Premium
Acute Ethanol Intoxication Prevents Lipopolysaccharide‐Induced Down Regulation of Protein Kinase C in Rat Kupffer Cells
Author(s) -
D'Souza Nympha B.,
Bautista Abraham P.,
Lang Charles H.,
Spitzer John J.
Publication year - 1992
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/j.1530-0277.1992.tb00637.x
Subject(s) - lipopolysaccharide , protein kinase c , kupffer cell , endocrinology , chemistry , medicine , immune system , pharmacology , biology , biochemistry , immunology , kinase
Protein kinase (PK) C has been implicated in a number of cellular events, many of which are also known to be affected by ethanol (ETOH). ETOH intoxication is also known to impair immune function, thereby increasing the host's susceptibility to infection. The purpose of this study was to assess the effect of acute ETOH intoxication on PKC activity and its intracellular distribution in nonparenchymal liver cells following an E. coli lipopolysaccharide (LPS) challenge. The liver was chosen for the study because it is the primary site both for metabolism of ETOH and detoxification of gut derived bacterial products. Catheterized conscious rats were administered saline or ETOH (175 mg/100 g body weight as a bolus followed by a continuous, 7 hr infusion of 28 mg/100 body weight/hr). LPS was injected intravenously (100 μg/100 g body weight) 3 hr before the end of the saline or ETOH infusion. Kupffer and endothelial cells were isolated by collagenase‐pronase digestion followed by centrifugal elutriation. PKC was assayed after extraction with digitonin containing buffer and partial purification on DE‐52 cellulose minicolumns. LPS decreased PKC activity by 69% from control values. Although ETOH infusion alone did not affect PKC activity in Kupffer cells, it completely abrogated the LPS effect. A similar trend was observed for the endothelial cells. No significant differences were observed between groups with respect to the intracellular distribution of PKC. The down‐regulation of PKC by LPS may represent a mechanism of functional adaptation of the immunocompetent cells to one of the cytokines, i.e., TNF, whose receptors are down regulated by activation of PKC. By counteracting such an action, ETOH would impair the adequate responsiveness of various cells to their own secretory products and to mediators from other cells, thereby, compromising the immune defense capacity of the body.