Effect of omeprazole on gastric first-pass metabolism of ethanol

Some commonly used H2-receptor antagonists affect gastric first-pass metabolism of ethanol and lead to unexpectedly high blood alcohol concentrations after consumption of alcohol. To investigate whether omeprazole--a substituted benzimidazole recently approved for clinical use--has a similar harmful effect, we administered a moderate dose of ethanol (0.3 g/kg body wt) orally to seven normal volunteers before and after one week of omeprazole administration (20 mg daily). No significant effect of the drug was found on either mean peak blood alcohol concentrations or on areas under the blood alcohol curve; neither did these parameters differ significantly before or after an acute dose of omeprazole (13.2 mg/kg body wt) in rats, whether ethanol (0.25 g/kg body wt) was administered intragastrically or intravenously. In vitro, omeprazole in concentrations likely to occur in the gastric lumen (0.01-1.0 mM), did not affect gastric alcohol dehydrogenase activity of humans or rats. Thus omeprazole does not affect gastric first-pass metabolism of ethanol and can be considered as a safe choice for the treatment of patients who do not refrain from alcohol consumption during therapy.     

Ethanol and Natural Killer Cells. II. Stimulation of Human Natural Killer Activity by Ethanol In Vitro

A single ethanol ingestion of 1 g/kg by healthy individuals under controlled conditions does not inhibit and may stimulate fresh natural killer (NK) activity measured 16 hr later. However, ethanol inhibits fresh human NK activity when added to the lytic assay medium, as reported previously by other investigators. In contrast, using the same target (K562 erythroleukemia cells), peripheral blood mononu-clear cells cultured 3 days with 50 units/ml of interleukin-2 are no longer inhibited significantly by the same concentration of ethanol that inhibited the fresh cells by 80%. When freshly isolated peripheral blood mononuclear cells, monocyte-depleted lymphocytes, or partially purified NK cells are pre-exposed to ethanol in vitro for 1 to 7 days, washed, and assayed for lytic activity against K562, the lytic activity is increased compared with nonethanol-exposed cells incubated concurrently. This increase is not dependent on accessory cells, added cytokines, or cell growth, and seems to be an intrinsic response of the NK subset to ethanol exposure. The finding of NK stimulation by ethanol, considered together with the observation of NK cell loss in some chronic alcoholics, suggests that loss of NK activity in the chronic alcoholic may result from cell loss rather than direct ethanol inhibition of NK activity.     

Antimicrobial activity of Sapindus mukorossi and Rheum emodi extracts against H pylori： In vitro and in vivo studies

INTRODUCTION H pylori has infected more than half the population of the world. Most people are unaware that they are infected because they remain asymptomatic throughout life and survive without any harmful infection-related clinical sequelae. However, so…     

Effect of ethanol on thrombopoiesis

Chronic ethanol abuse causes thrombocytopenia but the underlying mechanism is unknown. To determine the target cells involved, we examined the effects of the drug in vitro on both megakaryocyte progenitor cells (CFU-Meg) and isolated, maturing megakaryocytes. In the presence of ethanol concentrations of 0.05-2.0 g/dl, megakaryocyte colony formation by mouse CFU-Meg in soft agar was normal. At 5 g/dl ethanol, colony formation was reduced by 50%; with 7 g/dl ethanol, no megakaryocyte colonies were formed. Acetaldehyde did not inhibit colony formation unless very high concentrations (100 mg/dl) were employed. Isolated guinea-pig megakaryocytes can maintain their viability and incorporate 3H-leucine into TCA-precipitable protein for at least 24 h. Incubation of these maturing megakaryocytes with ethanol did not affect their viability, but at concentrations greater than 120 mg/dl ethanol progressively inhibited protein synthesis. At 0.5 g/dl ethanol, protein synthesis was decreased by 23% while viability was still 93% of control. Like CFU-Meg, maturing megakaryocytes were resistant to the toxic effects of acetaldehyde. To determine the in vivo correlates of these results, guinea-pigs were fed 5 g/dl ethanol in a liquid diet. By 11 d, when blood ethanol levels were 20-150 mg/dl, platelet counts in the animals were reduced by 17-29%, while the number of marrow megakaryocytes was unaltered. These data indicate that the site of action of ethanol in suppressing thrombopoiesis is at the level of the maturing megakaryocyte.     

