Carvedilol ameliorates dexamethasone-induced myocardial injury in rats independent of its action on the α1-adrenergic receptor.

The current study aimed to investigate the cardiotoxic effect of dexamethasone-high-dose in rats, the therapeutic effect of carvedilol and the role of α1-adrenergic receptor (α1AR). The experiment involved 6 groups: control, dexamethasone (10 mg/kg), carvedilol (10 mg/kg), phenylephrine (1 mg/kg), phenylephrine plus carvedilol and propranolol (30 mg/kg). Drugs and vehicles were given for 7 days. Dexamethasone was given with the drugs in the last 4 groups. On the 8th-day and after overnight fasting, serum and cardiac samples were collected. Serum levels of cardiac troponin I and creatine kinase-myoglobin as well as cardiac levels of diacylglycerol, malondialdehyde, kinase activity of Akt, transforming growth factor-ß, Smad3 and alpha smooth muscle actin were measured. Cardiac samples were also used for histopathological examination using hematoxylin-eosin and Sirius red stains, in addition to immunohistochemical examination using ß-arrestin2 antibody. Dexamethasone induced cardiac injury via increasing oxidative stress, apoptosis and profibrotic signals. Carvedilol significantly reduced the dexamethasone-induced cardiotoxicity. Using phenylephrine, a competitive α1-agonist, with carvedilol potentiated the cardioprotective actions of carvedilol. Propranolol, a ß-blocker without activity on α1ARs, showed higher cardiac protection than carvedilol. Dexamethasone-high-dose upregulates cardiac oxidative stress, apoptotic and profibrotic signals and induces cardiac injury. Blocking the α1-adrenergic receptor by carvedilol attenuates its cardioprotective effects against dexamethasone-induced cardiotoxicity.

Time-dependent expression of high-mobility group box-1 and toll-like receptors proteins as potential determinants of skin wound age in rats: Forensic implication.

The skin wound age determination in living subjects is an imperative task for forensic experts. In this study, we investigated the time-dependent expression of high-mobility group box-1 (HMGB1) and toll-like receptors 2 and 4 (TLR2 and 4) in rat skin wounds using real-time PCR and seek their forensic potentials during the skin wound repair process. In addition, the levels of serum pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6)), as well as nitric oxide (NO) production, were measured. The wound tissue and serum samples were collected after 30 min, 2 h, 6 h, 12 h, 1 day, 3 days, 5 days, and 7 days after incision. As a control (zero time), skin specimens and blood samples were collected without incision. The results reveal that the HMGB1, TLR2, and TLR4 expression levels were increased in a time-dependent manner until the first day where the peak level was achieved for the three tested genes compared with the zero time. On the 7th day, the statistical significance was lost for TLR2 and TLR4 but persisted for HMGB1. The serum TNF-α, IL6, and NO levels peaked within 30 min and 1st and 3rd day after injury, respectively. On the 7th day after incision, no significant differences exist in the TNF-α serum level compared to the control group, but the statistical significance persisted for IL6 and NO. It was apparent that the analyzed genes in the wound tissues showed higher R2 values rather than the serum biochemical indicators. Of note, a strong positive correlation was evident between the HMGB1 and that of TLR2 and TLR4 relative expression as well as IL-6 serum level. Conclusively, based on the observed changes in the analyzed markers in wound tissues and serum and R2 values obtained from mathematical models established to determine the wound age, the relative expression of HMGB1, TLR2, and TLR4 could be a reliable indicator for wound age determination in living subjects. Further investigation of these markers and mathematical models in human tissues is necessary.

Mitigation of dexamethasone-induced nephrotoxicity by modulating the activity of adrenergic receptors: Implication of Wnt/ß-arrestin2/ß-catenin pathway.

The present study aimed to investigate the role of α and ß-adrenergic receptors (ßARs) in mediation or modulation of the dexamethasone-induced nephrotoxicity by using different pharmacological interventions. Nephrotoxicity was induced by subcutaneous injection of dexamethasone (10 mg/kg) for 7 days in Wistar albino rats. Eight groups were used: control; dexamethasone; carvedilol; phenylephrine; carvedilol and phenylephrine; propranolol; doxazosin; propranolol and doxazosin. At the end of experiment, rats were euthanized and blood, urine and kidney samples were collected. Serum and urinary creatinine and urinary total protein levels were measured. Also, the renal tissue levels of diacylglycerol (DAG); Akt kinase activity, malondialdehyde (MDA), NADPH oxidase 2 (NOX2), transforming growth factor-ß (TGF-ß), Wnt3A and ß-catenin were recorded. Furthermore, histopathological and ß-arrestin2-immunohistochemical examinations of renal tissues were performed. Results: Dexamethasone induced glomerular damage, proteinuria, renal oxidative stress and upregulated the renal Wnt/ß-arrestin2/ß-catenin pathway and the profibrotic signals. Blocking the α1 and ßARs by carvedilol reduced the dexamethasone-induced nephrotoxicity. Pre-injection of phenylephrine did not reduce the reno-protective action of carvedilol. Blocking the ßARs only by propranolol reduced the dexamethasone-induced nephrotoxicity to the same extent of carvedilol group. Blocking the α1ARs only by doxazosin reduced dexamethasone-induced nephrotoxicity to a higher extent than other treatments. However, combined use of propranolol and doxazosin did not synergize the reno-protective effects of doxazosin. Conclusion: Dexamethasone induces nephrotoxicity, possibly, by upregulating the Wnt/ß-arrestin2/ß-catenin pathway. Blocking either α1ARs or ßARs can effectively protect against the dexamethasone-induced nephrotoxicity. However, combined blocking of α1ARs and ßARs does not synergize the reno-protective effects.

Early postmortem biochemical, histological, and immunohistochemical alterations in skeletal muscles of rats exposed to boldenone undecylenate: Forensic implication.

This study investigated the biochemical and histopathological alterations along with the immunoexpression pattern of heat shock protein 27 (Hsp27) within 6 h postmortem (PM) in skeletal muscle of boldenone (BOL)-treated rats. Forty-eight male rats were divided into two groups; a control group received sesame oil (0.25 mL/kg bwt), and BOL group received 5 mg/kg bwt BOL. Both treatments were intramuscularly injected once a week for eight weeks. Rats were euthanized by cervical dislocation, and the skeletal muscle specimens were collected at zero-time, 2, 4, and 6 h PM for biochemical and histopathological evaluations. The results revealed that BOL treatment significantly increased pH, MDA, ATP, ADP, glycogen, and hydroxyproline values. Still, it decreased the GPX, GST, and lactic acid levels, and Hsp27 immunoexpression compared to the control group. With increasing postmortem interval (PMI), whether control or BOL-treated, a significant reduction in pH value, markers of muscular antioxidant status, ATP, ADP, glycogen, hydroxyproline levels, as well as Hsp27 immunoexpression but a significant increase in lipid peroxidation and lactic acid content were recorded. Of note, the interaction between BOL treatment and PMI had a significant effect on ATP, ADP, lactic acid, hydroxyproline, GST, MDA, and TAC levels. Conclusively, these findings signify BOL exposure's modifying effect on the energy content, oxidative status, and histological architecture of skeletal muscles in the early PMI that reflected in delaying the onset of rigor mortis. For forensic practitioners, these findings should be highly considered at estimating PMI in athletic, AAS-treated patients, and fattening animals.