The regulatory role of vasoactive intestinal peptide in lacrimal gland ductal fluid secretion: A new piece of the puzzle in tear production.

Purpose: Vasoactive intestinal peptide (VIP) is an important regulator of lacrimal gland (LG) function although the effect of VIP on ductal fluid secretion is unknown. Therefore, the aim of the present study was to investigate the role of VIP in the regulation of fluid secretion of isolated LG ducts and to analyze the underlying intracellular mechanisms. Methods: LGs from wild-type (WT) and cystic fibrosis transmembrane conductance regulator (CFTR) knockout (KO) mice were used. Immunofluorescence was applied to confirm the presence of VIP receptors termed VPAC1 and VPAC2 in LG duct cells. Ductal fluid secretion evoked by VIP (100 nM) was measured in isolated ducts using videomicroscopy. Intracellular Ca2+ signaling underlying VIP stimulation was investigated with microfluorometry. Results: VIP stimulation resulted in a robust and continuous fluid secretory response in isolated duct segments originated from WT mice. In contrast, CFTR KO ducts exhibited only a weak pulse-like secretion. A small but statistically significant increase was detected in the intracellular Ca2+ level [Ca2+]i during VIP stimulation in the WT and in CFTR KO ducts. VIP-evoked changes in [Ca2+]i did not differ considerably between the WT and CFTR KO ducts. Conclusions: These results suggest the importance of VIP in the regulation of ductal fluid secretion and the determining role of the adenylyl cyclase-cAMP-CFTR route in this process.

The Role of Aquaporin 4 in Lacrimal Gland Ductal Fluid Secretion in Mice.

Purpose: Earlier reports highlighted the predominant presence of aquaporin 4 (AQP4) in the duct cells of rabbit lacrimal glands (LGs). Whereas significant alterations in AQP4 mRNA levels have been observed in experimental dry eye and during pregnancy, the impact of AQP4 in LG ductal fluid production remains unclear. In our recent work, the role of AQP4 in LG ductal fluid secretion was investigated utilizing wild type (WT) and AQP4 knock out (KO) mice. Methods: Tear production was assessed in both WT and KO animals. Immunostaining was used to identify AQP4 protein. Duct segments were harvested from LGs of WT and KO mice. Fluid secretion and filtration permeability (Pf) were quantified using video-microscopy. Ductal tear production, elicited by a cell-permeable cAMP analogue (8-bromo cAMP), carbachol, vasoactive intestinal peptide (VIP), and phenylephrine (PHE), were assessed in both WT and KO ducts. Results: A higher expression of AQP4 protein was noted in the duct cells from WT mice when compared to acinar cells. Pf did not show notable alterations between WT and AQP4 KO ducts. Carbachol elicited comparable secretory responses in ducts from both WT and KO animals. However, 8-bromo cAMP, VIP, and PHE stimulation resulted in decreased secretion in ducts from AQP4 KO LGs. Conclusions: Our findings underscore the functional relevance of AQP4 in the fluid production of mouse LG ducts. AQP4 seems to play different roles in fluid secretions elicited by different secretagogues. Specifically, cAMP-mediated, and adrenergic agonist-related secretions were reduced in AQP4 KO ducts.

Alpha-Adrenergic Agonists Stimulate Fluid Secretion in Lacrimal Gland Ducts.

Purpose: The role of adrenergic innervation in the regulation of lacrimal gland (LG) ductal fluid secretion is unknown. The Aim of the present study was to investigate the effect of adrenergic stimulation on fluid secretion in isolated LG duct segments and to study the underlying intracellular mechanisms. Methods: Fluid secretion of isolated mouse LG ducts was measured using video-microscopy. Effect of various adrenergic agonists (norepinephrine, phenylephrine, and isoproterenol) on fluid secretion as well as inhibitory effects of specific antagonists on adrenergic agonist-stimulated secretory response were analyzed. Changes in intracellular Ca2+ level [Ca2+i] were investigated with microfluorometry. Results: Both norepinephrine and phenylephrine initiated a rapid and robust fluid secretory response, whereas isoproterenol did not cause any secretion. Phenylephrine-induced secretion was completely blocked by α1D-adrenergic receptor blocker BMY-7378. The endothelial nitric oxide synthase (eNOS) inhibitor L-NAME or guanylyl cyclase inhibitor ODQ reduced but not completely abolished the phenylephrine-induced fluid secretion, whereas co-administration of Ca2+-chelator BAPTA-AM resulted in a complete blockade. Phenylephrine stimulation induced a small, but statistically significant elevation in [\(Ca_i^{2 + }\)]. Conclusions: Our results prove the direct role of α1-adrenergic stimulation on LG ductal fluid secretion. Lack of isoproterenol-induced fluid secretory response suggests the absence of ß-receptor mediated pathway in mouse LG ducts. Complete blockade of phenylephrine-induced fluid secretion by BMY-7378 and predominant inhibition of the secretory response either by L-NAME or ODQ suggest that α-adrenergic agonists use the NO/cGMP pathway through α1D receptor. Ca2+ signaling independent from NO/cGMP pathway may also play an at least partial role in α-adrenergic induced ductal fluid secretion.

