Background and Design.- Hyperoxaluria is a recognized cause of tubulointerstitial lesions in the kidney and it may contribute to chronic renal failure. Although the mechanism could not be well understood, in previous studies it was demonstrated that angiotensin II type I receptor blocker losartan was effective against the progression of tubulointerstitial lesions caused by hyperoxaluria. As far as we know, up to date the effects of hyperoxaluria on bladder were not studied although hyperoxaluric urine is stored in the bladder. In this study we tried to evaluate the damage of hyperoxaluria on bladder and epithelium, and action of losartan on these lesions: Two-month-old male Sprague-Dawley rats were randomized into four groups according to drinking water, 1-control animals given tap water only (n: 10 rats), 2-animals made hyperoxaluric by adding 1% ethylene glycol to the drinking water (n: 10 rats), 3-animals that were fed with 1% ethylene glycol plus 20 mgr/l angiotensin II type I receptor blocker losartan (n:10 rats), 4-animals fed with only losartan (n: 10 rats). In metabolic cages at the beginning and after four weeks, urine of the rats was collected for twenty-four hours and creatinine clearance, urinary albumin excretion, urinary pH and urinary oxalate levels were determined. Results were compared with the beginning levels and within the groups. Kruskal Wallis, ANOVA and Wilcoxan Rank probability tests were used as statistical methods and p<0.05 were considered as significant. Results.- There was no difference in urine oxalate excretion in ethylene glycol and ethylene glycol and losartan group. Renal functions significantly worsened in ethylene glycol group when compared with ethylene glycol and losartan group. Urine pH and nitrate levels were similar among the groups. Histological examination of the bladders revealed that in the second group, there were increased intracytoplasmic vacuolisation in the epithelium, epitheliums’ heights were also increased and in the connecting tissue there were increased bleeding points. Although some bleeding points in the connective tissue were seen in the third group, these were recovered by organization and there was increased mitosis at the connective tissue. Bladder’s height was decreased compared to group 1 and intrasitoplasmic vacuolization was not seen in this group. Bladder specimens had similar properties in control group and losartan group. Conclusion.- In this study we showed that hyperoxaluria causes epithelial damage in the bladder as in the tubulointerstitium. Losartan reverses this damage by increasing mitosis and prevents bladder epithelium. At this moment we do not know the relation between our hystochemical and hystologic result and clinical symptoms. Further investigations are needed on this subject.

Anjiotensin II tip I reseptor blokerlerinin hiperoksalurinin bobrek parankiminde olustur- dugu hasari geri dondurdugu gosterilmistir. Hi- peroksalurinin mesane uzerine etkisi ise bugu- ne kadar calisilmamistir. Hiperoksalurinin me- sane epiteli uzerine meydana getirdigi hasar ve losartanin bu olaylara etkisini inceledik. 40 adet erkek sican, icme sularina eklenen maddelere gore 4 gruba ayrildi. Normal su ile beslenen kontrol grubu (Grup 1), icme sularina %1 oraninda etilen glikol (EG) eklenerek hi- peroksaluri olusturulan Grup 2, icme sularina %1 EG ile anjiotensin II tip 1 blokeri olan lo- sartan eklenilen Grup 3 ve icme suyuna sadece 20 mg/lt losartan eklenen sicanlardan olusan Grup 4. Deneye baslamadan once ve dort haf- tanin sonunda hayvanlarin 24 saatlik idrarlari toplanilarak, idrar kreatinin, idrar oksalat duze- yi, mikroalbuminuri ve idrar pH’si bakildi. Bu degerler, baslangic degerleri ve gruplar arasin- da karsilastirildi. Cikarilan mesane dokulari histolojik olarak incelendi. Ikinci Grup ile 3. gruptaki sicanlarin idrar oksalat duzeylerinde bir farklilik gorulmemesi- ne ragmen ikinci grubun bobrek fonksiyonlari- nin anlamli olarak daha cok bozuldugu gorul- du. Histolojik incelenmelerde 2. gruptaki si- canlarin mesane epitellerinde intrasitoplazmik vakuolizasyonda artis, bag dokusunda kanama odaklari ve epitel kalinliginda artis gorulurken, 3. gruptaki sicanlarda butun bu degisikliklerin organize olarak tamir edildigi goruldu. Hiperoksaluri mesane epitelinde de hasara yol acmaktadir. Losartan bu hasari mitozu art- tirarak tamir etmektedir. Ancak, hiperoksaluri ile mesane epitelinde meydana gelen hasarin ne derece onemli oldugu bilinmemesine karsin, histokimyasal ve histolojik bulgularimiz ile mesane hastaliklari arasinda iliski kuracak ca- lismalara ihtiyac duyulmaktadir.

