Anxiety-like behavior induced by allergen is associated with decreased irregularity of breathing pattern in rats.

Allergic rhinitis (AR) is a chronic inflammatory disorder associated with a high prevalence of anxiety symptoms and respiratory disorders that adversely affect the quality of life. Studies have shown that allergen exposure induces anxiety-like behaviors. On the other hand, stress impairs the breathing pattern. However, the effect of stress on respiration and the relationship between anxiety-like behavior and stress-induced changes in breathing pattern has not been evaluated in AR. We assessed the impact of ovalbumin (OVA)-induced anxiety-like behaviors on stress-induced breathing pattern changes. Our findings showed that the allergic rhinitis induced by OVA challenge in sensitized rats induces anxiety-like behavior. Also, we found that stress decreases respiratory irregularity and increases respiratory variability, as well as the synchronization between IBI and RV time-series in AR animals. Moreover, in AR animals, we found a significant positive correlation between anxiety-like behavior and respiratory irregularity under non-stress conditions. Besides, a significant negative correlation was observed under stress conditions. The findings showed that anxiety-related behaviors may contribute to respiratory impairments under stress conditions in AR.

Effect of the conditioned medium of mesenchymal stem cells on the expression levels of P2X4 and P2X7 purinergic receptors in the spinal cord of rats with neuropathic pain.

Recent studies have shown that mesenchymal stem cells (MSCs) and their conditioned medium (CM) have potential therapeutic effects in animal models of neuropathic pain (NP). However, the mechanisms underlying these effects are not fully understood. Because of the leading involvement of purinergic receptors in the pathogenesis of NP, this study aimed to investigate the effect of MSCs-CM on the expression levels of P2X4 and P2X7 receptors in a rat model of NP induced by chronic constriction injury (CCI) of the sciatic nerve. CM was prepared from the rats' bone marrow-derived MSCs culture. After that, NP rats were treated by intraperitoneal injection of CM, or Dulbecco's modified Eagle's medium (DMEM) 1 day before and 7 and 11 days after CCI surgery. The NP status was assessed in the treated animals using behavioral tests, including mechanical allodynia and thermal hyperalgesia, on days - 1, 3, 6, 9, 12, and 15 of the study. At the end of the study (Day 15), the animals were sacrificed, and the relative gene expression of P2X4 and P2X7 receptors were measured in the spinal cord using quantitative real-time PCR. The results demonstrated that in the CM-treated NP rats, mechanical allodynia and thermal hyperalgesia were significantly reduced compared with the DMEM-treated group. In addition, the expression levels of P2X4 and P2X7 receptors were noticeably prevented in the CM-treated group than the control group. These findings indicate that the antinociceptive effects of CM in the NP rats are partly mediated through preventing the upregulation of P2X4 and P2X7 receptors in the spinal cord.

Ameliorative effect of cotreatment with the methanolic leaf extract of Urtica dioica on acute kidney injury induced by gentamicin in rats.

OBJECTIVE: Effects of cotreatment with Urtica dioica (UD) methanolic leaf extract on gentamicin (GM)-induced acute kidney injury were evaluated in rats. MATERIALS AND METHODS: Male Wistar rats (n=32) were separated into four groups. Gentamicin (100 mg/kg/day, IP) was injected for eight days with or without UD methanolic extract (200 mg/kg/day, gavage).  The renal blood flow (RBF) and systolic blood pressure of rats were recorded. Concentration of creatinine, blood urea nitrogen (BUN), sodium, and potassium and osmolarity were measured in the urine and plasma samples. Oxidative stress level was determined by assessment of the levels of antioxidant power (FRAP) and lipid peroxidation (MDA) in the renal tissue. The renal injury and histopathological changes in the kidney were determined by microscopic evaluations. RESULTS: Administration of UD extract along with GM, compared to GM group, significantly decreased the amounts of plasma creatinine and BUN, urinary sodium excretion, fractional excretion of sodium and potassium, and MDA levels but significantly increased creatinine clearance, urine osmolarity, renal blood flow and FRAP levels. CONCLUSION: The cotreatment of UD extract can attenuate renal injury of GM by reduction of oxidative stress, lipid peroxidation, and oxygen free radicals. The potential nephroprotective effects of UD extract are probably mediated via its antioxidant and anti-inflammatory activity.

Effects of Nitroglycerine on Renal Ischemia-Reperfusion Injury in Adult Male Rats.

BACKGROUND: Ischemia-reperfusion (I-R) leads to acute kidney injury (AKI). The present study investigated the effects of nitroglycerine (NG) on improving renal dysfunctions caused by I-R in rats. METHODOLOGY: Twenty-four rats were equally divided into four groups: (1) the control group, (2) the sham group, (3) the I-R group, and (4) NG-treated groups.NG (50 µg/kg) was injected intraperitoneally after induction of IR. I-R was induced through clamping of the bilateral renal artery and vein of both kidneys for 20 min followed by 24 h of reperfusion. RESULTS: NG significantly increased the creatinine clearance levels and renal blood flow rate (which was reduced by I-R). NG also significantly improved serum electrolytes (sodium and potassium) that were disordered by I-R. In addition, NG significantly offset impaired antioxidant defense mechanism and inhibited lipid peroxidation. CONCLUSIONS: The results show NG has a protective effect on renal tissue against AKI caused by I-R. These protective effects mediated through antioxidant activity and decrease of lipid peroxidation.

Ameliorative Effects of Zataria Multiflora Hydro-Alcoholic extract on Gentamicin Induced Nephrotoxicity in Rats.