Increased blocking activity of combined tachykinin NK1- and NK2-receptor antagonists on hyperventilation-induced bronchoconstriction in the guinea pig

In vivo anesthetized guinea pigs were used to investigate the effect of tachykinin NK1- and NK2-receptor antagonists, as a single dose or in combination, against hyperventilation-induced bronchoconstriction (HIB). Guinea pigs were ventilated with a rodent ventilator and placed in a whole-body plethysmograph. Hyperventilation was induced by increasing the respiratory rate from 50 to 185 breaths/min for 10 min that produced a 177+/-45% increase in pulmonary resistance (RL) and a 68+/-7% decrease in lung compliance (CDyn). Intravenous (0.03-0.3mg/kg) and oral (0.3-10mg/kg) pretreatments with the tachykinin NK2-antagonist SR 48968 produced a dose-dependent inhibition of HIB whereas pretreatments with the tachykinin NK1-antagonist CP 99994 (1mg/kg intravenously and 30 mg/kg orally) had no effect on HIB. Intravenous and oral combinations of inactive and low doses of CP 99994 and SR 48968 produced a greater inhibition of HIB than SR 48968 alone. Also, the tachykinin NK3-antagonist SB 223412 (1-3mg/kg intravenously and 30 mg/kg orally) did not significantly reduce HIB although a trend was observed at the highest dose tested intravenously (3mg/kg). We conclude that HIB in the guinea pig is mostly mediated by the tachykinin NK2-receptors and to a lesser extent by the tachykinin NK1-receptors. Because the hyperventilation response in guinea pigs may be a surrogate for exercise-induced obstructive airway disease in human, these results suggest that combined use of dual tachykinin NK1- and NK2-receptor antagonists may provide greater benefit than treatment with single activity tachykinin NK-receptor antagonist.     

Human Gastric Alcohol Dehydrogenase: Its Inhibition by H2-Receptor Antagonists, and Its Effect on the Bioavailability of Ethanol

Two types of alcohol dehydrogenase isoenzymes (differing in their affinity for ethanol, sensitivity to 4-methylpyrazole, and electrophoretic migration) have been identified in the human stomach. At the high ethanol concentrations prevailing in the gastric lumen during alcohol consumption, the sum of their activities could account for significant oxidation of ethanol. In vitro, these activities were inhibited by cimetidine and ranitidine, but not by famotidine. In vivo, therapeutic doses of cimetidine (but not of famotidine) increased blood ethanol levels when ethanol was given orally, but not when it was given intravenously, indicating a significant contribution of the gastric ADH to the bioavailability and thereby the potential toxicity of ethanol.     

Effects of Ethanol on Cultured Fetal Serotonergic Neurons

In utero ethanol exposure impairs the development of several neurotransmitter systems, including the serotonergic system. However, at present the mechanism by which in utero ethanol exposure damages the developing brain is unknown. This research examined the possibility that ethanol directly impairs the development of serotonergic neurons. This hypothesis was assessed by examining the content of serotonin (5-HT), 5-HT uptake, and 5-HT immunopositive neurons in cultures of fetal rhombencephalic neurons that were exposed to ethanol for 4 days in vitro. In addition, the effects of in vitro ethanol exposure on protein and DNA content of cultured rhombencephalic neurons were determined.
These studies demonstrated that a 4-day exposure of cultured rhombencephatic neurons to 50 to 300 mg ethanol/dl did not affect 5-HT content, 5-HT uptake, or the proportion of 5-HT immunopositive neurons. In addition, this ethanol exposure had no significant effect on protein or DNA content. Additional studies, using a 4-day exposure to 450 mg ethanol/dl also did not detect significant differences in 5-HT uptake or in protein or DNA content.
The marked differences in the findings of the present in vitro and previous in vivo studies may be due to the fact that the ethanol exposure in vivo was longer than that in vitro, and included the period of early development of serotonergic neurons and their progenitors. Alternatively, the differences may be due to ethanol-associated alterations in maternal or fetal factors (e.g., hormones, amino acids, and growth factors) that are necessary for the normal development of the serotonergic system in vivo. Normal concentrations of such factors in the serum-containing media may have protected the cultured neurons from the damaging effects of ethanol.     

