Mechanism of salutary effects of androstenediol on hepatic function after trauma-hemorrhage: role of endothelial and inducible nitric oxide synthase

Dehydroepiandrosterone: Molecular mechanisms and therapeutic implications in osteoarthritis

Dehydroepiandrosterone (DHEA), a 19-carbon steroid hormone primarily synthesized in the adrenal gland, exerts a chondroprotective effect against osteoarthritis (OA) and has been considered an effective candidate of disease-modifying OA drugs (DMOADs) that slow disease progression. We and others previously demonstrated that DHEA exerted a beneficial effect on osteoarthritic cartilage by positively modulating the balance between anabolic and catabolic factors (e.g., MMPs/TIMP-1, ADAMTS/TIMP-3 and cysteine proteinases/cystatin C), inhibiting catabolic signaling pathways (e.g., Wnt/β-catenin), and suppressing proinflammatory cytokines-mediated low-grade synovial inflammation (e.g., IL-1β). However, the full picture of the pharmacological molecular mechanism(s) underlying the activity of DHEA against OA is still incomplete, and a comprehensive and up-to-date review article in this field is unavailable. In this review, recent findings (apart from the well documented pathogenesis of OA) regarding disease-related mechanisms involving low grade synovial inflammation, cartilage matrix stiffness, chondrocyte autophagy and the roles of a variety of catabolic cellular signaling pathways are discussed. Moreover, the possible relationship between these disease-related mechanisms and DHEA action is discussed. Emerging evidence from in vivo and in vitro studies were scrutinized and are concisely presented to demonstrate the investigational and putative mechanisms underlying the anti-OA potential of DHEA.

Dehydroepiandrosterone sulfate and dehydroepiandrosterone sulfate/cortisol ratio in cirrhotic patients with septic shock: another sign of hepatoadrenal syndrome?

BACKGROUND

Cirrhotic patients are susceptible to sepsis and critical illness-related corticosteroid insufficiency (CIRCI). Dehydroepiandrosterone sulfate (DHEAS) is a corticotropin-dependent adrenal androgen, which has immunostimulating and antiglucocorticoid effects. Considering the synchronized synthesis of cortisol and DHEAS and their opposing effects to each other, investigators have proposed measuring these two hormones as a ratio. Severe sepsis has been associated with low DHEAS, especially relative to high cortisol. Despite growing interest in the role of adrenal androgen replacement in critical illness, there have been no data about DHEAS and the DHEAS/cortisol ratio in patients with liver cirrhosis. We studied whether low concentrations of DHEAS and decreased DHEAS/cortisol ratio are associated with poor outcome in patients with liver cirrhosis and septic shock.

METHODS

We recruited 46 cirrhotic patients with septic shock, and 46 noncirrhotic counterparts matched by age and sex. We evaluated adrenal function using the short corticotropin stimulation test and analyzed the relation between DHEAS and cortisol.

RESULTS

While the nonsurvivors in the cirrhotic group had significantly lower baseline DHEAS, lower baseline DHEAS/cortisol ratio, and reduced increments of both DHEAS and cortisol upon corticotropin stimulation, the survivors had lower baseline cortisol. Cirrhotic patients with lower DHEAS/cortisol ratio (<1.50) had higher levels of interleukin-6 and tumor necrosis factor alpha, higher Sequential Organ Failure Assessment scores, and higher rates of CIRCI and hospital mortality. Using the area under the receiver operating characteristic (AUROC) curve, both DHEAS and the DHEAS/cortisol ratio demonstrated a good discriminative power for predicting hospital survival (AUROC 0.807 and 0.925 respectively). The cirrhotic group had lower DHEAS and DHEAS/cortisol ratio but higher rates of CIRCI and hospital mortality, compared to the noncirrhotic group.

CONCLUSIONS

There is dissociation between cortisol (increased) and DHEAS (decreased) in those cirrhotic patients who succumb to septic shock. Low DHEAS/cortisol ratios are associated with more severe diseases, inflammation, and CIRCI and can serve as a prognostic marker. More investigations are needed to evaluate the role of adrenal androgen in this clinical setting.

