Immune response modulation in acutely ethanol-intoxicated, acutely diabetic male and female rats.

We examined how acute diabetes mellitus and acute ethanol intoxication modulate factors that mediate immune responses as a basis for explaining the increased susceptibility to infection in these two conditions. Our working hypothesis is that ethanol intoxication in diabetes compromises host defense mechanisms to a greater extent than observed in each condition alone. Male and female rats were made diabetic with streptozotocin (65 mg/kg, i.p.). Forty-eight hours after administration of streptozotocin, rats either received no treatment (control group) or were treated with (1) ethanol (bolus injection of 1.75 g/kg, followed by a 3-h infusion at the rate of 300 mg/kg/h), (2) lipopolysaccharide [(LPS); 0.9 mg/kg], or (3) a combination of LPS+ethanol. At the end of 3 h, rats were killed, and the livers were digested by perfusion with collagenase-containing Hanks' balanced salt solution to isolate hepatocytes and Kupffer cells. To measure chemokine generation, hepatocytes (2.5x10(5) cells per well) and Kupffer cells (1x10(6) cells per well) were cultured for 20 h, and the supernatant was used to measure cytokine-induced neutrophil chemoattractant (CINC) and regulated on activation, normal T-cell expressed and secreted (RANTES) chemokines. Phagocytosis by Kupffer cells was measured by flow cytometry and expressed as mean channel fluorescence intensity (MCF). Induction of diabetes as well as treatment of nondiabetic rats with LPS, ethanol, or LPS+ethanol caused depression of MCF values of Kupffer cells. However, treatment of the diabetic male and female rats with LPS and LPS+ethanol increased the MCF values relative to those of Kupffer cells obtained from untreated diabetic rats, but administration of ethanol to diabetic rats did not have a similar effect. The induction of diabetes caused an increase in CINC generation by Kupffer cells obtained from male rats, but not from female rats. This diabetes-induced elevation of chemoattractant factor was decreased when diabetic animals were treated with LPS, ethanol, or LPS+ethanol, and the sex difference was obliterated. Thus, the induction of diabetes as well as treatment with LPS, ethanol, or LPS+ethanol in nondiabetic rats depressed the phagocytic capability of Kupffer cells, whereas the presence of endotoxemia (administration of the endotoxin LPS) or administration of LPS+ethanol reversed the diabetic effect, but ethanol intoxication did not. These findings seem to indicate a persistence of depression of host defense capacity in the ethanol-intoxicated diabetic condition. This is further reinforced by the depression of the diabetes-induced enhancement of chemotaxis when the diabetic rats became intoxicated.

Sex differences in the modulation by ethanol of lung chemotaxis.

We studied the influence of sex on the modulation by acute ethanol intoxication of lung polymorphonuclear leukocyte (PMN) recruitment, production of chemotactic factors, and nuclear factor kappa-B (NF-kappa B) activation in alveolar macrophages (AMs) of rats receiving an intrapulmonary challenge with endotoxin (ET). Male and female Charles River rats were given an intratracheal ET challenge [100 micro g in phosphate-buffered saline (PBS)], followed by an intravenous infusion of ethanol or saline for 2.5 h. At that time, bronchoalveolar lavage (BAL) fluid was obtained, and AMs and recruited PMNs were isolated. Acute ethanol treatment [primed 2.5-h intravenous infusion of ethanol, priming dose of 0.87 ml per 100 grams of body weight of 20% (vol./vol.) ethanol, followed by a continuous infusion of 20% ethanol at 0.15 ml per 100 grams of body weight per hour] suppressed ET-induced lung PMN recruitment equally in female and male rats. However, cytokine-induced neutrophil chemoattractant (CINC) and macrophage inflammatory protein-2 (MIP-2) in BAL fluid were suppressed only in female rats. Polymorphonuclear leukocytes of untreated female rats responded to MIP-2 and formyl-methionyl-leucyl-phenylalanine (fMLP) with lower chemotactic activity than did PMNs of male rats. Activation of NF-kappa B in AMs of female rats treated with ET or with ET plus ethanol was less than that in male rats, supporting the suggestion of transcriptional regulation of chemoattractant production, leading to reduced PMN recruitment. Because excessive PMN recruitment with subsequent release of granular contents is associated with tissue damage, these results indicate a potential protective mechanism against pulmonary damage in female rats.

Ethanol and LPS modulate NF-kappaB activation, inducible NO synthase and COX-2 gene expression in rat liver cells in vivo.

Ethanol and LPS are immunomodulators, whose actions are associated with the activation of the transcription factor, NF-kappaB, that mediates the expression of a number of rapid response genes involved in the whole body inflammatory response to injury, including transcriptional regulation of iNOS and COX-2. We investigated modulation by acute ethanol (EtOH) intoxication, LPS and LPS tolerance of NF-kappaB activation in hepatocytes, Kupffer cells and sinusoidal endothelial cells (SEC), concurrent regulation of iNOS and COX-2 gene expression and the influence of gender on these mechanisms. In vivo EtOH alone or with LPS significantly activates NF-kappaB in Kupffer cells and SEC. iNOS gene expression in these cells is modulated by LPS+EtOH in a gender- dependent manner. Acute EtOH administration enhanced iNOS mRNA in hepatocytes and Kupffer cells.LPS tolerance decreased LPS-induced NF-kappaB activation in Kupffer cells, but markedly raised iNOS mRNA in all three cell types with gender differences (females being higher). In LPS tolerant rats EtOH decreased elevated iNOS mRNA in all cells studied. LPS tolerance significantly reduced LPS-induced COX-2 mRNA in SEC, but only moderately in Kupffer cells of females, and not at all in males. Since NO is a known scavenger of superoxide and therefore protective against oxidative injury associated with LPS and acute EtOH intoxication, the gender differential effect of LPS+EtOH on iNOS gene expression (reduced only in females) may contribute to the greater susceptibility of females to alcoholic liver disease. Suppression of COX-2 gene expression in SEC may cause detrimental effects in the hepatic microcirculation, associated with cirrhosis.