Ethanol Acutely Impairs the Renal Conservation of 5-Methyltetrahydrofolate in the Isolated Perfused Rat Kidney

The ethanol-induced increase in urinary folate excretion has been shown to decrease plasma folate levels and may contribute to the development of folate deficiency associated with alcoholism. The mechanism for this effect remains to be elucidated. The present studies were designed to examine the direct effect of ethanol on the renal handling of 5-methyltetrahydrofolate (5-CH₃-H₄PteGlu), the physiological folate. Rats were given four consecutive hourly doses of ethanol (1 g/kg) or isocaloric doses of glucose solution orally. This treatment generated an average plasma ethanol level of 305 mg/dl. Kidneys from male Sprague-Dawley rats were removed 5 hr after initial treatment and perfused in vitro to eliminate any extrarenal effects that could confound interpretation of results. Ethanol was not added to the perfusate. These treatments had no effect on 5-CH₃-H₄PteGlu conservation by the isolated perfused rat kidney in comparison to experiments in which the animal received no treatment. Ethanol was then added directly to the perfusate to generate average concentrations of 293 mg/dl. The in vitro addition of ethanol significantly decreased the percentage reabsorption and increased the fractional excretion of 5-CH₃H₄PteGlu in comparison to controls (kidneys perfused with or without an isocaloric dose of glucose). This effect did not become significant until the renal tissue was exposed to these levels of ethanol for 1 hr. These results indicate that ethanol directly impairs the renal conservation of 5-CH₃-H₄PteGlu.     

Prevention of graft rejection in allogeneic bone marrow transplantation: I. Preclinical studies with antithymocyte globulins

Heterologous horse antithymocyte globulins (ATG) were investigated in vitro as potential immunotherapeutic reagents in the prevention of bone marrow graft rejection by allogeneic recipients. Different lots and concentrations of ATG were evaluated for their ability to inactivate natural killer (NK) cells, IL-2 cultured 'augmented' NK cells, and/or cytotoxic T cells (CTL) using the 51Cr-release assay for measurement of cytotoxic activity. In vitro incubation of peripheral blood mononuclear cells (PBMC) with a prototype non-myelotoxic ATG (ATGP12) at 0.1 mg/ml (a concentration which can be achieved with an i.v. infusion of approximately 30 mg ATG/kg daily) variously inhibited NK activity (0-100%); whereas treatment with the same concentration of ATGP12 and autologous human complement completely inhibited NK, as well as 'augmented' NK function from all normal individuals tested. Incubation of T cytotoxic effector cells with ATGP12 alone also significantly abrogated primed T cell cytotoxicity. These studies demonstrate that lots of ATG can be easily prescreened and titered in vitro in order to identify immunosuppressive reagents capable of inhibiting the MHC restricted and non-restricted cytotoxic cells, which can survive chemotherapy and radiation, and may play a critical role in resistance to engraftment of T cell-depleted marrow.     

Ciprofloxacin decreases the rate of ethanol elimination in humans

BACKGROUND: Extrahepatic ethanol metabolism is postulated to take place via microbial oxidation in the colon, mediated by aerobic and facultative anaerobic bacteria. AIMS: To evaluate the role of microbial ethanol oxidation in the total elimination rate of ethanol in humans by reducing gut flora with ciprofloxacin. METHODS: Ethanol was administered intravenously at the beginning and end of a one week period to eight male volunteers. Between ethanol doses volunteers received 750 mg ciprofloxacin twice daily. RESULTS: A highly significant (p=0.001) reduction in the ethanol elimination rate (EER) was detected after ciprofloxacin medication. Mean (SEM) EER was 107.0 (5.3) and 96.9 (4.8) mg/kg/h before and after ciprofloxacin, respectively. Faecal Enterobacteriaceae and Enterococcus sp. were totally absent after medication, and faecal acetaldehyde production capacity was significantly (p<0.05) decreased from 0.91 (0.15) to 0.39 (0.08) nmol/min/mg protein. Mean faecal alcohol dehydrogenase (ADH) activity was significantly (p<0. 05) decreased after medication, but ciprofloxacin did not inhibit human hepatic ADH activity in vitro. CONCLUSIONS: Ciprofloxacin treatment decreased the ethanol elimination rate by 9.4%, with a concomitant decrease in intestinal aerobic and facultative anaerobic bacteria, faecal ADH activity, and acetaldehyde production. As ciprofloxacin has no effect on liver blood flow, hepatic ADH activity, or cytochrome CYP2E1 activity, these effects are probably caused by the reduction in intestinal flora.     