Helping prometheus: liver protection in acute hemorrhagic shock

Acute hemorrhagic hypovolemic shock is caused by a significant high blood loss and leads to hemodynamic instability. The decrease in intravascular volume results in cellular hypoxia and finally in damage to organs such as the liver and the kidney. The liver plays a decisive role in the development or prevention of multiple organ failure after hemorrhagic shock. Despite the large number of experimental studies, the knowledge of pathophysiological mechanisms in the liver after hemorrhagic shock is incomplete. The aim of this mini review was to provide an overview of the pathophysiological changes in liver function after acute hemorrhagic shock and to address treatment options to improve liver perfusion.

Exacerbation of Mild Hypoxia on Acute Radiation Syndrome and Subsequent Mortality

Mild hypoxia induced by 20% hemorrhage results in increases in few cytokine concentrations and sclerostin levels in blood, but shows no changes in bone formation, bone marrow cellularity, and gastrointestinal (GI) integrity and no systemic bacterial infection as well as no subsequent mortality. On the other hand, severe hypoxia induced by 40% hemorrhage causes significant increases in most cytokine concentrations, GI injury, lung injury, systemic bacterial infection, cellular ATP reduction and subsequent mortality. The severe hypoxia drastically damages GI and lung morphology, elevates cytokine concentrations in blood and increases inducible nitric oxide synthase (iNOS) expression in cells that is mediated by transcription factors NF-κB/NF-IL6, subsequently producing free radicals that disrupt mitochondria. ATP depletion, p53 phosphorylation, and caspase-3 activation are found, suggesting cell apoptosis. As a result, mortality occurs. However, when mild hypoxia follows ionizing radiation, the mild hypoxia significantly enhances radiation-induced mortality and acute radiation syndrome, including injury of bone marrow, GI, kidney, and lung. The synergism also occurs at the molecular level, resulting in alteration of microRNAs, amplification of iNOS expression, cytokine increases, sepsis, and ATP depletion. This is the first demonstration of synergistic effects between mild hypoxia and ionizing radiation.

Dehydroepiandrosterone modulates the inflammatory response in a bilateral femoral shaft fracture model

Background

Dehydroepiandrosterone (DHEA) has been shown to have immunomodulatory effects after hemorrhage and sepsis. The present study analyzes whether DHEA is also involved in the mediation of inflammatory stimuli induced by bilateral femoral shaft fracture.

Methods

Male C57/BL6 mice (6 per group) were subjected to closed bilateral femoral shaft fracture with intramedullary nailing followed by administration of either 25 mg/kg/24 h DHEA diluted in saline with 0.1% ethanol or saline with 0.1% ethanol. The sham group was treated by isolated intramedullary nailing without fracture. Animals were sacrificed after 6, 24, or 72 h. Serum TNFα, IL-1β, IL-6, IL-10, MCP-1, and KC concentrations were measured by Bio-Plex Pro^Tm analysis. Acute pulmonary inflammation was assessed by histology, pulmonary myeloperoxidase (MPO) activity, and pulmonary IL-6 concentration.

Results

DHEA was associated with a decrease in the systemic inflammatory response induced by bilateral femoral fracture, especially systemic IL-6 (322.2 vs. 62.5 pg/mL; P = 0.01), IL-1β (1,422.6 vs. 754.1 pg/mL; P = 0.05), and MCP-1 (219.4 vs. 44.1 pg/mL; P >0.01) levels. No changes in pulmonary inflammation were measured.

Conclusion

We conclude that DHEA may be a treatment option to reduce systemic inflammation following musculoskeletal injuries although the pulmonary inflammatory reaction was not affected.

