Capacitation and Ca2+ influx in spermatozoa: Role of CNG channels and protein kinase G

Cyclic guanosine monophosphate (cGMP) has been recently shown to modulate in vitro capacitation of mammalian spermatozoa, but the mechanisms through which it influences sperm functions have not been clarified. There are at least two targets of cGMP, cyclic nucleotide-gated (CNG) channels and cGMP-dependent protein kinase (PKG), involved in several physiological events in mammalian spermatozoa. It has been suggested that CNG channels allow the influx of Ca2+ to cytoplasm during capacitation, whereas PKG could trigger a phosphorylation pathway which might also, indirectly, mediate calcium entry. Using the patch-clamp technique in whole-cell configuration, we showed how l-cis-Diltiazem (a CNG-channel inhibitor) and KT5823 (a PKG inhibitor) decreased significantly the amplitude of macroscopic ion currents in a dose-response manner, and decreased in vitro capacitation. The inhibition of CNG channels completely abolishes the Ca2+ influx induced by cyclic nucleotides in mouse spermatozoa. This work suggests that the downstream cGMP pathway is required in mammalian sperm capacitation and the mechanisms involved include CNG channels and PKG, highlighting these molecules as important therapeutic targets for infertility treatments or to develop new male contraceptives. Zapotitlán 2013 American Society of Andrology and European Academy of Andrology

Nitric oxide synthases inhibition results in renal failure improvement in cirrhotic rats

Nitric oxide (NO) has been implicated in cirrhosis and might be implicated in renal failure end-stage cirrhosis. Aim: Our aim was to evaluate NO role in renal failure induced during decompensated cirrhosis, using the following inhibitors: aminoguanidine (AG), a specific inducible nitric oxide synthase (iNOS) inhibitor and NG-nitro-L-arginine methyl ester (L-NAME), a nonselective blocker of NOS isoforms. Methods: Endothelial (eNOS) and iNOS gene expression was analyzed by reverse transcriptase-polymerase chain reaction. Cirrhotic rats received a single intragastric dose of CCl4 to induce acute liver damage (ALD). Results: After ALD, aspartate aminotransferase highest levels were observed in rats treated with AG and ALT in rats treated with L-NAME. Inhibitors decreased creatinine serum levels to normal values and serum sodium levels re-established after the third day of ALD. L-NAME diminished (P<0.05) eNOS RNA renal expression. Renal iNOS with no inhibitor was overexpressed but was down-regulated by AG treatment. Liver eNOS RNA expression had a decreased expression before ALD in cirrhotic rats, but L-NAME treatment down-regulated eNOS after ALD. AG induced an important iNOS liver decrease. Conclusion: Both inhibitors improved renal function, although AG displayed a better effect and did not aggravate liver function. We concluded that NOS isoforms are implicated in the renal pathophysiologic events induced by ALD. © Blackwell Munksgaard 2005

Nitric Oxide Donors as Neuroprotective Agents after an Ischemic Stroke-Related Inflammatory Reaction

Cerebral ischemia initiates a cascade of detrimental events including glutamate-associated excitotoxicity, intracellular calcium accumulation, formation of Reactive oxygen species (ROS), membrane lipid degradation, and DNA damage, which lead to the disruption of cellular homeostasis and structural damage of ischemic brain tissue. Cerebral ischemia also triggers acute inflammation, which exacerbates primary brain damage. Therefore, reducing oxidative stress (OS) and downregulating the inflammatory response are options that merit consideration as potential therapeutic targets for ischemic stroke. Consequently, agents capable of modulating both elements will constitute promising therapeutic solutions because clinically effective neuroprotectants have not yet been discovered and no specific therapy for stroke is available to date. Because of their ability to modulate both oxidative stress and the inflammatory response, much attention has been focused on the role of nitric oxide donors (NOD) as neuroprotective agents in the pathophysiology of cerebral ischemia-reperfusion injury. Given their short therapeutic window, NOD appears to be appropriate for use during neurosurgical procedures involving transient arterial occlusions, or in very early treatment of acute ischemic stroke, and also possibly as complementary treatment for neurodegenerative diseases such as Parkinson or Alzheimer, where oxidative stress is an important promoter of damage. In the present paper, we focus on the role of NOD as possible neuroprotective therapeutic agents for ischemia/reperfusion treatment

PGE2 alleviates kidney and liver damage, decreases plasma renin activity and acute phase response in cirrhotic rats with acute liver damage

In this study, we evaluated the effect of prostaglandin E2 (PGE2) on renal and hepatic function using an experimental cirrhosis model plus acute liver damage (ALD). Male Wistar rats treated with carbon tetrachloride (CCl4) for 8 weeks were used for the cirrhosis model. Cirrhotic rats were further exposed to an additional acute dose of CCl 4 to induce ALD and then treated with PGE2 intramuscularly twice a day for 7 days (200 μg/Kg/day). PGE2 administration started 3 h after the additional dosing of CCl4 and PGE2 effect on hepatorenal function was examined on days 1, 2, 3, and 7. PGE 2-treatment ameliorated the decrease in urinary sodium excretion, and normalized serum activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and plasma renin observed in cirrhotic rats with ALD. In addition, PGE2-treatment decreased mean arterial pressure, glomerular hypercellularity and thickening of the kidney capillary wall, and liver steatosis and cellular necrosis. Also, PGE2 increased the number of regenerative nodules. Finally, PGE2-treatment inhibited the increase in Alpha 1-acid glycoprotein (pAGP), fibrinogen, and Apo A-1 mRNA expression by 83%, 59%, and 77%, respectively. These results suggest that PGE2 administration may decrease the expression of acute phase proteins. In conclusion, PGE2-treatment improved hepatic and renal function and may be useful to down-regulate the acute phase response in cirrhotic rats presenting ALD induced by CCl4. © 2004 Elsevier GmbH. All rights reserved