Immune enhancement effect of an herb complex extract through the activation of natural killer cells and the regulation of cytokine levels in a cyclophosphamide-induced immunosuppression rat model

Objective: To investigate the effects of a herb complex extract(HCE) prepared from Cornus officinalis Sieb. Et Zucc., Eriobotrya japonica Lindley, and olive leaves on immune response of mouse spleen NK cells in vitro and in vivo analysis. Methods: The activity of natural killer(NK) cells was measured in splenocytes and YAC-1 cells. Mice were immunosuppressed using cyclophosphamide(5 mg/kg body weight). Three different doses of HCE(200, 400, and 800 mg/kg body weight) and red ginseng extract(800 mg/kg body weight) which was used as standard immunomodulatory herb were administered orally for 4 weeks. The body weight, dietary, water intake, organs(liver, thymus, and spleen) weight, completed blood count, and cytokines(tumor necrosis factor alpha, interferon gamma, and interleukin-2) production was measured. Results: At the maximum concentration of HCE, the activity of NK cells was increased by 48.5%. HCE increased liver, spleen, and thymus weights without altering numbers of white blood cells, lymphocytes, and neutrophils in a cyclophosphamide-induced immunosuppression rat model. However, HCE recovered the inhibited cytokine expression; HCE(800 mg/kg) increased cytokines levels. The results indicate the immune enhancement potential of this HCE. Conclusion: The HCE enhances immunity by increasing NK cell activity, regulating cytokine levels, and maintaining spleen weight. Therefore, it may be used as a potential immunity enhancer.     

In vivo effect of endothelin-1 on plasma calcium and parathyroid hormone concentrations

We have previously reported an in vitro inhibitory effect of endothelin-1 (ET-1) on parathyroid hormone (PTH) secretion. In the present experiment, ET-1 was infused into rabbits to study the in vivo effect of ET-1 on the changes in calcium, magnesium, PTH and calcitonin concentrations. Femoral arteries and veins of anesthetized male rabbits were cannulated to monitor vital signs, blood sampling and infusion of the agents being studied. Infusion of ET-1 (1, 5, 10 and 20 ng/kg per min) induced a dose-dependent decline in plasma ionized calcium concentrations from 6.68+/-0.26 to 5.50+/-0.46 mg/dl (P<0.05) and a decrease in calcitonin concentrations from 48.6+/-6.5 to 32.5+/-4.7 pg/ml. PTH concentrations increased from 58.3+/-10.2 to 159.4+/-22.1 pg/ml. In a separate experiment, calcium gluconate solution was simultaneously infused to keep calcium concentrations steady, thereby proving a calcium 'clamp'. In normal calcium concentration, ET-1 infusion gradually decreased PTH concentrations from 71.4+/-8.6 to 38.0+/-6.2 pg/ml. We further infused sodium citrate solution to decrease the calcium concentration (2.0 mg/dl less) and calcium gluconate solution was infused to keep calcium concentrations steadily less than normal. PTH concentrations were initially stimulated by the induction of hypocalcemia (68.1+/-11.2 to 135.6+/-8.5 pg/ml), but decreased by ET-1 infusion (135.6+/-8.5 to 85.1+/-15.2 pg/ml). Plasma magnesium concentrations did not change significantly throughout the entire study and calcitonin concentrations were not significantly changed during the calcium clamp studies. Serum phosphate and 1,25-(OH)(2) vitamin D(3) concentrations were also measured, but they also did not change significantly. In conclusion, ET-1 exhibited an in vivo acute hypocalcemic action, independent of calcitonin. It also directly decreased PTH secretion if serum calcium concentrations were kept steady. The above findings are consistent with the results of our previous in vitro experiment.     