Oxidative metabolism of dehydroepiandrosterone (DHEA) and biologically active oxygenated metabolites of DHEA and epiandrosterone (EpiA)--recent reports

Dehydroepiandrosterone (DHEA) is a multifunctional steroid with a broad range of biological effects in humans and animals. DHEA can be converted to multiple oxygenated metabolites in the brain and peripheral tissues. The mechanisms by which DHEA exerts its effects are not well understood. However, evidence that the effects of DHEA are mediated by its oxygenated metabolites has accumulated. This paper will review the panel of oxygenated DHEA metabolites (7, 16 and 17-hydroxylated derivatives) including a number of 5α-androstane derivatives, such as epiandrosterone (EpiA) metabolites. The most important aspects of the oxidative metabolism of DHEA in the liver, intestine and brain are described. Then, this article reviews the reported biological effects of oxygenated DHEA metabolites from recent findings with a specific focus on cancer, inflammatory and immune processes, osteoporosis, thermogenesis, adipogenesis, the cardiovascular system, the brain and the estrogen and androgen receptors.

ERK and not p38 pathway is required for IL-12 restoration of T cell IL-2 and IFN-gamma in a rodent model of alcohol intoxication and burn injury

Previous studies from our laboratory have shown that acute alcohol/ethanol (EtOH) intoxication combined with burn injury suppresses T cell IL-2 and IFN-gamma production by inhibiting p38 and ERK activation. Because IL-12 plays a major role in Th1 differentiation and IFN-gamma production, we examined whether diminished IL-2 and IFN-gamma production after EtOH plus burn injury resulted from a decrease in IL-12. Furthermore, we investigated whether IL-12 utilizes the p38/ERK pathway to modulate T cell IL-2 and IFN-gamma production after EtOH and burn injury. Male rats ( approximately 250 g) were gavaged with 5 ml of 20% EtOH 4 h before approximately 12.5% total body surface area burn or sham injury. Rats were sacrificed on day 1 after injury, and mesenteric lymph node T cells were isolated. T cells were stimulated with anti-CD3 in the absence or presence of rIL-12 (10 ng/ml) for 5 min and lysed. Lysates were analyzed for p38/ERK protein and phosphorylation levels using specific Abs and Western blot. In some experiments, T cells were cultured for 48 h with or without the inhibitors of p38 (10 microM SB203580/SB202190) or ERK (50 microM PD98059) to delineate the role of p38 and ERK in IL-12-mediated restoration of IL-2 and IFN-gamma. Our findings indicate that IL-12 normalizes both p38 and ERK activation in T cells, but the results obtained using p38 and ERK inhibitors indicate that the restoration of ERK plays a predominant role in IL-12-mediated restoration of T cell IL-2 and IFN-gamma production after EtOH and burn injury.

Flutamide protects against trauma-hemorrhage-induced liver injury via attenuation of the inflammatory response, oxidative stress, and apopotosis

Although studies have shown that administration of testosterone receptor antagonist, flutamide, following trauma-hemorrhage, improves hepatic, cardiovascular, and immune functions, the precise cellular/molecular mechanisms responsible for producing these salutary effects remain largely unknown. To study this, male C3H/HeN mice were subjected to a midline laparotomy and hemorrhagic shock (35+/-5 mmHg for approximately 90 min), followed by resuscitation with Ringer lactate. Flutamide (25 mg/kg) or vehicle was administered subcutaneously at the onset of resuscitation, and animals were killed 2 h thereafter. Hepatic injury was assessed by plasma alpha-glutathione S-transferase concentration, liver myeloperoxidase activity, and nitrotyrosine formation. Hepatic malondialdehyde and 4-hydroxyalkenals (lipid peroxidation indicators), cellular DNA fragmentation, and the expression of inducible nitric oxide synthase and hypoxia-inducible factor-1alpha were also evaluated. Cytokines (TNF-alpha, IL-6) and chemokines (keratinocyte-derived chemokine and monocyte chemoattractant protein-1) levels were determined by cytometric bead array. The results indicate that flutamide administration after trauma-hemorrhage reduced liver injury, which was associated with decreased levels of alpha-glutathione S-transferase, myeloperoxidase activity, nitrotyrosine formation, lipid peroxidation, and cytokines/chemokines (systemic, liver tissue, and intracellular cytokines/chemokines). Cellular apoptosis, hepatocyte hypoxia-inducible factor-1alpha, and inducible nitric oxide synthase expression were also decreased under such conditions. Thus administration of flutamide following trauma-hemorrhage protects against liver injury via reduced inflammation, cellular oxidative stress, and apoptosis.