Identification, Structural and Functional Characterization of Dormancy Regulator Genes in Apricot (Prunus armeniaca L.).

In the present study, we identified and characterized the apricot (Prunus armeniaca L.) homologs of three dormancy-related genes, namely the ParCBF1 (C-repeat binding factor), ParDAM5 (dormancy-associated MADS-BOX) and ParDAM6 genes. All highly conserved structural motifs and the 3D model of the DNA-binding domain indicate an unimpaired DNA-binding ability of ParCBF1. A phylogenetic analysis showed that ParCBF1 was most likely homologous to Prunus mume and Prunus dulcis CBF1. ParDAM5 also contained all characteristic domains of the type II (MIKCC) subfamily of MADS-box transcription factors. The homology modeling of protein domains and a phylogenetic analysis of ParDAM5 suggest its functional integrity. The amino acid positions or small motifs that are diagnostic characteristics of DAM5 and DAM6 were determined. For ParDAM6, only a small part of the cDNA was sequenced, which was sufficient for the quantification of gene expression. The expression of ParCBF1 showed close association with decreasing ambient temperatures in autumn and winter. The expression levels of ParDAM5 and ParDAM6 changed according to CBF1 expression rates and the fulfillment of cultivar chilling requirements (CR). The concomitant decrease of gene expression with endodormancy release is consistent with a role of ParDAM5 and ParDAM6 genes in dormancy induction and maintenance. Cultivars with higher CR and delayed flowering time showed higher expression levels of ParDAM5 and ParDAM6 toward the end of endodormancy. Differences in the timing of anther developmental stages between early- and late-flowering cultivars and two dormant seasons confirmed the genetically and environmentally controlled mechanisms of dormancy release in apricot generative buds. These results support that the newly identified apricot gene homologs have a crucial role in dormancy-associated physiological mechanisms.

Novel Insight Into the Role of CFTR in Lacrimal Gland Duct Function in Mice.

Purpose: The role of cystic fibrosis transmembrane conductance regulator (CFTR) in lacrimal gland (LG) function has only recently received some attention, mainly from our group. In the present study, we investigated the potential changes of LG pathology, tear secretion, ocular surface integrity, and fluid secretion in isolated LG ducts from CFTR knockout (KO) mice. Methods: Tear production and ocular surface integrity were investigated in anesthetized wild-type (WT) and KO mice using cotton threads and fluorescein staining, respectively. Immunofluorescence was used to localize CFTR protein in the LGs. Ductal fluid secretions evoked by forskolin (10 µM); cell-permeable cAMP analogue (8-bromo cAMP, 100 µM); or carbachol (100 µM) were measured in isolated LG ducts using video-microscopy. Intracellular Ca2+ homeostasis underlying carbachol stimulation was investigated with microfluorometry. Results: Significant decrease in tear secretion and impaired ocular surface integrity were observed in KO mice. Immunofluorescence demonstrated the predominant presence of CFTR protein in the apical membranes of the duct cells from WT mice. Continuous fluid secretion was evoked by forskolin and 8-bromo cAMP in LG ducts from WT mice, while no secretory response was observed in ducts from KO mice. Carbachol caused similar secretory responses in ducts from WT and KO animals without significant differences in cytosolic Ca2+ signaling. Conclusions: Our results suggest the important role of CFTR in LG ductal secretion and in the maintenance of ocular surface integrity, suggesting that CFTR may be a promising target of novel therapeutic approaches in the treatment of dry eye.

Skeletal muscles, heart, and lung are the main sources of oxygen radicals in old rats.

