Antiarrhythmic effect of acute oxygen-ozone administration to rats.

The antiarrhythmic effects of 100; 150; and 300microg/kg i.p. oxygen/ozone mixture were tested on arrhythmias induced by i) ischemia; ii) ischemia/reperfusion; iii) aconitine (15microg/kg/i.v.); potassium chloride (1.5% i.v.) in rats. 25min of cardiac left descending coronary artery ischemia caused severe incidence of ventricular tachycardia, ventricular fibrillation and mortality. These were significantly reduced by pre-treatment of rats with oxygen/ozone mixture at doses of 150 and 300microg/kg. In separate experiments using a protocol of 5min ischemia followed by 8min reperfusion this caused arrhythmias starting within 6+/-1s. The incidence of ventricular tachycardia was 100%, while ventricular fibrillation occurred in 75% of the animals and lasted 85+/-14s. The mortality was 62.5%. These figures were significantly (P<0.01) reduced in animals treated with 150microg/kg oxygen/ozone and a substantial increase observed with 300microg/kg, whilst not affected by the lower dose of 100microg/kg. 150 and 300microg/kg oxygen/ozone prolonged the onset time for the appearance of arrhythmias induced by aconitine (300microg/kg oxygen/ozone, approximately 81% longer). Oxygen/ozone also reduced the ventricular tachycardia duration, ventricular fibrillation incidence, arrhythmia score, and increased the rat's survival rate. As for example, this latter was increased from 25% (aconitine) to 50% (aconitine+oxygen/ozone 150microg/kg). 100microg/kg oxygen/ozone was without effect. None of the oxygen/ozone doses affected the arrhythmias caused by potassium chloride 1.5% i.v. All the oxygen/ozone antiarrhythmic effects were similar to those observed with lidocaine (1.5mg/kg i.v.). In conclusion, oxygen/ozone has antiarrhythmic effects against arrhythmias caused by aconitine, myocardial ischemia and ischemia/reperfusion.

Use of a non-specific immunomodulation therapy as a therapeutic vasculogenesis strategy in no-option critical limb ischemia patients.

BACKGROUND/AIMS: Inflammatory mediators contribute to the impairment of vasculogenesis by reducing endothelial progenitor cells (EPCs) mobilization in atherosclerotic vasculopathy. We tested the hypothesis that administration of an oxygen/ozone mixture (IMT) might counteract this pathophysiological mechanism and enhance limb tissue perfusion in patients with critical limb ischemia (CLI). METHODS: Randomized patients with rest pain or ischemic ulcers and transcutaneous oxygen tension (TcPO(2)) <40 mmHg and/or toe pressure <50 mmHg received placebo (n=74) or a non-specific immunomodulation therapy (IMT) (n=77), autologous blood exposed to oxygen/ozone gas mixture by intragluteal injection, on day 1, 2, 7, and once a week thereafter for at least 22 weeks. Patients were evaluated for changes in TcPO(2), levels of circulating EPCs (CD34/KDR-positive cells) and inflammation (tumor necrosis factor-alpha-TNF-alpha). RESULTS: TcPO(2) and CD34/CD133-positive cells increased at 22 weeks in IMT group (P<0.01) whereas no changes were observed in placebo group. TNF-alpha levels decreased at 6 months in IMT group (P<0.001) whereas no changes were observed in placebo group. There was a strong positive correlation between CD34/KDR-positive cells and TcPO(2) (r=0.56, P<0.01). Moreover, there was an inverse correlation between CD34/KDR-positive cells and TNF-alpha (r=-0.51, P<0.01). CONCLUSIONS: Intramuscular injection of IMT may improve wound healing and limb salvage in patients with CLI.

A single subcutaneous injection of ozone prevents allodynia and decreases the over-expression of pro-inflammatory caspases in the orbito-frontal cortex of neuropathic mice.