Estrogen: a novel therapeutic adjunct for the treatment of trauma-hemorrhage-induced immunological alterations

Trauma-hemorrhage leads to prolonged immune suppression, sepsis, and multiple organ failure. The condition affects all compartments of the immune system, and extensive studies have been carried out elucidating the immunological events following trauma-hemorrhage. The immune alteration observed following trauma-hemorrhage is gender dependent in both animal models and humans, though some studies in humans are contradictory. Within 30 min after trauma-hemorrhage, splenic and peritoneal macrophages, as well as T-cell function, are depressed in male animals, but not in proestrus females. Studies have also shown that the mortality [corrected] rate and the induction of subsequent sepsis following trauma-hemorrhage are significantly higher in males and ovariectomized females compared with proestrus females. These and other investigations show that sex hormones form the basis of this gender dichotomy, and administration of estrogen can ameliorate the immune depression and increase the survival rate after trauma-hemorrhage. This review specifically elaborates the studies carried out thus far demonstrating immunological alteration after trauma-hemorrhage and its modulation by estrogen. Also, estrogen was shown to produce its salutary effects through nuclear as well as extranuclear receptors. Estrogen rapidly activates several protein kinases and phosphatases, as well as the release of calcium in different cell types. The results of the studies exemplify the promise of estrogen as a therapeutic adjunct in treating adverse pathophysiological conditions following trauma-hemorrhage.

The role of estrogen receptor subtypes in ameliorating hepatic injury following trauma-hemorrhage

BACKGROUND/AIMS

The aim of this study was to determine which of the estrogen receptor (ER) subtypes plays a predominant role in ameliorating hepatic damage following trauma-hemorrhage.

METHODS

Adult male rats were subjected to hemorrhagic shock (40 mmHg for 90 min) and resuscitation. ER-alpha agonist (PPT) or ER-beta agonist (DPN) was administered during resuscitation; rats were sacrificed 24h thereafter.

RESULTS

PPT or DPN decreased elevated plasma alpha-glutathione S-transferase levels; however, PPT was more effective. PPT or DPN increased hepatic heat shock protein 32 (Hsp32) mRNA/protein expressions above levels observed after trauma-hemorrhage. PPT reduced hepatic NF-kappaB and AP-1 activity and iNOS expression. Although DPN reduced hepatic NF-kappaB activity, AP-1 activity remained higher than in shams; hepatic iNOS induction remained elevated. PPT/DPN reduced nitrate/nitrite production and iNOS mRNA in Kupffer cells following trauma-hemorrhage; however, these levels in DPN-treated animals remained higher than sham.

CONCLUSIONS

Although both PPT and DPN decreased hepatic injury following trauma-hemorrhage, ER-alpha agonist PPT appears to be more effective in downregulating NF-kappaB and AP-1 activity, and iNOS induction. Thus, ER-alpha appears to play a predominant role in mediating the salutary effects of E2 in ameliorating hepatic damage following trauma-hemorrhage.

Geldanamycin inhibits hemorrhage-induced increases in caspase-3 activity: role of inducible nitric oxide synthase

Hemorrhage has been shown to increase inducible nitric oxide synthase (iNOS) and deplete ATP levels in tissues and geldanamycin limits both processes. Moreover, it is evident that inhibition of iNOS reduces caspase-3 and increases survival. Thus we sought to identify the molecular events responsible for the beneficial effect of geldanamycin. Hemorrhage in mice significantly increased caspase-3 activity and protein while treatment with geldanamycin significantly limited these increases. Similarly, geldanamycin inhibited increases in proteins forming the apoptosome (a complex of caspase-9, cytochrome c, and Apaf-1). Modulation of the expression of iNOS by iNOS gene transfection or siRNA treatment demonstrated that the level of iNOS correlates with caspase-3 activity. Our data indicate that geldanamycin limits caspase-3 expression and protects from organ injury by suppressing iNOS expression and apoptosome formation. Geldanamycin, therefore, may prove useful as an adjuvant in fluids used to treat patients suffering blood loss.