Ethanol induces Fas/Apo [apoptosis]-1 mRNA and cell suicide in the developing cerebral cortex

INTRODUCTION: Animal studies modeling fetal alcohol syndrome have demonstrated that developmental exposure to alcohol is associated with decreased brain weight and significant neuronal loss in multiple regions of the developing brain. Our previous data suggest that the Fas/Apo [apoptosis]-1 receptor is transiently expressed in the developing cerebral cortex during the peak period of naturally occurring apoptotic cell death and maximum sensitivity to alcohol. Therefore, we hypothesized that ethanol increases the expression of suicide receptors such as Fas/Apo-1 in the developing fetal cerebral cortex and leads to an upregulation or extension of the normal period of apoptosis and consequent disorganization of the neural circuitry. METHODS: Ethanol was administered in one of four doses (120, 320, 630, and 950 mg/dl) to organotypic explant cultures of the developing cerebral cortex established from postnatal day 2 rats and maintained for 6 days in vitro. The number of cells expressing Fas/Apo-1 receptor mRNA was counted. Apoptosis was measured by the use of two independent assays; a cell death enzyme-linked immunosorbent assay for DNA fragmentation and flow cytometric analysis of Annexin-V binding to phosphatidylserine externalized to the outer leaflet of the plasma membrane. Necrosis was also estimated by two independent measures, the amount of lactate dehydrogenase released into culture medium and flow cytometric analysis of cells that were positive for both Annexin-V and propidium iodide. RESULTS: A significantly larger number of developing cortical cells expressed Fas/Apo-1 mRNA at the lower doses (120 and 320 mg/dl) than at the higher doses (630 and 950 mg/dl). Furthermore, ethanol induced apoptosis in a dose-related manner, with peak apoptosis observed at a dose of 630 mg/dl in the case of DNA fragmentation and at 630 and 950 mg/dl in the case of phosphatidylserine translocation to the outer leaflet of the plasma membrane. Ethanol did not induce necrosis at any of the administered doses of ethanol. CONCLUSIONS: Our data suggest that ethanol induces a susceptibility to apoptotic signals at low doses by upregulating the expression of mRNAs for cytotoxic receptors such as Fas/Apo-1 in the developing cerebral cortex. However, ethanol itself specifically induces apoptosis in the developing cerebral cortex only at higher doses.     

Neuroanatomic and Neurochemical Abnormalities in Non-human Primate Infants Exposed to Weekly Doses of Ethanol during Gestation

Ethanol was orally administered once per week to 54 gravid pigtailed macaques ( Macaca nemestrina ) in doses of 0.0, 0.3, 0.6, 1.2, 1.8, 2.5 or 4.1 gm/kg from the 1st week in gestation or in doses of 2.5, 3.3 or 4.1 gm/kg from the 5th week. Mean maternal peak plasma ethanol concentrations (MPPEC's) ranged from 24 ± 6 mg/dl at the 0.3 g/kg dose to 549 ± 71 mg/dl at the 4.1 g/kg dose. Thirty-three live born infants were assessed for abnormalities of physical and behavioral development. Ocular pathology, neuropathologic and neurochemical assessments were done on 31 animals at 6 months postnatal age. Microphthalmia was noted in three of the 26 animals exposed to ethanol. Retinal ganglion cell loss was significantly associated with intra-uterine ethanol exposure. Microphthalmia and retinal ganglion cell loss was observed in both the delayed and full-gestational exposed animals. No structural anomalies were found in the brains via gross inspection or light microscopy. Chemical abnormalities in the striatal nuclei were identified. Striatal dopamine concentrations increased with increasing MPPEC exposure (0–249 mg/dl) among animals exposed weekly to ethanol throughout gestation. Striatal dopamine concentrations decreased with increasing MPPEC exposure (260–540 mg/dl) among animals whose weekly exposure to ethanol was delayed until the 5th week of gestation. The same pattern of association was also noted between MPPEC and ultrastructural alterations in the caudate nucleus. The extent of ultrastructural alterations increased with increasing MPPEC among the fullgestational exposed animals and decreased with increasing MPPEC among the delayed-dose animals.     

Severe methanol poisoning. Application of a pharmacokinetic model for ethanol therapy and hemodialysis

Two patients with extremely high blood methanol concentrations (260 and 282 mg/dl) were successfully treated using pharmacokinetic dosing of ethanol, hemodialysis and supportive measures. Both patients recovered completely without residual ophthalmologic deficits. Early hemodialysis and inhibition of methanol metabolism with effective ethanol concentrations were attributed to the patients' full recovery. Methanol elimination was enhanced by hemodialysis as evidenced by a decrease in half-life from eight to two and a half hours. Methanol dialysance was 98 ml/min. A dosage regimen for ethanol was devised, utilizing dose-dependent pharmacokinetic parameters and the ethanol dialysance (100 to 120 ml/min) from these two patients. An ethanol loading dose of 0.6 g/kg should be administered to an adult with an acute methanol ingestion. This dose will produce a blood ethanol concentration of approximately 100 mg/dl which can be maintained by an ethanol infusion of 66 mg/kg/hour for nondrinkers to 154 mg/kg/hour for chronic ethanol drinkers. Hemodialysis should be initiated if the blood methanol concentration is greater than 50 mg/dl. If hemodialysis is initiated, the ethanol infusion should be increased by 7.2 g/hour.     

