection of ethanol (1.5 g/kg) during conditioning days, naringin inhibited the acquisition of ethanol-CPP. More importantly, these effects were significantly attenuated when mice were pre-injected with the peroxisome proliferator-activated receptor-γ (PPAR-γ) antagonist, GW9662. Taken together, the present findings are the first to implicate naringin and PPAR-γ receptors in the behavioral and reward-related effects of ethanol and raise the question of whether specific drugs that target PPAR-γ receptors could potentially reduce excessive ethanol consumption and preference.

The circadian Per1 and Per2 genes influence alcohol intake, reinforcement, and blood alcohol levels

BackgroundPerturbations in the function of core circadian clock components such as the Period (Per) family of genes are associated with alcohol use disorder, and disruptions in circadian cycles may contribute to alcohol abuse and relapse. This study tested ethanol consumption, reinforcement, and metabolism in mice containing functional mutations in Per1 and/or Per2 genes on an ethanol-preferring background, C57BL/6J mice. MethodsMice were tested in: (A) free-access intake with ascending concentrations of ethanol (2–16%, v/v), (B) conditioned place preference using ethanol (2g/kg for males; 2.5g/kg for females) vs. saline injections, (C) recovery of the righting reflex following a 4g/kg bolus of ethanol, and (D) blood ethanol levels 1h after a 2g/kg bolus of ethanol. ResultsAll Per mutant (mPer) mice showed increased ethanol intake and condition place preference compared to controls. There were also genotypic differences in blood ethanol concentration: in males, only mPer1 mice showed a significantly higher blood ethanol concentration than WT mice, but in females, all mPer mice showed higher blood ethanol levels than WT mice. ConclusionsMutation of either Per1 or Per2, as well as mutations of both genes, increases ethanol intake and reinforcement in an ethanol-preferring mouse model. In addition, this increase in ethanol seeking behavior seems to result both from a change in ethanol metabolism and a change in reward responding to ethanol, but not from any change in sensitivity to ethanol's sedating effects.

Proopiomelanocortin Peptides Are Not Essential for Development of Ethanol‐Induced Behavioral Sensitization

Behavioral sensitization is a result of neuroadaptation to repeated drug administration and is hypothesized to reflect an increased susceptibility to drug abuse. Proopiomelanocortin (POMC) derived peptides including beta-endorphin and alpha-melanocyte stimulating hormone have been implicated in development of behavioral sensitization and the reinforcing effects of alcohol and other drugs of abuse. This study used a genetically engineered mouse strain that is deficient for neural POMC to directly determine if any POMC peptides are necessary for the development of ethanol-induced locomotor sensitization. Adult female mice deficient for POMC in neurons only (Pomc(-/-)Tg/Tg, KO) and wildtype (Pomc(+/+)Tg/Tg, WT) littermates were injected once daily with either saline or ethanol (i.p.) for 12 to 13 days. On ethanol test day (day 13 or 14) all mice from both treatment groups received an i.p. injection of ethanol immediately before a 15-minute analysis of locomotor activity. Blood ethanol concentration (BEC) was measured on ethanol test day immediately following the test session. Baseline locomotor activity was measured for 15 minutes after a saline injection 2 days later in both groups. There was no significant difference in BEC between genotypes (WT = 2.11 +/- 0.06; KO = 2.03 +/- 0.08 mg/ml). Both WT and nPOMC-deficient mice treated repeatedly with ethanol demonstrated a significant increase in locomotor activity on test day when compared to repeated saline-treated counterparts. In addition, mice of both genotypes in the repeated saline groups showed a significant locomotor stimulant response to acute ethanol injection. Central POMC peptides are not required for either the acute locomotor stimulatory effect of ethanol or the development of ethanol-induced locomotor sensitization. While these peptides may modulate other ethanol-associated behaviors, they are not essential for development of behavioral sensitization.