Flutamide attenuates pro-inflammatory cytokine production and hepatic injury following trauma-hemorrhage via estrogen receptor-related pathway

OBJECTIVE

To determine the mechanism by which flutamide administration following trauma-hemorrhage (T-H) decreases cytokine production and hepatic injury under those conditions.

SUMMARY BACKGROUND DATA

Although studies have demonstrated that flutamide administration following T-H improves hepatic and immune functions, the mechanism by which flutamide produces the salutary effects remains unknown.

METHODS

Male Sprague-Dawley rats underwent a 5-cm laparotomy and hemorrhagic shock (40 mm Hg for approximately 90 minutes), followed by resuscitation with 4 times the shed blood volume in the form of Ringer's lactate. Flutamide (25 mg/kg body weight, sc) was administered at the middle of resuscitation and animals were killed 2 hours thereafter. To block estrogen receptor (ER), ER antagonist ICI 182,780 was administrated with flutamide.

RESULTS

Hepatic injury, myeloperoxidase activity, nuclear factor-kappaB (NF-kappaB) DNA binding activity and protein expression of intercellular adhesion molecule-1, and cytokine-induced neutrophil chemoattractant (CINC-1 and CINC-3) markedly increased following T-H. Hepatic mRNA and plasma IL-6 levels were also elevated following T-H. The alterations in these parameters induced by T-H were significantly attenuated by flutamide administration. The decreased plasma estradiol levels following T-H were restored to sham levels in the flutamide-treated T-H animals. Coadministration of ICI 182,780 prevented those salutary effects of flutamide administration on pro-inflammatory responses and hepatic injury following T-H.

CONCLUSION

These findings suggest that the reduction in the production of pro-inflammatory mediators and hepatic injury produced by flutamide administration following T-H is likely due to the down-regulation in hepatic NF-kappaB DNA binding activity. Moreover, the salutary effects of flutamide administration appear to be mediated at least in part via ER-related pathway.

Effect of DHEA on the Hemodynamic Response to Resuscitation in a Porcine Model of Hemorrhagic Shock

BACKGROUND

Hemorrhagic shock is a major cause of death from trauma. Pharmacologic treatment has not been satisfactory. The objective of this study was to use a porcine model of hemorrhagic shock and resuscitation to access the hemodynamic effects of dehydroepiandrosterone (DHEA), an adrenal steroid hormone reported to improve cardiac function in patients.

METHODS

Hemorrhagic shock was produced in 20- to 30-kg male Yorkshire pigs anesthetized with 2% isoflurane by withdrawing blood through a carotid cannula to a mean arterial pressure (MAP) of 40 to 45 mm Hg and maintaining that level for 60 minutes by further removals of blood. Resuscitation was with 21 mL/kg Ringer's lactate (LR), with (n = 6) or without (n = 6) DHEA (4 mg/kg) dissolved in propylene glycol. The animals were killed after 7 days. Continuous cardiac output (CCO) was recorded using a modified Swan-Ganz catheter system. MAP, heart rate (HR), central venous pressure (CVP), and pulmonary arterial pressure (PAP) were measured every 5 minutes until 60 minutes postresuscitation. From MAP, CCO, HR, and CVP, we calculated total peripheral resistance (TPR), stroke volume (SV), and left ventricular stroke work (SW).

RESULTS

The MAP, CCO, SV, and SW decreased significantly during hemorrhagic shock, and then gradually increased to baseline levels during and 1 hour after resuscitation. The TPR was increased during hemorrhagic shock, and then gradually decreased to baseline levels during and after resuscitation. DHEA administration was associated with no significant improvement.

CONCLUSION

DHEA when added to standard fluid resuscitation showed no added benefit as resumed by the hemodynamic response.