The aim of this study was to compare rat tissues with respect to their reactive oxygen and nitrogen species (RONS) generating activities as a function of age. We quantified the RONS generation in vivo in young (6 months) and in old (30 months) male Sprague-Dawley rats using the recently developed spin trap 1-hydroxy-3-carboxy-pyrrolidine, applied intravenously. This spin trap reacts with superoxide radical and peroxynitrite yielding a stable spin adduct which is detectable by means of electron paramagnetic resonance (EPR) spectroscopy in frozen tissues. In old rats RONS generation was significantly increased compared to their young counterparts in the following order: blood

Mechanisms of vasodilatation induced by nitrite instillation in intestinal lumen: possible role of hemoglobin.

It has been shown that nitrite can be reduced to nitric oxide (NO) in intestine and a number of other tissues and released into the blood to form nitrosylhemoglobin (NO-Hb), existing in an equilibrium with S-nitrosohemoglobin. The latter has been suggested to be an NO transporter to distant organs. The aim of this study was to define the pathway of nitrite reduction to form NO in intestinal wall and to estimate whether this pathway has an effect on peripheral circulation. We have shown that in rat intestine at pH 7.0 70% of nitrite is converted to NO in mitochondria. At pH 6.0, nonenzymatic nitrite reduction becomes as efficient as the mitochondrial pathway. To prove whether the NO formed from nitrite in intestine can induce vasodilatation, sodium nitrite was instilled into intestinal lumen and the concentration of NO formed and diffused into the blood was followed by measuring of NO-Hb complex formation. We found that the concentration of NO-Hb gradually increases with the increase of nitrite concentration in intestinal lumen. However, it was not always accompanied by a decrease in systemic blood pressure. Blood pressure dropped down only after NO-Hb reached a threshold concentration of approximately 10 microM. These data show that NO-Hb cannot provide enough NO for vasodilatation if the concentration of NO bound to Hb is < 10 microM. The exact mechanism underlying vasodilatation observed when the concentration of NO-bound Hb was > 10 microM is, however, not clear yet and requires further studies.

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.

Epr analysis reveals three tissues responding to endotoxin by increased formation of reactive oxygen and nitrogen species.

The excessive formation of reactive oxygen and nitrogen species (RONS) in tissue has been implicated in the development of various diseases. In this study we adopted ex vivo low temperature EPR spectroscopy combined with spin trapping technique to measure local RONS levels in frozen tissue samples. CP-H (1-hydroxy-3-carboxy-pyrrolidine), a new nontoxic spin probe, was used to analyze RONS in vivo. In addition, nitrosyl complexes of hemoglobin were determined to trace nitric oxide released into blood. By this technique we found that RONS formation in tissue of control animals increased in the following order: liver < heart < brain < cerebellum < lung < muscle < blood < ileum < kidney < duodenum < jejunum. We also found that endotoxin challenge, which represents the most common model of septic shock, increased the formation of RONS in rat liver, heart, lung, and blood, but decreased RONS formation in jejunum. We did not find changes in RONS levels in other parts of gut, brain, skeletal muscles, and kidney. Scavenging of RONS by CP-H was accompanied by an increase in blood pressure, indicating that LPS-induced vasodilatation may be due to RONS, but not due to nitric oxide. Experiments with tissue homogenates incubated in vitro with CP-H showed that ONOO(-) and O(2)(*)(-), as well as other not identified RONS, are detectable by CP-H in tissue. In summary, low-temperature EPR combined with CP-H infusion allowed detection of local RONS formation in tissues. Increased formation of RONS in response to endotoxin challenge is organ specific.

Dynamic in vivo observation of villus microcirculation during small bowel autotransplantation: effects of endothelin-A receptor inhibition.

BACKGROUND: The aims of this study were to characterize the structural and microcirculatory changes in single intestinal villi during ischemia and reperfusion and determine the site of action of endothelin (ET)-A receptor inhibition during compromised mucosal perfusion. METHODS: Small bowel autotransplantation was performed in anesthetized dogs. One group was treated with the ET-A receptor antagonist ETR-p1/fl peptide. The epithelial thickness and villus microcirculatory parameters were observed by orthogonal polarization spectral imaging; the leukocyte-endothelial cell interactions were quantified with fluorescence videomicroscopy. RESULTS: Sixty-minute cold ischemia and 240-min reperfusion induced a decrease in villus functional capillary density and leukocyte-endothelial cell interactions. The epithelial layer was gradually removed, but denuded villi were not observed. ET-A receptor inhibition reduced the leukocyte adherence and attenuated epithelial exfoliation and the decrease in villus functional capillary density. CONCLUSIONS: ET-A receptor activation mediates microvascular dysfunction through precapillary blockades and leukocyte-endothelial cell interactions after cold ischemia and reperfusion in the canine small bowel.