Quantitative Trait Locus Mapping for Acute Functional Tolerance to Ethanol in the L × S Recombinant Inbred Panel

Acute functional tolerance (AFT) develops shortly after ethanol administration, and is determined as the change in brain or blood ethanol concentration (BEC) measured at 2 behavioral or physiological endpoints. Acute functional tolerance studies in some rodent strains support a long-held hypothesis that more sensitive strains develop more within-session tolerance. We used the new, 74-strain L x S recombinant inbred (RI) panel, developed from inbred long-sleep (ILS) and inbred short-sleep (ISS) strains, to revisit this hypothesis and to map quantitative trait loci (QTLs) for AFT. We report replication of QTL regions reported by earlier studies of AFT and preliminary application of a coarse single nucleotide polymorphism map analysis to limit QTL intervals for subsequent candidate gene hypotheses. Acute functional tolerance was assayed using a test of ataxia: loss and regain of balance on a stationary wooden dowel. Following an initial dose of 1.75 g/kg, BEC was measured at initial loss (BEC(0)) and regain of balance (BEC(1)). A second injection (2.0 g/kg) was administered and blood taken at the second regain of balance (BEC(2)). Acute functional tolerance was calculated as a difference score in 2 ways: (1) between BEC at the 2 successive regains of balance (AFT(1)), or (2) as the difference in BEC at final regain and at initial loss of balance (AFT(2)). We mapped QTLs for BEC(0), a measure of initial sensitivity, and both AFT scores. All 4 parental strains (LS, SS, ILS, and ISS) developed tolerance, replicating previous published reports. There were significant sex effects for 3 of these strains. The L x S panel showed a 128-fold range in tolerance, with a few strains showing negative tolerance (sensitization). The ISS surpassed the next highest RI strain by 55% and was more than 4 times greater than SS. Heritability estimates for both AFT measures were close to 0.25 for both sexes. One significant QTL accounting for approximately 18% of phenotypic variance (V(P)), on chromosome 12 (AFT(1)), and 1 suggestive QTL (16% V(P)), on chromosome 16 (AFT(2)), were identified. These QTLs replicated regions reported in other studies. A multiple QTL model incorporating the effects of all significant interacting QTLs was developed, explaining almost 60% of V(P). The chromosome 12 region was further investigated by haplotype analysis, which identified many nonpolymorphic regions within the confidence interval, and possible candidate genes in the polymorphic regions. Both SS and ISS developed greater AFT, assessed by both methods, than LS and ILS; this difference was significant in virtually all sex by strain comparisons. In the L x S RI, there was no correlation between initial sensitivity, measured by BEC at initial loss of balance, and either measure of AFT, on a stationary dowel. These results indicate that in this model system, initial sensitivity does not predict tolerance. Several QTLs for tolerance were identified; candidates in the narrowed chromosome 12 region, which has been reported in 2 other mapping studies, merit additional study.

Autobrewing revisited: endogenous concentrations of blood ethanol in residents of the United Arab Emirates.

Endogenous ethanol concentrations in blood were determined by sensitive headspace gas chromatography/mass spectrometry in 1557 residents of the United Arab Emirates. The subjects were from 13 nationalities, of both sexes and of different age groups. There was no significant difference in blood ethanol concentration between nationalities or between sexes within and between nationalities. The data was pooled and the overall median, minimum, maximum, 25% percentile and 75% percentile were 0.04, 0.00, 3.52, 0.01 and 0.09 mg/dl respectively. The values of blood ethanol concentration as reported in this study indicate that they are far too low to have any forensic significance.

Freely accessible water does not decrease consumption of ethanol liquid diets

In experimental studies, liquid ethanol diets are usually given as the sole source of nutrition and fluid. Two series of experiments were conducted to examine the effect of freely accessible water on the consumption of ethanol liquid diets in male Long–Evans rats. The consumption of diets and subsequent learning ability of rats were first examined in animals given twice-daily saline injections. One group received diet with no access to water for 12 weeks and was subsequently given free access to water with diets for an additional 12 weeks. A second group was given diet and water ad libitum for 24 weeks. Control animals received an isocaloric sucrose-containing diet (with or without ad libitum access to water). Subsequently, rats were tested for active avoidance learning. In the first 12 weeks, animals with ad libitum access to water drank more diet than did water-restricted animals, and previously water-restricted animals increased their diet consumption when access to water was freely available. All water-restricted animals, in both ethanol- and sucrose-treated groups, showed deficits in active avoidance learning, whereas only ethanol-treated animals in groups with ad libitum access to water showed learning deficits. In the second series of experiments, the effect of saline injections on diet consumption, both in the presence and absence of water, was examined. Although saline injections were associated with decreased diet consumption, there was no effect of free access to water. No differences in blood ethanol concentration were seen among groups. Findings obtained from both series of studies demonstrate that consumption of a Sustacal-based liquid ethanol diet does not decrease if access to water is freely available.

Mapping murine loci for physical dependence on ethanol.