Ethanol-Induced Changes in Peripheral Blood and Splenic Natural Killer Cells

Previous work demonstrated that splenic natural killer (NK) cell cytolytic activity was suppressed in ethanol-consuming mice within 1 week and for as long as 10 weeks concurrent with ethanol intake. However, it is unknown if suppression of NK cell activity with ethanol consumption results from regional losses in NK cells. The present experiments were designed to examine the effect of ethanol on the percentage and total number of NK cells in the spleen and blood. Data indicate that, after 4 weeks of ethanol intake, NK cell activity of peripheral blood lymphocytes was also suppressed (50% of controls). With short-term (2-week) exposure, the percentage of NK cells in the blood and the spleen remained relatively constant. In the spleen, changes in the number of NK cells reflected generalized fluctuations in lymphocyte numbers rather than variation in the percentage of NK cells. NK cells were most sensitive to the effects of ethanol during long-term (8-week) ethanol intake, as demonstrated by significant reductions in the total percentage of NK 1.1⁺ cells in the blood, and the LGL-1⁺ subset in the blood and spleen.
These results provide insight into the mechanism of NK modulation by ethanol. Because NK cells were not selectively depleted after 2–4 weeks of ethanol intake, loss of cytolytically active NK cells cannot explain the suppression of in vitro cytolytic activity of cells from ethanol-consuming mice. However, with prolonged ethanol intake (8 weeks), the depletion of NK cells, specifically the LGL-1⁺ subset, may contribute to the overall suppression of NK cell cytolytic function.     

Third trimester binge ethanol exposure results in fetal hypercapnea and acidemia but not hypoxemia in pregnant sheep

BACKGROUND: The mechanisms by which maternal ethanol abuse during pregnancy causes neurodevelopmental injury in the fetus are not well understood. The purpose of this study was to use a chronically instrumented fetal sheep model system to determine if a binge pattern of ethanol exposure administered throughout the third trimester reduced fetal arterial partial pressure of oxygen (PaO2); a positive finding would support the hypothesis that fetal hypoxemia may play a role in mediating ethanol-related birth defects. METHODS: Pregnant ewes received saline or 0.75, 1.25, 1.5, or 1.75 g/kg of ethanol intravenously over 1 hr beginning on day 109 of gestation (term = 145 days) for 3 consecutive days per week followed by 4 days without exposure. The fetuses were surgically instrumented on day 113, and experiments were performed on days 118 or 132, the 6th and the 12th ethanol exposure, respectively. RESULTS: Ethanol infusions resulted in peak blood ethanol concentrations of 80.8 +/- 6.5, 182.5 +/- 13.5, 224.4 +/- 13.9, and 260.6 +/- 20.0 mg/dl +/- SEM (maternal) and 70.0 +/- 5.9, 149.7 +/- 9.0, 216.9 +/- 14.0, and 233.3 +/- 19.8 mg/dl +/- SEM (fetal) in response to the 0.75, 1.25, 1.5, and 1.75 g/kg doses, respectively. Maternal and fetal heart rate and maternal blood pressure increased whereas fetal blood pressure decreased in a dose-dependent manner in response to ethanol infusions. Maternal and fetal arterial pH decreased and arterial partial pressures of carbon dioxide increased in response to ethanol infusions. Maternal PaO2 decreased whereas fetal PaO2 did not change in response to ethanol infusions. CONCLUSIONS: A binge ethanol exposure paradigm, three consecutive days per week throughout the third trimester at ethanol doses that created blood ethanol concentrations commonly achieved by human ethanol abusers, resulted in changes in maternal and fetal heart rate, changes in blood pressure, hypercapnea, acidemia, and maternal, but not fetal, hypoxemia. We conclude that in an ovine model system, ethanol doses that create blood ethanol concentrations as high as 260 mg/dl do not result in fetal hypoxemia. Remaining issues to address with this model system are whether neurodevelopmental injuries that are associated with maternal ethanol abuse are mediated by a reduction in fetal cerebral blood flow, fetal hypercapnea, or acidemia.     