Androstenetriol improves survival in a rodent model of traumatic shock

Trauma results in activation of the hypothalamic-pituitary-adrenal axis to mediate a cascade of neurohormonal changes as a defensive mechanism. Its prolongation, however, leads to a hypermetabolic, hypoperfused, and immunosuppressed state, setting the stage for subsequent sepsis and organ failure. Androstenetriol (5-androstene-3beta, 7beta, 17betatriol - AET), a metabolite of dehydroepiandrosterone, up-regulates the host immune response markedly, prevents immune suppression and controls inflammation, leading to improved survival after lethal infections by several diverse pathogens and lethal radiation. Such actions may be useful in improving survival from traumatic shock.

HYPOTHESIS

The neurosteroid AET will increase survival following traumatic shock.

METHODS

A combat relevant model of traumatic shock was used. Male Sprague-Dawley rats were anesthetized, catheterized and subjected to soft tissue injury (laparotomy). Animals were allowed to regain consciousness over the next 0.5 h and then bled 40% of their blood volume over 15 min. Forty-five minutes after the onset of hemorrhage animals were randomized to receive either a single subcutaneous dose of AET (40 mg/kg, sc) or vehicle (methylcellulose). Volume resuscitation consisted of l-lactated Ringer's (three times the shed blood volume), followed by packed red blood cells (one-third shed red cell volume). Animals were observed for three days.

RESULTS

A total of 24 animals were studied. Of the 12 animals randomized to receive AET, all (100%) survived compared to 9 of 12 animals (75%) randomized to receive the vehicle (p < 0.05).

CONCLUSION

AET significantly improved survival when administered subcutaneously in a single dose in this rodent model of traumatic shock. Further survival and mechanism studies are warranted.

Androstenediol inhibits the trauma-hemorrhage-induced increase in caspase-3 by downregulating the inducible nitric oxide synthase pathway

Soft tissue trauma and hemorrhage (T-H) diminishes various aspects of liver function, while it increases hepatic nitrate/nitrite, inducible nitric oxide synthase (iNOS), and endothelin-1 levels. Treatment with androstenediol (AED) inhibits the T-H-induced alterations of the above parameters. We sought to identify the molecular events underlying the beneficial effect of AED. Exposure of rats to T-H significantly increased the caspase-3 activity and protein, whereas treatment with AED significantly limited these increases. AED treatment also suppressed the T-H-induced increase in iNOS by effectively altering the levels of key transcription factors involved in the regulation of iNOS expression. Immunoprecipitation and immunoblotting analyses indicate that T-H increased apoptosome formation, and AED treatment significantly decreased it. Modulating the iNOS protein by transfecting cells with iNOS gene or small interfering RNA further confirmed the correlation between iNOS and caspase-3. Our data indicate that AED limits caspase-3 expression by suppressing the expression of transcription factors involved in the production of iNOS, resulting in decreased apoptosome. AED can potentially be a useful adjuvant for limiting liver apoptosis following T-H shock.

A role of PPAR-gamma in androstenediol-mediated salutary effects on cardiac function following trauma-hemorrhage

OBJECTIVE

To examine the mechanism by which androstenediol improves cardiac function following trauma-hemorrhage (T-H).

SUMMARY BACKGROUND DATA

Androstenediol administration improves cardiovascular function and attenuates proinflammatory cytokine production following T-H. Activation of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) has been shown to be protective following ischemic conditions. We hypothesized that PPAR-gamma activation plays a role in the androstenediol-mediated salutary effects on cardiac function following T-H.

METHODS

Male rats underwent laparotomy and hemorrhagic shock (40 mm Hg for 90 minutes), followed by resuscitation with 4 times the shed blood volume in the form of Ringer's lactate. Androstenediol (1 mg/kg body weight, i.v.) was administrated at the end of resuscitation. In a separate group of animals, a PPAR-gamma antagonist (GW9662) was administered simultaneously with androstenediol and animals were killed at 5 hours thereafter.

RESULTS

A decrease in cardiac function and an increase in IL-6 and iNOS gene expression were observed following T-H. Androstenediol treatment normalized cardiac function, increased PPAR-gamma DNA binding activity, attenuated IL-6 and iNOS gene expressions, and reduced plasma IL-6. Plasma 15-deoxy-Delta12, 14-prostaglandin J2 (PGJ2, an endogenous PPAR-gamma agonist) levels were also increased in androstenediol-treated T-H rats, but these levels were lower than those observed in shams. Coadministration of PPAR-gamma antagonist along with androstenediol, however, prevented the androstenediol-mediated reduction in cardiac iNOS and IL-6 expressions and abolished the improvements in cardiac function.

