Vitamin E and Silymarin Reduce Oxidative Tissue Damage during Gentamycin-Induced Nephrotoxicity.

Aminoglycoside antibiotics and gentamicin (GN), in particular, are still widely used in clinical practice. It is a well-known fact that GN causes nephrotoxicity, and redox disturbances are discussed as a factor in its side effects. Recently, a new type of cell oxidative death, named ferroptosis, was discovered; it is associated with iron accumulation in the cell, glutathione (GSH) depletion and inactivation of glutathione peroxidase-4 (GPX4), reactive oxygen species (ROS) increment with concomitant lipid peroxidation. In this regard, a possible connection between GN-induced renal damage, ferroptosis and the overall antioxidant status of the organism could be investigated. Moreover, due to its beneficial effects, GN is still one of the main choices as a therapeutic agent for several diseases, and the possible reduction of its side effects with the application of certain antioxidants will be of important clinical significance. The study was conducted with adult male white mice divided into several groups (n = 6). GN nephrotoxicity was induced by the administration of GN 100-200 mg/kg i.p. for 10 days. The control group received only saline. The other groups received either Vitamin E (400 mg/kg p.o.) or Silymarin (200 mg/kg p.o.) applied alone or together with GN for the same period. After the end of the study, the animals were sacrificed, and blood and tissue samples were taken for the assessment of biochemical parameters and antioxidant status, as well as routine and specific for GPX4 histochemistry examination. The experimental results indicate that GN-induced nephrotoxicity negatively modulates GPX4 activity and is associated with increased production of ROS and lipid peroxidation. The groups treated with antioxidants demonstrated preserved antioxidant status and better GPX4 activity. In conclusion, the inhibition of ROS production and especially the suppression of ferroptosis, could be of clinical potential and can be applied as a means of reducing the toxic effects of GN application.

Analysis of angiotensin II-Induced rat urinary bladder contractions in the presence of angiotensin II receptors blockers.

OBJECTIVE: An application of a specific analysis on recordings obtained from urinary bladder (UB) preparations influenced with Angiotensin II (AngII) and AngII receptor (ATR) blockers was performed. METHODS: UB preparations were divided as follows: group 1 stimulated with AngII only; group 2:PD123319 (ATR type-2 blocker)+AngII; group 3:Losartan (ATR type-1 blocker)+AngII. The averaged time and force parameters of the contractions were processed by a spline interpolation and graphic images of the different patterns of the contractile activity were obtained. RESULTS: The speed of AngII-induced UB contraction, when PD123319 was administered, was significantly higher than those, registered by the application of AngII alone and Losartan + AngII. The presence of Losartan markedly delayed the speed of the overall AngII-induced contraction. CONCLUSION: The study indicates the contribution of both ATR subtypes for the development of AngII-induced UB contraction. Our results showed that probably ATR mediate a reciprocal dynamic response to AngII in the bladder.

Metabolic Disorders Induced by Fructosedrinking Water Affect Angiotensin II-mediated Intestinal Contractility in Male Wistar Rats.

INTRODUCTION: The high-fructose diet in rats has been reported to cause metabolic disorders such as impaired fasting glucose levels, in-sulin resistance, dyslipidemia, and dysregulation of the renin-angiotensin system. This could lead to further complications, for instance, to the smooth muscle dysfunction. AIM: The present study aimed at developing fructose-induced metabolic perturbations in rats and the investigation of their impact on angiotensin II-induced smooth muscle intestinal motility. MATERIALS AND METHODS: Mature Wistar rats were randomly divided into two groups (9 rats per group): control group (drinking tap water) and fructose-drinking group (15% fructose, dissolved in tap water). At the end of the experimental period (11 weeks), the plasma levels of insulin, renin, angiotensin II and creatinine, as well as the lipid profile were assessed. Morphometric analysis and lipid index calculation were also performed. The contractile properties of ileum, colon and rectum were studied using stimulation with angiotensin II in the isolated tissue bath system. RESULTS: Our experiment showed that drinking 15% fructose solution induced dyslipidaemia accompanied by elevated lipid indexes as well as an increase in creatinine and renin plasma levels in the rats. CONCLUSIONS: Fructose drinking and consequently the developed metabolic disorders modified the Ang II-induced intestinal activity causing a gradual alteration in the distal direction with the rectum being the most strongly affected organ.