Hemorrhagic shock induces an S 100 B increase associated with shock severity.

S 100 B is a glial marker of cerebral Injury. In a previous clinical study, we found an S 100 B increase within the first 24 h in patients with multiple trauma and hemorrhagic shock but without cerebral trauma. The aim of our current experimental study was to determine whether this posttraumatic S 100 B increase is caused by extracerebral soft tissue injury or by hemorrhagic shock and whether it is associated with the severity of hemorrhagic shock. Hemorrhagic shock was achieved by bleeding anesthetized rats to a mean arterial pressure (MAP) of 30-35 mmHg through a femoral catheter and maintaining this MAP until incipient decompensation. At incipient decompensation, MAP was either increased immediately to 40-45 mmHg (moderate shock) or was maintained until 40% of shed blood had been returned (severe shock), and then increased to 40-45 mmHg. Resuscitation was provided after 40-45 mmHg MAP had been maintained for 40 min. Soft tissue injury was achieved by midline laparotomy performed at the onset of hemorrhagic shock or without shock and was maintained for 30 min. Hemorrhagic shock caused an early S 100 B increase at the onset of decompensation. S 100 B remained increased for 24 h and was significantly higher after severe than after moderate shock. In contrast, soft tissue injury without hemorrhagic shock caused no S 100 B increase. The data presented demonstrate for the first time that the S 100 B increase is induced by hemorrhagic shock and is associated with the severity of shock.

Increased plasma D-lactate is associated with the severity of hemorrhagic/traumatic shock in rats.

D-lactate is produced by indigenous bacteria in the gastrointestinal tract. Mammals do not have the enzyme systems to metabolize D-lactate rapidly. The present study was designed to determine the kinetics of circulating D-lactate levels and to examine whether the severity of shock affects circulating D-lactate levels in rats subjected to hemorrhagic/traumatic shock. Anesthetized rats underwent midline laparotomy (duration 30 min) and were bled to 30-35 mmHg mean arterial pressure (MAP). After the onset of decompensation, MAP was either increased to 40-45 mmHg immediately by administration of Ringer's solution (moderate shock) or after 40% of shed blood volume had been re-infused as Ringer's solution (severe shock). MAP was then maintained at 40-45 mmHg for 40 min by further administration of Ringer's solution (inadequate resuscitation). Subsequently, adequate resuscitation was performed for 60 min with shed blood and additional Ringer's solution. Metabolic acidosis was significantly more pronounced in severe than in moderate hemorrhagic/traumatic shock. Plasma D-lactate levels were already significantly increased at the end of severe hemorrhagic/traumatic shock and remained high during inadequate resuscitation. D-lactate levels were significantly higher after severe than after moderate shock. Endotoxin levels did not correlate with shock severity. Damage to the intestinal mucosa was more profound in severe shock than in moderate shock. Our data suggest that hemorrhagic/traumatic shock is associated with mucosal damage and increased plasma D-lactate levels. The severity of shock affects D-lactate concentrations in plasma. Plasma D-lactate may be a useful marker of intestinal injury after hemorrhagic/traumatic shock.

Release of S100B differs during ischemia and reperfusion of the liver, the gut, and the kidney in rats.

S100B, an acknowledged marker of brain damage, is increased post-traumatically in plasma. The aim of this study was to investigate the diagnostic value of S100B release in experimental local extracranial ischemia and reperfusion. Anesthetized rats underwent laparotomy and ligation of the afferent blood vessels to the liver, gut, or kidney to achieve local ischemia in each organ separately. After 60 min of ischemia, ligatures were removed and resuscitation was performed for 3 h. S100B was determined in plasma by immunoluminometric assay 55, 65, and 240 min after the onset of ischemia (5 min before reperfusion and 5 min and 3 h after the onset of reperfusion). During ischemia of the liver, S100B increased before ligature removal and reperfusion, reaching significance early after the onset of reperfusion and remaining almost unchanged throughout reperfusion. In contrast, S100B did not increase during ischemia of the gut or kidney before ligature removal or during early reperfusion but increased significantly to similar levels as during reperfusion of the liver 240 min after the onset of ischemia (after 3 h of reperfusion). Our findings show for the first time that S100B increases during local extracranial ischemia and reperfusion. These experimental findings support the concept that brain damage is not necessarily the cause of increased S100B. Although S100B has been an acknowledged marker of brain damage for years, our experimental clinically relevant data indicate that S100B is, in fact, not specific as a marker of brain damage in the setting of local ischemia and reperfusion of the liver, gut, and kidney because local ischemia and reperfusion of these organs cause an S100B increase per se.