Pharmacogenetics and antiepileptic drug metabolism: Implication of genetic variants in cytochromes P450 [Farmacogenética y metabolismo de formacos antiepilépticos: Implicación de variantes genéticas en citocromos P1450]

In this study, we evaluated the effect of prostaglandin E2 (PGE2) on renal and hepatic function using an experimental cirrhosis model plus acute liver damage (ALD). Male Wistar rats treated with carbon tetrachloride (CCl4) for 8 weeks were used for the cirrhosis model. Cirrhotic rats were further exposed to an additional acute dose of CCl 4 to induce ALD and then treated with PGE2 intramuscularly twice a day for 7 days (200 ?g/Kg/day). PGE2 administration started 3 h after the additional dosing of CCl4 and PGE2 effect on hepatorenal function was examined on days 1, 2, 3, and 7. PGE 2-treatment ameliorated the decrease in urinary sodium excretion, and normalized serum activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and plasma renin observed in cirrhotic rats with ALD. In addition, PGE2-treatment decreased mean arterial pressure, glomerular hypercellularity and thickening of the kidney capillary wall, and liver steatosis and cellular necrosis. Also, PGE2 increased the number of regenerative nodules. Finally, PGE2-treatment inhibited the increase in Alpha 1-acid glycoprotein (pAGP), fibrinogen, and Apo A-1 mRNA expression by 83%, 59%, and 77%, respectively. These results suggest that PGE2 administration may decrease the expression of acute phase proteins. In conclusion, PGE2-treatment improved hepatic and renal function and may be useful to down-regulate the acute phase response in cirrhotic rats presenting ALD induced by CCl4. " 2004 Elsevier GmbH. All rights reserved.",,,,,,"10.1016/j.etp.2004.10.003",,,"http://hdl.handle.net/20.500.12104/43551","http://www.scopus.com/inward/record.url?eid=2-s2.0-14644424576&partnerID=40&md5=e679c9ae8f77189edf81017e6c45f90a",,,,,,"04-may",,"Experimental and Toxicologic Pathology",,"29

MIF and TNF? serum levels in rheumatoid arthritis patients treated with disease-modifying antirheumatic drugs: A cross-sectional study

Macrophage migration inhibitory factor (MIF) and tumor necrosis factor alpha (TNF?) play a pivotal role in rheumatoid arthritis (RA). MIF is considered a relevant cytokine because it appears before TNF? in the inflammatory cascade thus stimulating TNF? production and MIF's relationship with traditional synthetic disease modifying antirheumatic drugs (sDMARDs) is unknown. In this cross-sectional study, we investigated the association of MIF and TNF? serum levels with methotrexate (MTX) and in combination with chloroquine (CLQ) and sulfasalazine (SSZ) in RA patients classified according to the ACR/EULAR 2010 criteria. Patients were divided into three groups: MTX-monotherapy group (n40), MTX combination therapy groups: MTXCLQ (n41), and MTXCLQSSZ (n42). MIF and TNF? serum levels were determined by ELISA. We found high levels of ESR, CRP, RF, and anti-CCP in all therapy groups. Furthermore, we subclassified 97 patients with established RA (?2 years of disease duration) and found that TNF? serum levels were lower in the combination therapy group (MTX + CLQ + SSZ) in comparison with the monotherapy MTX group (16.7pg/mL versus 13.6pg/mL, p0.02). However, we did not find differences between sDMARD therapies in MIF serum levels. We did find a significant reduction in MIF serum levels in patients treated with oral steroids compared with patients without oral steroids (1.7ng/mL versus 4.3ng/mL, p<0.001). In conclusion, this study supports the role of sDMARDs in modifying TNF? serum levels and oral steroids MIF serum levels. Nevertheless, we found that MIF serum levels are not modified by sDMARD treatment. � 2015 Informa Healthcare USA, Inc. All rights reserved

Cu/Zn superoxide dismutase (SOD1) induction is implicated in the antioxidative and antiviral activity of acetylsalicylic acid in HCV-expressing cells

We evaluated the participation of oxidative stress in the negative regulation of hepatitis C virus (HCV)- RNA induced by acetylsalicylic acid (ASA). We used the HCV subgenomic replicon cell system that stably expresses HCV-nonstructural proteins (Huh7 HCV replicon cells) and the parental cell line. Cells were exposed to 4 mM ASA at different times (12-72 h), and pyrrolidine dithiocarbamate (PDTC) was used as an antioxidant control. Reactive oxygen species (ROS) production, oxidized protein levels, cytosolic superoxide dismutase (Cu/Zn-SOD), and glutathione peroxidase (GPx) activity were measured to evaluate oxidative stress. In addition, viral RNA and prostaglandin (PGE 2) levels were determined. We observed that ASA treatment decreased ROS production and oxidized protein levels in a time-dependent fashion in both parental and HCV replicon cells with a greater extent in the latter. Similar results were found with PDTC exposure. Average GPx activity was decreased, whereas a striking increase was observed in average cytosolic SOD activity at 48 and 72 h in both cells exposed to ASA, compared with untreated cells. HCV replicon cells showed higher levels of Cu/Zn-SOD expression (mRNA and protein) with ASA treatment (48 and 72 h), whereas NS5A protein levels showed decreased expression. In addition, we found that inhibition of SOD1 expression reversed the effect of ASA. Interestingly, PDTC downregulated HCV-RNA expression (55%) and PGE 2 (60%) levels, imitating ASA exposure. These results suggest that ASA treatment could reduce cellular oxidative stress markers and modify Cu/Zn- SOD expression, a phenomenon that may contribute to the mechanisms involved in HCV downregulation. � 2012 by the American Physiological Society