Marta Góralska

Atorvastatin affects the tissue concentration of hydrogen sulfide inmouse kidneys and other organs

Hydrogen sulfide (H2S) is a crucial co-modulator of cardiovascular, nervous, digestive and excretory systems function. The pleiotropic action of atorvastatin exceeds simple 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibition and involves multiple biological mechanisms. This study assesses the influence of atorvastatin on the H2S tissue concentration in mouse brain, liver, heart and kidney. Twenty-four female CBA strain mice received an intraperitoneal injection. The mice were given one of the following solutions: 0.1 mg atorvastatin (5 mg/kg of body weight (b.w.)/day--group D1, n=8), 0.4 mg atorvastatin (20 mg/kg b.w./day--group D2, n=8) or a saline physiological control (0.2 ml--group C, n=8). A modified Siegel spectrophotometric method was used for the H2S tissue concentration measurements. There was a remarkable rise in the H2S concentration [μg/g] in the kidney (C: 5.26±0.09, D1: 5.77±0.11, p=0.0003; D2: 7.48±0.09, p<0.0001). There were also slight H2S tissue level changes in the brain (C: 1.61±0.01, D1: 1.75±0.03, p=0.0001; D2: 1.78±0.03, p<0.0001), the heart (C: 4.54±0.08, D1: 4.86±0.10, p=0.0027; D2: 4.56±0.07, p=0.6997) and the liver (C: 3.45±0.03, D1: 3.27±0.02, p=0.0001; D2: 3.31±0.02, p=0.0003). Our study supports the influence of atorvastatin on H2S tissue concentration in kidneys and other mouse organs.

Effects of aspirin on the levels of hydrogen sulfide and sulfane sulfur in mouse tissues

This study was designed to investigate the effect of aspirin (ASA) on anaerobic cysteine metabolism, which yields sulfane sulfur-containing compounds and hydrogen sulfide (H(2)S), in mouse liver and brain. In order to solve this problem, we determined the levels of sulfane sulfur and H(2)S, and the activities of cystathionase, the enzyme directly engaged in H(2)S synthesis, and rhodanese, the enzyme that catalyzes sulfane sulfur transfer to different acceptors. Moreover, we examined the effect of ASA on glial Gomori-positive cells (GGPC) in the brain that contain sulfur-rich glial Gomori-positive material (GGPM). The studies indicated an ASA-induced decrease in H(2)S levels in the brain and an increase in the liver. ASA-treated animals had lower cerebral levels of GGPM-containing GGPCs but the sulfane sulfur level was not affected. Conversely, the sulfane sulfur content in the liver dropped. ASA did not change cystathionase and rhodanese activity in either organ. The obtained results revealed that ASA was able to influence anaerobic cysteine metabolism, leading to the formation of sulfane sulfur and H(2)S in the mouse liver and brain, and to affect the numbers of GGPM-containing GGPCs.

The glial Gomori-positive material is sulfane sulpfur.

The Gomori-positive glia are periventricular astrocytes with abundant cytoplasmic granular material, predominantly occupying a periventricular site in the brain. These granular inclusions are strongly stained with chrome hematoxylin in the Gomoris method as well as exhibit red autofluorescence and non-enzymatic peroxidase activity. The glial Gomori-positive material (GGPM) granules are positive in the performic acid Alcian blue method indicating the presence of protein-bound sulfur, what has been shown by our previous studies. The number of cells containing glial Gomori-positive granules dropped after administration of cyanide and increased under the influence of sulfane sulfur donor (diallyl disulfide). This suggests, that sulfur of these granules is a sulfane sulfur, possibly in the form of protein-bound cysteine persulfide. Sulfane sulfur is labile, reactive sulfur atom covalently bound to another sulfur atom. In this paper we present evidence that GGPM exhibit affinity to cyanolysis and its stainability in Gomoris method is due to the presence of protein-bound sulfane sulfur. The biological role of the Gomori-positive glia connected with protective properties of sulfane sulfur has been discussed.