The neuropathic pain model consisting of the spared nerve injury of the sciatic nerve was used in the mouse to examine whether peripheral neuropathy is capable of generating over-expression of pro-inflammatory and pro-apoptotic genes in the orbito-frontal cortex, together with allodynia and hyperalgesia. RT-PCR analysis showed increased expression of caspase-1, caspase-12 and caspase-8 genes in the orbito-frontal cortex 14 days after spared nerve injury of the sciatic nerve. Conversely, the expression of caspase-3 was decreased by spared nerve injury of the sciatic nerve in the same brain area. A single subcutaneous injection of ozone performed 12 h after the surgical procedure decreased mechanical allodynia and normalized the mRNA caspase-1, caspase-12 and caspase-8 gene levels, but did not the decrease caspase-3 level, 14 days post-spared nerve injury. Ozone also reduced IL-1beta staining in the orbito-frontal cortex in neuropathic mice. This study provides evidence that a single subcutaneous administration of ozone decreased neuropathic pain type behaviour, normalized the expression of pro-inflammatory caspases and reduced IL-1beta staining in the orbito-frontal cortex astrocytes in SNI mice. These preliminary data show that peripheral neuropathy induced over-expression of pro-inflammatory/pro-apoptotic caspases in the orbito-frontal cortex and that ozone, by mechanisms that are as yet unknown, can regulate the expression of the genes that play a pivotal role in the onset and maintenance of allodynia.

Ozonized autohemotransfusion does not affect arterial vasodilation in patients with peripheral arterial disease.

Ozonized autohemotransfusion has been used as a complementary therapy in patients with peripheral arterial disease (PAD). To determine whether ozone therapy could acutely modify artery vasodilatory capacity, a flow-mediated dilation test was performed at the brachial artery level before and after an ozonized autohemotransfusion in 16 patients with PAD, mean (± SD) age 55±1.8 years, and 14 healthy volunteers matched for age, sex and body mass index. Before ozonized autohemotransfusion, the mean baseline diameter of the brachial artery was higher in PAD patients than in healthy subjects (4.6±0.54 mm versus 3.6±0.54 mm, P<0.001) while mean flow-mediated brachial artery dilation and percentage of increase in flow were significantly lower in PAD patients than in controls (6.3±6.1% versus 11.8±2.4%, P<0.02; 433±61% versus 580±46%, P<0.02, respectively). No significant changes were observed after ozonized autohemotransfusion, indicating that ozonized autohemotransfusion does not modify endothelium-dependent ischemia-induced vascular reactivity.

Hyperbaric oxygen therapy prevents vascular derangement during zymosan-induced multiple-organ-failure syndrome.

OBJECTIVE: This study investigated the effects of hyperbaric oxygen (HBO) therapy on the cardiovascular alteration (e.g. mean arterial pressure, vascular reactivity of thoracic aorta rings changes) caused by zymosan in rats. DESIGN: Rats. SETTING: University research laboratory. INTERVENTION AND MEASUREMENTS: We investigated the effects of HBO therapy (2 ATA at the fourth and eleventh hours after study onset) on the cardiovascular alteration caused by zymosan (500 mg/kg, administered i.p. as a suspension in saline) in rats. Cardiovascular alterations were assessed 18 h after administration of zymosan and/or HBO therapy. RESULTS: Treatment of rats with HBO therapy attenuated the vasoplegic response to zymosan. In fact, the analysis of arterial pressure curves revealed no signs of vasoplegic shock. The aorta rings of animals treated with zymosan and HBO had a significantly increased contraction to norepinephrine (NE) and endothelin-1 (ET-1) and dilation to acetylcholine (ACh) compared with the zymosan group. The HBO therapy also attenuated the increase of malondialdehyde (MDA) levels caused by zymosan in the aorta. Immunohistochemical analysis for nitrotyrosine and for iNOS revealed positive staining in the aorta from zymosan-treated rats. The degree of staining for nitrotyrosine and iNOS was markedly reduced in tissue sections obtained from zymosan-rats treated with HBO therapy. CONCLUSION: This study provides the first evidence that HBO therapy attenuates the degree of zymosan-induced cardiovascular derangement in the rat.