[Update treatment of hepatic encephalopathy]. / Hepaticus encephalopathia korszeru kezelése.

According to morbidity data in Hungary, the number of death caused by liver diseases is still high. Liver diseases come 6th on the morbidity statistics. Nowadays, the living standards of patients appropriately treated are higher, these patients have longer living perspectives. Author aims at summarizing the treatment options of hepatic encephalopathy in cases of subclinical, acute and chronic forms of chronic liver diseases as well as in case of fulminant form of acute liver disorder.

17beta-Estradiol modulates vasoconstriction induced by endothelin-1 following trauma-hemorrhage.

Although endothelin-1 (ET-1) induces vasoconstriction, it remains unknown whether 17beta-estradiol (E(2)) treatment following trauma-hemorrhage alters these ET-1-induced vasoconstrictive effects. In addition, the role of the specific estrogen receptor (ER) subtypes (ER-alpha and ER-beta) and the endothelium-localized downstream mechanisms of actions of E(2) remain unclear. We hypothesized that E(2) attenuates increased ET-1-induced vasoconstriction following trauma-hemorrhage via an ER-beta-mediated pathway. To study this, aortic rings were isolated from male Sprague-Dawley rats following trauma-hemorrhage with or without E(2) treatment, and alterations in tension were determined in vitro. Dose-response curves to ET-1 were determined, and the vasoactive properties of E(2), propylpyrazole triol (PPT, ER-alpha agonist), and diarylpropionitrile (DPN, ER-beta agonist) were determined. The results showed that trauma-hemorrhage significantly increased ET-1-induced vasoconstriction; however, administration of E(2) normalized ET-1-induced vasoconstriction in trauma-hemorrhage vessels to the sham-operated control level. The ER-beta agonist DPN counteracted ET-1-induced vasoconstriction, whereas the ER-alpha agonist PPT was ineffective. Moreover, the vasorelaxing effects of E(2) were not observed in endothelium-denuded aortic rings or by pretreatment of the rings with a nitric oxide (NO) synthase inhibitor. Cyclooxygenase inhibition with indomethacin had no effect on the action of E(2). Thus, E(2) administration attenuates ET-1-induced vasoconstriction following trauma-hemorrhage via an ER-beta-mediated pathway that is dependent on endothelium-derived NO synthesis.

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.

Androstenediol ameliorates alterations in immune cells cytokine production capacity in a two-hit model of trauma-hemorrhage and sepsis.

Although administration of androstenediol (a metabolite of dehydroepiandrosterone) following trauma-hemorrhage (T-H) produces beneficial effects on inflammatory cytokines and organ function, it remains unknown whether this metabolite has any salutary effects in preventing alterations in immune cell cytokine production following a combined insult of T-H and sepsis. To examine this, male rats underwent laparotomy, hemorrhagic shock (mean BP 40 mmHg for 90 min) and resuscitation or sham operation. Androstenediol (1 mg/kg BW i.v.) or vehicle was administered at the end of resuscitation. Twenty hrs after T-H or sham operation, sepsis was induced by cecal ligation and puncture (CLP). Five hours thereafter, plasma cytokine levels and cytokine production of various immune cells were determined. In a separate set of experiments, survival was monitored for 10 days after the induction of sepsis. Administration of androstenediol markedly decreased plasma IL-6 and TNF-alpha levels following T-H and CLP. Furthermore, it prevented the increased production of IL-6 and TNF-alpha by Kupffer cells and alveolar macrophages and attenuated the decrease in IL-6 and TNF-alpha production by splenic macrophages; however, it had no significant effects on the depressed IL-6 and TNF-alpha production by PBMC following T-H and CLP. The depressed IL-2 and IFN-gamma production by splenocytes under those conditions was attenuated by the administration of androstenediol. Furthermore, survival rate following T-H and subsequent sepsis was improved by androstenediol treatment. Since androstenediol administration following T-H attenuated cytokine production and reduced mortality in a double-hit model of T-H and sepsis, this agent appears to be a novel and useful adjunct for maintaining the immune cell functions following T-H and for decreasing the mortality rate from subsequent susceptibility to sepsis.

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.