Alcoholism is associated with withdrawal (physical dependence), tolerance, or a maladaptive pattern of alcohol (ethanol) use. The well-documented difference in susceptibility to withdrawal after chronic ethanol exposure between the C57BL/6J and DBA/2J mouse strains provides an excellent starting point for dissecting genetic influences involved in physical dependence on ethanol. A quantitative trait locus (QTL) identifies the genomic location of a gene (or genes) affecting a trait of interest. A genome-wide QTL mapping study was carried out to dissect the multifactorial nature of withdrawal after chronic ethanol exposure using 400 B6D2F2 mice. To induce physical dependence, we used a standard paradigm in which mice were exposed to ethanol vapor for 72 h. The mice were then tested hourly for handling-induced convulsions (HICs) for 10 h and at hours 24 and 25. Ethanol withdrawal severity was first computed as the area under the 25-h HIC curve. Separate regression residuals were then calculated that corrected for individual differences in blood ethanol concentration at the time of withdrawal and baseline HIC severity (i.e. before ethanol exposure). Statistical mapping yielded significant evidence ( P<0.00005) for QTLs on chromosomes 19 and distal 1 that account for 45% of the genetic variance in ethanol withdrawal severity. The F2 results also provide supporting evidence for a sex-limited QTL on chromosome 13, and QTLs on chromosomes 4 and proximal 1, which may account for an additional 38% of the genetic variance. The distal chromosome 1 QTL is a locus of major effect, accounting for 26% of the genetic variance. Experiments using two congenic strains more precisely mapped this QTL. The QTLs map near candidate genes involved in neurosteroid biosynthesis and signal transduction. Syntenic homology between human and mouse chromosomes suggests that genes related to physical dependence on ethanol may localize to human chromosome regions 10q23-q26, 1q21-q43, 2q11-q32, 5p15/5q14-q21, and 9p24-p22.

Ethanol Tolerance and Withdrawal Responses in GABAA Receptor Alpha 6 Subunit Null Allele Mice and in Inbred C57BL/6J and Strain 129/SvJ Mice

We have been using a genetic strategy to define the contribution of specific candidate genes, such as those encoding subunits of the gamma-aminobutyric acid type A receptor, to various ethanol sensitive responses. We have used the gene knockout approach in mouse embryonic stem cells to create mice in which the gene encoding the alpha6 subunit of the gamma-aminobutyric acid type A receptor is rendered nonfunctional. In the present report, we provide a detailed characterization of several behavioral responses to ethanol in these null allele mice. In a separate series of experiments, behavioral response to ethanol was compared between two inbred strains of mice that are commonly used as background stock in knockout experiments, namely C57BL/6J and Strain 129/SvJ. Wild type (alpha6+/+) and homozygous null allele (alpha6-/-) mice did not differ to the ataxic effects of ethanol on acute functional tolerance (95.8 +/- 8.7 vs. 98.8 +/- 5.7 mg/dl +/- SEM, respectively). Withdrawal hyperexcitability was assessed following chronic exposure to ethanol vapor (EtOH) or air (CONT) in inhalation chambers in a multiple withdrawal treatment paradigm. At the end of the last treatment cycle, mice were scored for handling induced convulsions (HIC). After adjusting for differences in blood ethanol concentration between genotypes at the end of the final treatment cycle, we observed a greater area under the 24-hr HIC curves in mice treated with ethanol (p < 0.0001) but did not detect an effect of genotype (alpha6+/+/CONT 3.1 +/- 2.0; alpha6-/-/CONT 5.5 +/- 2.5; alpha6+/+/EtOH 30.1 +/- 6.2; alpha6-/-/EtOH 33.0 +/- 5.8 mean units +/- SEM). We also examined these mice for differences in protracted tolerance; at approximately 26 hr into the final withdrawal cycle, each mouse was injected with ethanol (3.5 mg/g body weight) and sleep time was measured. We detected a significant effect of treatment (p < 0.001) with ethanol-treated mice demonstrating signs of tolerance as reflected by a reduction in duration of sleep time. However, effect of genotype was not significant (alpha6+/+/CONT 57.4 +/- 7.6; alpha6-/-/CONT 59.0 +/- 7.6; alpha6+/ +/EtOH 34.8 +/- 7.4; alpha6-/-/EtOH 30.8 +/- 5.6 min +/- SEM). From these data we conclude that the alpha6 subunit of the GABA(A)-R exerts little if any influence on acute functional tolerance, withdrawal hyperexcitability, or protracted tolerance. Strain 129/SvJ and C57BL/6J mice were also compared for acute functional tolerance and were found not to differ (96.3 +/- 4.4 vs. 94.8 +/- 11.3 mg/dl +/- SEM, respectively). Withdrawal hyperexcitability was assessed by comparing the area under the 24 hr HIC curves. Strain 129/SvJ mice displayed a much greater basal HIC response compared to C57BL/6J mice (19.8 +/- 4.3 vs. 0.2 +/- 0.2 mean units +/- SEM, respectively); after adjusting for differences in blood ethanol concentration between strains at the end of the final ethanol treatment cycle, the HIC response was markedly enhanced by ethanol treatment in Strain 129/SvJ mice but not in C57BL/6J mice (50.4 +/- 3.1 vs. 9.5 +/- 5.4 mean units +/- SEM, respectively). The effects of treatment (p < 0.0001), strain (p < 0.0001), and the interaction of strain with treatment (p < 0.01) were significant. Since many gene knockout mice are maintained on a mixed genetic background of Strain 129/SvJ and C57BL/6J, we conclude that significant differences in tests of withdrawal hyperexcitability may be confounded by the influence of genes that cosegregate with the gene targeted allele.