In vivo and in vitro effects of low molecular weight heparan sulphate on the human fibrinolytic enzyme system

The aim of this study was to evaluate the effects of a preparation of low molecular weight heparan sulphate (LMW-HS) on the fibrinolytic system. Twenty-five healthy volunteers received LMW-HS by mouth in three separate experiments. In the first experiment, 10 volunteers received either 80 mg LMW-HS or placebo in a single-blind cross-over study; blood samples were taken before and 1, 2, 3 and 6 h after treatment. LMW-HS caused an increase in global fibrinolysis, the effect being greatest after 2-3 h and disappearing by 6 h. However, neither plasminogen activator activity nor tissue-type plasminogen activator (tPA) antigen levels were changed. In the second experiment, daily doses of 80 mg LMW-HS were administered to 10 volunteers for 7 days; this regimen did not produce a statistically significant increase in fibrinolytic activity for the whole group although some individuals did respond markedly. In the third experiment, 160 mg LMW-HS administered to five volunteers did not affect ADP- and collagen-induced platelet aggregation. In vitro, LMW-HS added to plasma at concentrations of 20 and 30 micrograms/ml, brought about a significant increase in apparent plasminogen activator activity. These results suggest that the increased fibrinolytic activity seen after LMW-HS is due to the recruitment of additional amounts of tPA in the ex vivo test system. LMW-HS had no effect on plasminogen activator inhibitor.     

Effect of Ethanol on Kupffer Cell Function

Kupffer cells are resident macrophages in the liver and are important in both local and systemic immune responses. We evaluated the ability of Kupffer cells in vitro to respond to immune stimulation after both acute exposure to ethanol and after long-term ethanol consumption of ethanol. Triplets of female Wistar rats were fed a liquid diet containing 0, 12, or 36% ethanol isocalorically for 112 days. When killed, the Kupffer cells were isolated by collagenase perfusion and adhered to plastic 24-well plates. They were then stimulated with 10 μg/ml lipopolysaccharide for 4.5 hr. Synthesis of procoagulant activity (PCA) and tumor necrosis factor (TNF), expressions of macrophage response to immune stimuli, were measured by a one-step clotting assay and L929 cytotoxicity assay, respectively. Within each of the 10 triplets, PCA and TNF levels were normalized and expressed as a percentage of the zero ethanol isocaloric control rat. The high ethanol group had significantly lower baseline and stimulated PCA and TNF levels than the low ethanol group. For evaluation of the effect of acute exposure to ethanol, Kupffer cells were stimulated with lipopolysaccharide and varying concentrations (0–400 mg/dl) of ethanol. Cells were incubated for 4.5 hr and assayed for PCA and TNF activity. There was dose-dependent inhibition of PCA and TNF, with increasing concentrations of ethanol. These results indicate that whereas exposure to high levels of ethanol depresses Kupffer cell function, lower levels may be immunostimulatory.     

Electrophysiological Effects of Ethanol on Monoaminergic Neurons: An in Vivo and in Vitro Study

Monoaminergic neurons have been shown to play a role in both the intoxicating and chronic effects of ethanol. We present here the results of a study about the acute effects of ethanol on serotonergic raphe nucleus, noradrenergic locus coeruleus, and dopaminergic ventral tegmental area. These nuclei were investigated electrophysiologically by recording the spontaneous firing rate of single neurons using glass microelectrodes, both in vivo in chloral hydrate anesthetized rats and in vitro in brain slices. Ethanol was perfused intravenously at a rate ranging from 0.2 mg/kg/min to 0.2 g/kg/min in vivo, and at concentrations between 10(-8) M and 1 M in vitro. We observed that each monoaminergic nucleus had its own pattern of responses to acute ethanol perfusion, and that high and low concentrations have different actions, suggesting a biphasic effect. For example, in slices, ethanol concentrations higher than 10 mM induce an excitation in most raphe and ventral tegmental area neurons, and an inhibition of firing in locus coeruleus neurons. The results were comparable in the in vivo model, but much more heterogenous. We conclude that the effect of ethanol on the monoaminergic neurons is specific of the type of neuron, and that a biphasic effect is commonly found.