BACKGROUND: Nephrotoxicity is the major side effects of aminoglycoside antibiotics such as gentamicin. The aim of this study was to investigate the therapeutic effects of Z.multiflora (ZM) hydroalcoholic extract on gentamicin-induced nephrotoxicity. METHODS: Twenty-eight male Wistar rats categorized into four groups: 1) the control group without injection, 2) the gentamicin treated group (100 mg/kg, i.p) 3) the gentamicin and Z. Multiflora treated group; Z. Multiflora extract(0.8 mg/ml in the drinking water) administered after gentamicin (100 mg/kg, i.p) 4) the normal saline and Z. Multiflora treated group; Z. Multiflora extract (0.8 mg/ml in the drinking water) administered after normal saline injection (2 ml/kg,i.p ). RESULTS: Post-treatment with ZM extract caused a significant reduction in the levels of plasma creatinine and blood urea nitrogen (BUN), absolute and fractional excretion of sodium, malondialdehyed (MDA) level in comparison to gentamicin group. In addition, ZM extract significantly increased creatinine clearance, urine osmolarity, and Renal blood flow (RBF) and the Ferric reducing ability of plasma (FRAP) level which had decreased compared to the control group as a result of treatment with gentamicin. CONCLUSION: The above result indicated that ZM extract improved renal toxicity of gentamicin via reducing oxidative stress, oxygen-free radicals, and lipid peroxidation.

Effects of Cobalamin (Vitamin B12) on Gentamicin Induced Nephrotoxicity in Rat.

Background The main side effect of gentamicin is nephrotoxicity. The effect of cobalamin (Cob) was investigated on gentamicin nephrotoxicity in rats. Methods Renal injury induced by i.p. injection of gentamicin (100 mg/kg) for 8 consecutive days. Cobalamin (6 mg/kg/day, i.p) treatment was done for 8 consecutive days as co-treatment and post-treatment protocol. Results Cobalamin significantly increased creatinine clearance levels and renal blood flow which were reduced by gentamicin. Also, cobalamin significantly improved serum electrolytes (sodium and potassium) levels which were disturbed by gentamicin. Cobalamin significantly compensated deficits in the antioxidant defense mechanisms, suppressed lipid per oxidation and ameliorated renal tissue damage mediated by gentamicin. Conclusion The results of the current study indicated that cobalamin effectively protected the kidney tissue against gentamicin induced acute nephrotoxicity in rats. The antioxidant and anti-inflammatory activities can be supposed the main factors responsible for the nephroprotective effect of cobalamin.

Oral administration of the aqueous extract of Rosmarinus officinalis in rats before renal reperfusion injury.

INTRODUCTION: Reperfusion injury leads to damage to the hemodynamic and functional parameters of the kidney. This study investigated the effects of oral administration of the aqueous extract of rosemary on improvement of changes induced by ischemia-reperfusion in rats. MATERIALS AND METHODS: Fourty male Sprague-Dawley rats were divided into 4 groups. One group was the control, rates in another group underwent sham operation, and 2 groups were exposed to reperfusion injury. Rats in one of the reperfusion groups was treated with 8% oral aqueous extract of rosemary (10 mL/kg/d) for 1 week (rosemary group), and the other received normal saline for the same period of time (reperfusion group). Reperfusion injury was induced by bilateral occlusion of the renal artery and vein for 30 minutes and reperfusion for 24 hours. Examination of oxidative stress was done, including measurement of malondialdehyde and ferric reducing antioxidant power in urine and blood samples. Histological studies were performed on excised kidneys. RESULTS: The comparison between the rosemary and reperfusion groups indicated significant reductions in the levels of plasma creatinine, blood urea nitrogen, and absolute urinary excretion of sodium in the rosemary group. Similarly, the rosemary group presented a significant decrease in malondialdehyde and a significant increase in ferric-reducing antioxidant power. Histopathological examinations showed significant reductions in vascular congestion and cells exfoliation in the rosemary group, in comparison with the reperfusion group. CONCLUSIONS: Oral administration of the aqueous extract of rosemary prior to ischemia-reperfusion is effective in reducing functional and histopathological complications associated with acute kidney failure.

Functional and developmental expression of a zebrafish Kir1.1 (ROMK) potassium channel homologue Kcnj1.

The zebrafish, Danio rerio, is emerging as an important model organism for the pathophysiological study of some human kidney diseases, but the sites of expression and physiological roles of a number of protein orthologues in the zebrafish nephron remain mostly undefined. Here we show that a zebrafish potassium channel is orthologous to the mammalian kidney potassium channel, ROMK. The cDNA (kcnj1) encodes a protein (Kcnj1) that when expressed in Xenopus laevis oocytes displayed pH- and Ba2+-sensitive K+-selective currents, but unlike the mammalian channel, was completely insensitive to the peptide inhibitor tertiapin-Q. In the pronephros, kcnj1 transcript expression was restricted to a distal region and overlapped with that of sodium­chloride cotransporter Nkcc, chloride channel ClC-Ka, and ClC-Ka/b accessory subunit Barttin, indicating the location of the diluting segment. In a subpopulation of surface cells, kcnj1 was coexpressed with the a1a.4 isoform of the Na+/K+-ATPase, identifying these cells as potential K+ secretory cells in this epithelium. At later stages of development, kcnj1 appeared in cells of the developing gill that also expressed the a1a.4 subunit.Morpholino antisense-mediated knockdown of kcnj1 was accompanied by transient tachycardia followed by bradycardia, effects consistent with alterations in extracellular K+ concentration in the embryo.Our findings indicate that Kcnj1 is expressed in cells associated with osmoregulation and acts as a K+ efflux pathway that is important in maintaining extracellular levels of K+ in the developing embryo.