Effects of Melatonin and Its Analogues on Pancreatic Inflammation, Enzyme Secretion, and Tumorigenesis

Melatonin is an indoleamine produced from the amino acid l-tryptophan, whereas metabolites of melatonin are known as kynuramines. One of the best-known kynuramines is N1-acetyl-N1-formyl-5-methoxykynuramine (AFMK). Melatonin has attracted scientific attention as a potent antioxidant and protector of tissue against oxidative stress. l-Tryptophan and kynuramines share common beneficial features with melatonin. Melatonin was originally discovered as a pineal product, has been detected in the gastrointestinal tract, and its receptors have been identified in the pancreas. The role of melatonin in the pancreatic gland is not explained, however several arguments support the opinion that melatonin is probably implicated in the physiology and pathophysiology of the pancreas. (1) Melatonin stimulates pancreatic enzyme secretion through the activation of entero-pancreatic reflex and cholecystokinin (CCK) release. l-Tryptophan and AFMK are less effective than melatonin in the stimulation of pancreatic exocrine function; (2) Melatonin is a successful pancreatic protector, which prevents the pancreas from developing of acute pancreatitis and reduces pancreatic damage. This effect is related to its direct and indirect antioxidant action, to the strengthening of immune defense, and to the modulation of apoptosis. Like melatonin, its precursor and AFMK are able to mimic its protective effect, and it is commonly accepted that all these substances create an antioxidant cascade to intensify the pancreatic protection and acinar cells viability; (3) In pancreatic cancer cells, melatonin and AFMK activated a signal transduction pathway for apoptosis and stimulated heat shock proteins. The role of melatonin and AFMK in pancreatic tumorigenesis remains to be elucidated.

MELATONIN AND ITS METABOLITE N1-ACETYL-N2-FORMYL-5-METHOXYKYNURAMINE (AFMK) ENHANCE CHEMOSENSITIVITY TO GEMCITABINE IN PANCREATIC CARCINOMA CELLS (PANC-1)

BACKGROUND Gemcitabine is a standard chemotherapeutic agent for patients suffering from pancreatic cancer. However, the applied therapy is not effective due to the resistance of tumor cells to cytostatics, caused by inefficiency of the apoptotic mechanisms. Herein, we present the hypothesis that melatonin and its metabolite N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) modify the effect of gemcitabine on PANC-1 cells and that this phenomenon is dependent on the modulation of apoptosis. METHODS PANC-1 cells have been incubated with melatonin, AFMK or gemcitabine alone or in combination to determine the cytotoxity and proliferative effects. In subsequent part of the study, cells were harvested, the proteins were isolated and analyzed employing immunoprecipitation/immunoblotting. RESULTS Incubation of PANC-1 cells with gemcitabine resulted in upregulation of pro-apoptotic bax and caspases proteins expression, downregulation of anti-apoptotic Bcl-2, heat shock proteins (HSPs) and modulation of cellular inhibitors of apoptosis (IAPs). Both melatonin and AFMK administered to PANC-1 in combination with gemcitabine inhibited the production of HSP70 and cIAP-2 as compared to the results obtained with gemcitabine alone. These changes were accompanied by upregulation of Bax/Bcl-2 ratio and reduction of procaspases-9 and -3 abundance, followed by an increase in the formation of active caspase of PANC-1 cells with combination of gemcitabine plus low doses of melatonin or AFMK led to enhanced cytotoxicity and resulted in the inhibition of PANC-1 cells growth as compared to effects of gemcitabine alone. CONCLUSION Melatonin and AFMK could improve the anti-tumor effect of gemcitabine in PANC-1 cells presumably through the modulation of apoptotic pathway.

Corrigendum to “Epicutaneous immunization with protein antigen TNP-Ig alleviates TNBS-induced colitis in mice” [Pharmacol. Rep. 64 (2012) 1497–1504]

The authors wish to note an incorrectly listed financial support grant. The National Science Centre grant UMO-2011/01/B/NZ6/00300 was inadvertently listed. The authors regret this error. The correct Acknowledgements read as follows.The authors wish to note an incorrectly listed financial support grant. The National Science Centre grant UMO-2011/01/B/NZ6/00300 was inadvertently listed. The authors regret this error. The correct Acknowledgements read as follows.