Solubility of inert gases in dog blood and skeletal muscle

Solubility of H2, Ar, CH4 and SF6 was determined at 310 K (37 degrees C) in water, in saline (0.154 mol NaCl/l H2O), in plasma and whole blood of dogs, and in homogenates of the dog gastrocnemius muscle. The liquids were equilibrated with pure gases, and the dissolved gases were extracted and measured by gas chromatography as described previously (Meyer, M.: Pflügers Arch. 375, 161–165, 1978). In saline, the solubilities were 4% (SF6) to 15% (Ar) lower than in water. For dog blood the following mean values for the solubility coefficient (in mumol . 1(-1) . kPa-1) were found: for H2, 6.44; for Ar, 9.94; for CH4, 11.44; for SF6, 2.62. The red cell/plasma and the muscle/blood solubility ratios were near unity for H2, Ar and CH4 (ranging from 0.9 to 1.3); for SF6, however, they were much higher (about 2.1), apparently due to the high solubility of SF6 in hydrophobic substances (lipids).

The Therapeutic Effects of Oral Intake of Hydrogen Rich Water on Cutaneous Wound Healing in Dogs

This study explored the effects of drinking Hydrogen-rich water (HRW) on skin wound healing in dogs. Eight circular wounds were analyzed in each dog. The experimental group was treated with HRW thrice daily, while the control group was provided with distilled water (DW). The wound tissues of dogs were examined histopathologically. The fibroblasts, inflammatory cell infiltration, the average number of new blood vessels, and the level of malondialdehyde (MDA) and superoxide dismutase (SOD) activity in the skin homogenate of the wound was measured using the corresponding kits. The expressions of Nrf-2, HO-1, NQO-1, VEGF, and PDGF were measured using the real-time fluorescence quantitative method. We observed that HRW wounds showed an increased rate of wound healing, and a faster average healing time compared with DW. Histopathology showed that in the HRW group, the average thickness of the epidermis was significantly lower than the DW group. The average number of blood vessels in the HRW group was higher than the DW group. The MDA levels were higher in the DW group than in the HRW group, but the SOD levels were higher in the HRW group than in the DW group. The results of qRT-PCR showed that the expression of each gene was significantly different between the two groups. HRW treatment promoted skin wound healing in dogs, accelerated wound epithelization, reduced inflammatory reaction, stimulated the expression of cytokines related to wound healing, and shortened wound healing time.

Ionized Alkaline Water: New Strategy for Management of Metabolic Acidosis in Experimental Animals

Metabolic acidosis can occur as a result of either the accumulation of endogenous acids or loss of bicarbonate from the gastrointestinal tract or the kidney, which represent common causes of metabolic acidosis. The appropriate treatment of acute metabolic acidosis has been very controversial. Ionized alkaline water was not evaluated in such groups of patients in spite of its safety and reported benefits. So, we aimed to assess its efficacy in the management of metabolic acidosis in animal models. Two models of metabolic acidosis were created in dogs and rats. The first model of renal failure was induced by ligation of both ureters; and the second model was induced by urinary diversion to gut (gastrointestinal bicarbonate loss model). Both models were subjected to ionized alkaline water (orally and by hemodialysis). Dogs with renal failure were assigned to two groups according to the type of dialysate utilized during hemodialysis sessions, the first was utilizing alkaline water and the second was utilizing conventional water. Another two groups of animals with urinary diversion were arranged to receive oral alkaline water and tap water. In renal failure animal models, acid-base parameters improved significantly after hemodialysis with ionized alkaline water compared with the conventional water treated with reverse osmosis (RO). Similar results were observed in urinary diversion models as there was significant improvement of both the partial pressure of carbon dioxide and serum bicarbonate (P = 0.007 and 0.001 respectively) after utilizing alkaline water orally. Alkaline ionized water can be considered as a major safe strategy in the management of metabolic acidosis secondary to renal failure or dialysis or urinary diversion. Human studies are indicated in the near future to confirm this issue in humans.

H2 Mediates Cardioprotection Via Involvements of KATP Channels and Permeability Transition Pores of Mitochondria in Dogs

Inhalation of hydrogen (H(2)) gas has been shown to limit infarct size following ischemia-reperfusion injury in rat hearts. However, H(2) gas-induced cardioprotection has not been tested in large animals and the precise cellular mechanism of protection has not been elucidated. We investigated whether opening of mitochondrial ATP-sensitive K+ channels (mK(ATP)) and subsequent inhibition of mitochondrial permeability transition pores (mPTP) mediates the infarct size-limiting effect of H(2) gas in canine hearts. The left anterior descending coronary artery of beagle dogs was occluded for 90 min followed by reperfusion for 6 h. Either 1.3% H(2) or control gas was inhaled from 10 min prior to start of reperfusion until 1 h of reperfusion, in the presence or absence of either 5-hydroxydecanoate (5-HD; a selective mK(ATP) blocker), or atractyloside (Atr; a mPTP opener). Systemic hemodynamic parameters did not differ among the groups. Nevertheless, H(2) gas inhalation reduced infarct size normalized by risk area (20.6±2.8% vs. control gas 44.0±2.0%; p<0.001), and administration of either 5-HD or Atr abolished the infarct size-limiting effect of H(2) gas (42.0±2.2% with 5-HD and 45.1±2.7% with Atr; both p<0.001 vs. H(2) group). Neither Atr nor 5-HD affected infarct size per se. Among all groups, NAD content and the number of apoptotic and 8-OHdG positive cells was not significantly different, indicating that the cardioprotection afforded by H(2) was not due to anti-oxidative actions or effects on the NADH dehydrogenase pathway. Inhalation of H(2) gas reduces infarct size in canine hearts via opening of mitochondrial K(ATP) channels followed by inhibition of mPTP. H(2) gas may provide an effective adjunct strategy in patients with acute myocardial infarction receiving reperfusion therapy.