Wheat gluten-based diet retarded ethanol metabolism by altering alcohol dehydrogenase and not carnitine status in adult rats.

The objective of this study was to determine the effect of a lysine-deficient diet on carnitine status in adult rats and subsequently on ethanol metabolism. Adult male rats were fed either the AIN-76 diet (NS), the AIN-76 diet with wheat gluten (WG) replacing casein, the WG diet plus 0.8% L-lysine (LS), or the LS diet plus 0.5% L-carnitine (CS) for 30 days. On the 31st day the rats were given an oral dose of ethanol and blood-ethanol concentrations (BEC) were monitored for the next 8 hours. One week later the rats were given a second dose of ethanol and urine was collected until killed, 3 hours post-ethanol administration (PEA). Besides growth retardation and hypoproteinemia, BEC were significantly elevated in the WG group compared to the other group at hours 3-8 PEA. There were no significant differences in BEC between the LS and CS groups; however, their BEC were significantly higher than that of the NS group. The BEC were inversely related to liver alcohol dehydrogenase (ADH) activities which were significantly lower in WG, LS and CS groups than in the NS group. Plasma, liver and urine carnitine values were significantly higher in the CS group than in the NS, WG and LS groups, wherein the values were similar. It is concluded that the WG diet reduced ADH activity and attenuated ethanol metabolism without significantly altering blood, liver and urinary carnitines in the adult rat.

Gender differences in the effects of ethanol on C57BL/6 mice

The influence of gender on the stimulatory and depressant effects of ethanol was examined in C57BL/6 (C57) mice. In Experiment 1, locomotor activity was assessed in young (2-month-old) male and female mice injected intraperitoneally (IP) with stimulatory (1.5 g/kg) or depressant (2.5 g/kg) doses of ethanol. Both the stimulatory and the depressive effects of ethanol were greater in young male than female C57 mice, and the gender difference was unrelated to blood ethanol concentration (BEC). In Experiment 2, older (9-month-old) male and female mice were given ethanol (2.5 g/kg) either by IP injection or gavage to determine if the gender differences in BEC and ethanol effects observed in the first experiment depended upon the route of ethanol administration. In this experiment, ethanol reduced locomotor activity more in males than females whether given by gavage or IP injection, and the males had higher BECs than females at the time of testing. Thus, the differences in the behavioral effects of ethanol appeared to be related to BEC. The greater depressive effect of ethanol on older male mice in this experiment is consistent with an earlier report of prolonged ethanol-hypnosis in older male C57 mice. Therefore, differences in BEC could account for the gender differences in the behavioral effects of ethanol on older but not young mice. The gender difference in BEC of mice obtained in the present and earlier reports is opposite to that reported for humans. Although the present study does not clarify what accounts for this species difference, it eliminates the route of administration as a plausible explanation, and establishes that females were less affected than males to either the stimulatory or the depressive effects of ethanol.

Differences Between Multisite Postmortem Ethanol Concentrations as Related to Agonal Events

In a study of postmortem ethanol concentrations, blood was withdrawn from the right atrium, ascending aorta, and inferior vena cava. These samples, vitreous humor, and gastric fluid were analyzed in 307 autopsies, where a minimum blood ethanol concentration of 0.05% weight/volume (w/v) was present. Premortem, agonal, and postmortem events were reviewed in an attempt to account for differences in blood ethanol concentrations between sites. The agonal aspiration of vomitus having at least 0.80% w/v ethanol appears to be associated with an increase in aortic ethanol concentrations. We conclude that valid interpretation of postmortem ethanol concentrations must take into consideration the possible entry of ethanol into the pulmonary venous circulation via the respiratory system.