CONCLUSION

The androstenediol-mediated salutary effects on cardiac function following T-H appear to be mediated at least in part via PPAR-gamma activation, which down-regulates IL-6 and iNOS gene expression in the heart.

Androstenediol administration after trauma-hemorrhage attenuates inflammatory response, reduces organ damage, and improves survival following sepsis

Although androstenediol (adiol or 5-androstene-3beta,17beta-diol), a metabolite of dehydroepiandrosterone (DHEA), has protective effects following trauma-hemorrhage (T-H), it remains unknown whether administration of adiol has any salutary effects on the inflammatory response and outcome following a combined insult of T-H and sepsis. Male rats underwent T-H shock [mean arterial pressure (MAP) 40 mmHg for 90 min] followed by resuscitation. Adiol (1 mg/kg body wt) or vehicle was administered at the end of resuscitation. Sepsis was induced by cecal ligation and puncture (CLP) at 20 h after T-H or sham operation. Five hours after CLP, plasma and tissue samples were analyzed for cytokines (IL-6 and IL-10), MPO, neutrophil chemotactic factor (CINC-3), and liver injury (alanine aminotransferase and lactate dehydrogenase). In another group of rats, the gangrenous cecum was removed at 10 h after CLP, the cavity was irrigated with warm saline and closed in layers, and mortality was recorded over 10 days. T-H followed by CLP produced a significant elevation in plasma IL-6 and IL-10 levels, enhanced neutrophil cell activation, and resulted in liver injury. Adiol administration prevented the increase in cytokine production, neutrophil cell activation, and attenuated liver injury. Moreover, rats subjected to the combined insult, receiving vehicle or adiol, had a 50% and 6% mortality, respectively. Since adiol administration suppresses proinflammatory cytokines, reduces liver damage, and decreases mortality after the combined insult of T-H and sepsis, this agent appears to be a novel adjunct to fluid resuscitation for decreasing T-H-induced septic complications and mortality.

Salutary effects of androstenediol on hepatic function after trauma-hemorrhage are mediated via peroxisome proliferators-activated receptor gamma

BACKGROUND

A recent study suggested that administration of androstenediol (Adiol) after trauma-hemorrhage (T-H) improves hepatic functions; however, the mechanism responsible for the salutary effect of Adiol remains unknown. Although studies indicate similarities and association between the anti-inflammatory properties of Adiol and peroxisome proliferator-activated receptor gamma (PPARgamma), whether the salutary effects of Adiol are mediated via upregulation of PPARgamma remains unclear.

METHODS

Male Sprague-Dawley rats underwent laparotomy and approximately 90 minutes of hemorrhagic shock (40 mm Hg), followed by resuscitation with 4 times the shed blood volume in the form of Ringer's lactate. Adiol (1 mg per kilogram of body weight, iv) was administered at the end of resuscitation. An additional group of rats were treated with PPARgamma antagonist (GW9662, 1 mg/kg ip) along with Adiol and the rats were sacrificed 5 hours thereafter.

RESULTS

Hepatic functions were markedly depressed and plasma tumor necrosis factor-alpha, C-reactive protein and endothelin-1 were markedly increased after T-H. DNA-binding activity of nuclear factor kappa B and AP-1, and gene expressions of inducible nitric oxide synthase and endothelin-1 in the liver also increased significantly. These parameters were attenuated by Adiol treatment. These effects were accompanied an increased DNA-binding activity of PPARgamma in T-H-Adiol-treated rats. Treatment of rats with GW9662 prevented the salutary effects of Adiol after T-H.

CONCLUSIONS

Since blockade of PPARgamma prevented the salutary effects of Adiol on hepatic functions and proinflammatory factors, this finding suggests that Adiol mediated its salutary effects after T-H via the PPARgamma-related pathways.