Surgical intervention is currently the only option for an abdominal aortic aneurysm (AAA), preventing its rupture and sudden death of a patient. Therefore, it is crucial to determine the pathogenic mechanisms of this disease for the development of effective pharmacological therapies. Oxidative stress is said to be one of the pivotal factors in the pathogenesis of AAAs. Thus, we aimed to evaluate the significance of nuclear factor erythroid 2-related factor 2 (Nrf2) transcriptional activity in the development of AAA and to verify if simvastatin, administered as pre- and cotreatment, may counteract this structural malformation. Experiments were performed on mice with inhibited transcriptional activity of Nrf2 (tKO) and wild-type (WT) counterparts. We used a model of angiotensin II- (AngII-) induced AAA, combined with a fat-enriched diet. Mice were administered with AngII or saline for up to 28 days via osmotic minipumps. Simvastatin administration was started 7 days before the osmotic pump placement and then continued until the end of the experiment. We found that Nrf2 inactivation increased the risk of development and rupture of AAA. Importantly, these effects were reversed by simvastatin in tKO mice, but not in WT. The abrupt blood pressure rise induced by AngII was mitigated in simvastatin-treated animals regardless of the genotype. Simvastatin-affected parameters that differed between the healthy structure of the aorta and aneurysmal tissue included immune cell infiltration of the aortic wall, VCAM1 mRNA and protein level, extracellular matrix degradation, TGF-β1 mRNA level, and ERK phosphorylation, but neither oxidative stress nor the level of Angiotensin II Type 1 Receptor (AT1R). Taken together, the inhibition of Nrf2 transcriptional activity facilitates AAA formation in mice, which can be prevented by simvastatin. It suggests that statin treatment of patients with hypercholesterolemia might have not only a beneficial effect in terms of controlling atherosclerosis but also potential AAA prevention.

BackgroundCurcumin is a natural polyphenol with anti-inflammatory, chemopreventive and anticancer activity. However, its high hydrophobicity and poor bioavailability limit its medical application. The development of nanocarriers for curcumin delivery is an attractive approach to overcome its low bioavailability and fast metabolism in the liver. We synthesized a blood compatible alginate-curcumin conjugate, AA-Cur, which formed colloidally stable micelles of approximately 200 nm and, as previously shown, exerted strong cytotoxicity against mouse cancer cell lines. Here we analyze in vivo toxicity and antitumor activity of AA-Cur in two different mouse tumor models.MethodPotential toxicity of intravenously injected AA-Cur was evaluated by: i) analyses of blood parameters (morphology and biochemistry), ii) histology, iii) DNA integrity (comet assay), and iv) cytokine profiling (flow cytometry). Antitumor activity of AA-Cur was evaluated by measuring the growth of subcutaneously inoculated colon MC38-CEA- or orthotopically injected breast 4T1 tumor cells in control mice vs mice treated with AA-Cur.ResultsInjections of four doses of AA-Cur did not reveal any toxicity of the conjugate, thus indicating the safety of its use. AA-Cur elicited moderate anti-tumor activity toward colon MC38-CEA or breast 4T1 carcinomas.ConclusionThe tested conjugate of alginate and curcumin, AA-Cur, is non-toxic and safe, but exhibits limited anticancer activity.

No abstract

Abdominal aortic aneurysm (AAA) bears a high risk of rupture and sudden death of the patient. The pathogenic mechanisms of AAA remain elusive, and surgical intervention represents the only treatment option. Heme oxygenase-1 (HO-1), a heme degrading enzyme, is induced in AAA, both in mice and humans. HO-1 was reported to mitigate AAA development in an angiotensin II (AngII)-induced model of AAA in hyperlipidemic ApoE-/- mice. Since the role of hyperlipidaemia in the pathogenesis of AAA remains controversial, we aimed to evaluate the significance of HO-1 in the development and progression of AAA in normolipidemic animals. The experiments were performed in HO-1-deficient mice and their wild-type counterparts. We demonstrated in non-hypercholesterolemic mice that the high-dose of AngII leads to the efficient formation of AAA, which is attenuated by HO-1 deficiency. Yet, if formed, they are significantly more prone to rupture upon HO-1 shortage. Differential susceptibility to AAA formation does not rely on enhanced inflammatory response or oxidative stress. AAA-resistant mice are characterized by an increase in regulators of aortic remodeling and angiotensin receptor-2 expression, significant medial thickening, and delayed blood pressure elevation in response to AngII. To conclude, we unveil a dual role of HO-1 deficiency in AAA in normolipidemic mice, where it protects against AAA development, but exacerbates the state of formed AAA.

No abstract

1. Intravenous infusion of propranolol(3.86 pmol h-l kg-I) for 2 h lowered arterial pressure in the conscious rabbit whereas similar infusions of practolol (37.6 pmol h-I kg-I) did not.2. The fall in blood pressure produced by propranolol was accompanied by a decrease in splanchnic nerve activity. Practolol did not change splanchnic nerve activity.3. A centrally mediated decrease in sympathetic nervous activity makes an important contribution to the hypotensive action of propranolol in the rabbit. This effect is not shown by practolol.Key words: anti-hypertensive drugs, practolol, propranolol, splanchnic nerve activity. 549s 550s P. J. Lewis

No abstract

The serum and total body potassium was investigated in 25 patients with non-congestive cardaic failure before and during saluretic treatment. Treatment with triamterene (100 mg/d; n = 10) over a period of 3 weeks led to an increase of serum potassium (from 4.1 +/- 0.65 to 4.7 +/- 0.51 mmol/l) and of total body potassium (by 110 mmol). After treatment with chlortalidon for 7 days (100 mg/d; n = 6) serum potassium concentration decreased from 4.38 "/- 0.37 to 3.30 +/- 0.46 mmol/l (approximately 25%). The total body potassium decreased by 240 mmol (approximately 10%). Continuation of the treatment with a combination of chlortalidon (50 mg/d) and triamterene (150 mg/d) led to correction of the extra- and intracellular potassium loss after 1 to 2 weeks. No significant change of serum and total body potassium was found during and after 6 months of treatment with hydrochlorothiazide (50 mg/d) and triamterene (100 mg/d; n = 9). The results demonstrate the potassium loss which occurs in the early stage of saluretic treatment and show the antikaluretic potency of triamterene.