Chronic tolerance to ethanol in the N:NIH rat.

As the basis for selectively breeding rats from the N:NIH stock on the basis of differential development of tolerance to ethanol, chronic tolerance to the motor-disrupting effects of ethanol was examined. Male (n = 50) and female (n = 46) rats were administered 2.5 g/kg ethanol (i.p.) and the blood-ethanol concentration (BEC) at the time of regain of aerial righting reflex (RARR) was measured. The rats were then placed in inhalation chambers for 8 consecutive days and chronically exposed to ethanol. Thirty-two hours following the cessation of chronic ethanol exposure, the rats were again given a 2.5 g/kg dose of ethanol and the BEC at RARR was again measured. The amount of chronic ethanol tolerance developed, as measured by the difference in BEC at RARR prior to and after chronic ethanol administration, was widely and normally distributed for both male and female rats. Control rats, which did not receive chronic ethanol exposure between the two tests of RARR, did not show tolerance on this measure. A negative correlation (r = -0.46) was found between BEC at RARR prior to chronic ethanol treatment and the amount of chronic tolerance developed using the difference in BEC measure. This correlation suggested that the rats who were initially more sensitive to the effects of ethanol were more likely to display the greatest amount of chronic tolerance. However, using the residuals of the regression analysis of post-chronic ethanol BEC at RARR on prechronic BEC at RARR as an index of tolerance, this negative correlation was not found.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic functional ethanol tolerance in mice influenced by body temperature during acquisition

Previous studies have found that body temperature during intoxication influences brain sensitivity to ethanol with the sensitivity being less at cool than at warm body temperatures. If this effect of temperature reflects alterations in the acute membrane perturbing action of ethanol, as suggested by in vitro studies, then body temperature reduction (hypothermia) during tolerance acquisition should reduce the effectiveness of a given ethanol concentration and, in turn, should reduce the development of chronic functional ethanol tolerance. To test this hypothesis, adult drug-naive C57BL/6J mice were injected i.p. once daily for five days with 3.6 g/kg ethanol (20% w/v) and were exposed to 34°C or 25°C for five hours following injection. On day 6, both ethanol acquisition groups and naive mice were injected i.p. with 4.0 g/kg ethanol and exposed to 25°C. During acquisition, the group exposed to 34°C had significantly higher body temperatures than the mice exposed to 25°C, and there were no statistically significant differences in blood ethanol concentrations between treatment conditions. The extent of tolerance on day 6, measured by sleep-times and wake-up blood and brain ethanol concentrations versus naive mice, was significantly greater in the 34°C acquisition group than in the 25°C acquisition group. The results demonstrate that body temperature influences tolerance development in the manner predicted by membrane perturbation theories of anesthesia and adaptation based tolerance theories.

Biphasic effects of ethanol on open-field activity: Sensitivity and tolerance in C57BL/6N and DBA/2N mice.

Male C57BL/6N (C57) and DBA/2N (DBA) inbred mice were found to differ in open-field behavior after an acute ip injection of ethanol and in the development of tolerance to repeated injections. DBA mice showed only increased activity for 28 min after ethanol doses up to 2.67% g/kg when compared with saline-injected controls. Under the same conditions, C57 mice showed dose-related increases in activity during the first 4 min, followed by dose-related decreases in activity. The effects endured for at least 60 min after injection in both strains. In a third experiment, mice were injected daily with saline or 2.0 g/kg ethanol and tested on Days 1, 5, 9, and 13 for open-field activity. On the 17th day, all mice were tested after an ethanol injection. Neither strain showed tolerance to the activity-stimulating effect of ethanol. Some evidence for tolerance to the effect of ethanol to reduce activity in C57 mice was found. In a fourth experiment, twice-daily injections of ethanol for 10 days produced marked tolerance to the depressant effect of an injection on the 11th day in C57 mice, compared with those in a control group given ethanol for the first time on the 11th day. No tolerance to the stimulant effect of ethanol was seen in C57s. DBA mice were injected twice daily for 19 days but did not display tolerance when tested on Day 10 or on Day 20, Indeed, DBA mice chronically treated with ethanol exhibited more marked stimulation of activity after ethanol than mice treated chronically with saline. Differences in blood ethanol concentrations between the strains could not account for any of the observed differences. Implications for the genetic control of responses to ethanol are discussed.