geranylgeranylacetone and Shock

The present study was performed to determine whether oral pretreatment with geranylgeranylacetone (GGA) inhibits proinflammatory cytokine liberation and nitric oxide (NO) production in lipopolysaccharide (LPS)-treated rats and protects rats against death from LPS-induced endotoxin shock, and whether such protection by GGA is related to heat shock protein (HSP) 70 induction in multiple organs of rats. GGA (200 mg/kg) was given orally to rats. LPS (20 mg/kg) was administered intraperitoneally 4, 8, 16, or 24 h after GGA administration. The survival of rats was monitored over 24 h after LPS administration. GGA treatment at 8 or 16 h before LPS dramatically improved the survival rate of LPS-treated rats. Plasma levels of proinflammatory cytokines (tumor necrosis factor-alpha and interleukin-6) and NO 6 h after LPS administration in these GGA-pretreated rats were less than one-half of those in rats treated with LPS alone. A GGA challenge 8 or 16 h before LPS administration enhanced HSP70 expression in rat organs after LPS. Treatment with GGA 8 h before LPS minimized hepatic and renal damage. Furthermore, the protective effect of GGA on mortality in LPS-treated rats was inhibited with quercetin, known as an HSP70 inhibitor. These results suggest that oral administration of GGA at an optimal time before LPS injection induces and enhances HSP70 expression in several organs, inhibits proinflammatory cytokine and NO production, and prevents organ damage, resulting in an improved survival rate.

Topics: Administration, Oral; Animals; Anti-Ulcer Agents; Blotting, Western; Disease Models, Animal; Diterpenes; Dose-Response Relationship, Drug; Endotoxins; HSP70 Heat-Shock Proteins; Inflammation; Interleukin-6; Kidney; Lipopolysaccharides; Male; Nitric Oxide; Rats; Rats, Sprague-Dawley; Shock; Time Factors; Treatment Outcome; Tumor Necrosis Factor-alpha

The effects of teprenone (6,10,14,18-tetramethyl-5,9,13, 17-nonadecatetraen-2-one) on changes in gastric mucosal blood flow, adenosine triphosphate (ATP) content, and incidence of histologic lesions were evaluated in rat gastric mucosa after hemorrhage and retransfusion.. Teprenone (100 mg/kg) was administered orally once a day for 3 consecutive days. On the 3rd day hemorrhage was induced, withdrawn blood (retransfusion) was returned, and the above variables were determined.. Teprenone significantly inhibited the decreases in blood flow and index of mucosal oxygen saturation (ISO2) during hemorrhage in the corpus and antral mucosa. However, no effect of teprenone was observed on systemic blood pressure and ATP levels after hemorrhage and retransfusion. Teprenone significantly (p < 0.05) decreased both the incidence of ischemic lesions and the increase in the severity of lesions after retransfusion in both mucosal regions.. From these results, it is concluded that the protective effect of teprenone on blood flow was partly responsible for its inhibitory effect on the incidence of lesions in the rat stomach in this hypovolemic shock model, although the former effect might be not a direct effect on systemic vascular tone.

Topics: Adenosine Triphosphate; Animals; Anti-Ulcer Agents; Blood Transfusion, Autologous; Disease Models, Animal; Diterpenes; Energy Metabolism; Gastric Mucosa; Gastrointestinal Hemorrhage; Hemodynamics; Male; Rats; Rats, Wistar; Shock