Therapeutic Effect of Hydrogen Injected Subcutaneously on Onion Poisoned Dogs

The purpose of this study was to investigate the therapeutic effect of hydrogen on the therapy of onion poisoned dogs. A total of 16 adult beagle dogs were divided into two groups (control and hydrogen) and all were fed dehydrated onion powder at the dose of 10 g/kg for three days. The dogs of the experimental group were given subcutaneous injection of 0.2 mL/kg of hydrogen for 12 days after making the poisoned model successful. Blood samples were collected before feeding onions, one day before injecting hydrogen, and 2 h after the injection of hydrogen on days 1, 3, 5, 7, 9, and 12. Control dogs were not treated with hydrogen. The levels of leukocyte production, anaemia, red blood cell degeneration which was reflected by the values of Heinz body count, haemolytic ratio, and oxidative products in hydrogen treated group were lower than in control dogs on some days. The capacity of medullary haematopoiesis that was based on reticulocyte counts, and the antioxidation in hydrogen group were higher compared with control group. However, the differences in renal function were not obvious in both groups. Accordingly, it was concluded that subcutaneous injection of hydrogen could alleviate the symptoms in onion poisoned dogs.

Protective effects of hydrogen on oxidative stress and liver function during CO2 pneumoperitoneum in dogs

The purpose of this study was to investigate the protective effects of hydrogen reducing ischemia-reperfusion injury during CO2 pneumoperitoneum on oxidative stress and liver function. Eighteen healthy Beagle dogs were divided into three groups. Dogs in the control group were subjected only to anesthesia for 90 min. The pneumoperitoneum group was subjected to the pressure of CO2 pneumoperitoneum with 12 mmHg intraabdominal pressure for 90 min. The hydrogen group was subjected to the pressure of CO2 pneumoperitoneum with 12 mmHg intra-abdominal pressure for 90 min after a subcutaneous injection of hydrogen gas (0.2 mL/kg) for 10 min. Blood samples were collected before the induction of pneumoperitoneum, as well as 2 h and 6 h after deflation, to evaluate oxidative stress and liver function in serum. Liver tissue samples were taken 6 h after deflation for histopathological examination. In comparison with group P, a milder histopathological change was found in group H2, and the levels of hepatic function and anti-oxidation in group H2 were higher. Hydrogen gas reduced liver ischemia-reperfusion injury due to CO2 pneumoperitoneum by reducing oxidative stress and improving liver function. Hydrogen gas therapy can be considered as a way to reduce liver ischemiareperfusion injury in laparoscopic surgery.

Protective effects of a hydrogen-rich preservation solution in a canine lung transplantation model

Background: Molecular hydrogen (H2) has protective effects against ischemia-reperfusion injury in various organs. Because they are easier to transport and safer to use than inhaled H2, H2-rich solutions are suitable for organ preservation. In this study, we examined the protective effects of an H2-rich solution for lung preservation in a canine left lung transplantation (LTx) model. Methods: Ten beagles underwent orthotopic left LTx after 23 hours of cold ischemia followed by reperfusion for 4 hours. Forty-five minutes after reperfusion, the right main pulmonary artery was clamped to evaluate the function of the implanted graft. The beagles were divided into two groups: control (CON group, n=5) and hydrogen (H2 group, n=5). In the CON group, the donor lungs were flushed and immersed during cold preservation at 4°C using ET-Kyoto solution, and in the H2 group, these were flushed and immersed using H2-rich ET-Kyoto solution. Physiological assessments were performed during reperfusion. After reperfusion, the wet-to-dry ratios were determined, and histological examinations were performed. Results: Significantly higher partial pressure of arterial oxygen and significantly lower partial pressure of carbon dioxide were observed in the H2 group than in the CON group (p=0.045 and p<0.001, respectively). The wet-to-dry ratio was significantly lower in the H2 group than in the CON group (p=0.032). Moreover, in histological examination, less lung injury and fewer apoptotic cells were observed in the H2 group (p<0.001 and p<0.001, respectively). Conclusions: Our results demonstrated that the H2-rich preservation solution attenuated ischemia-reperfusion injury in a canine left LTx model. (247 words).