Oxidative stress and impaired bioactivity of nitric oxide (NO) play an important role in the organ pathogenesis and angiopathic complications of diabetes mellitus. In this study, we evaluated the effects of α-lipoic acid (ALA) on nitric oxide synthase (NOS) in lung tissues. ALA is a strong antioxidant. We wonder how it can affect oxidative stress and NO in the lung cells and vessels of diabetic rats. Wistar rats were divided into four groups; control, diabetic [65 mg/kg streptozotocin (STZ) for 15 days], STZ+ALA-treated (65 mg/kg ALA every 2 days for 15 days), and ALA-only-treated animals. At the end of the experimental period, lipid peroxidation, superoxide dismutase (SOD), and inducible NOS (iNOS) and endothelial NOS (eNOS) distribution were evaluated. Oxidative stress decreased with ALA in diabetic animals, and SOD also increased with ALA. iNOS and eNOS increased in diabetic animals, and ALA prevented iNOS increment in lung tissues. As a result, ALA can prevent some diabetic effects on the lungs and can also protect from vascular damages.

Leptin encoded by the obese gene exhibits various functions, especially in the regulation of food intake and energy expenditure. The aims of this study are to investigate some specific intestinal roles of leptin, i.e. the regulation of epithelial cell proliferation and the nitric oxide (NO) production in the small intestine from rats. A total of 32 male, 3 month old, Swiss albino rats were divided into 4 equal groups: animals received a single intraperitoneal injection of the recombinant leptin (200 mu g/kg) in the group 1 and of N-nitro-L-arginine methyl ester (L-NAME) (30 mg/kg), a nitric oxide synthase (NOS) inhibitor, in the group 2. Rats of the group 3 were treated by L-NAME (30 mg/kg) 15 minutes before the leptin injection (200 mu g/kg) and, in the group 4, rats received saline and served as controls. One hour after the last injection, blood samples were collected for the determination of plasma NO concentrations. After slaughtering, small intestines were harvested and treated for histological observations and immunohistochemistry in order to evaluate NOS expression and cell proliferation via proliferating cell nuclear antigen (PCNA) immunostaining. Significant morphological changes of epithelial cells evidencing by enlargement of cellular height and a marked increase of epithelial cell proliferation compared to the controls were induced by treatment with leptin alone or in combination with L-NAME. Furthermore, in leptin-treated rats, endothelial nitric oxide synthase (eNOS) synthesis was enhanced in goblet cells from the Lieberkuhn glands leading to a slight increase of plasma NO concentrations whereas inducible nitric oxide synthase (iNOS) expression remained unchanged. Although L-NAME alone or injected before leptin depressed plasma NO concentrations, modifications of epithelial cell chacteristics, a strong intensity of epithelial cell proliferation, as well an increased eNOS expression were also observed in the groups 2 and 3. These results demonstrate that leptin acts as a mitogene factor on epithelial cells of the small intestine and would have some medical indications. But even if eNOS was up-regulated in parallel, the molecular mechanisms leading to cell proliferation seem to be NO independent.

The roles of nitric oxide production and oxidative process were studied in mice infected with Toxocara canis and treated with aminoguanidine which is a specific inhibitor of inducible nitric oxide synthase (iNOS). Relations of nitric oxide synthase inhibition and tissue pathology were assessed by biochemical, histological and immunohistochemical methods. In experiments, Balb/c albino mice were inoculated with T. canis eggs either with or without aminoguanidine treatment or alone, at 24th, 48th hours and on 7th days. LPx and SOD values in liver tissue and plasma were measured. Liver and lung tissues were evaluated for the pathological lesions. The expression of eNOS and iNOS in both tissues were studied with immunohistochemistry in the same intervals. We observed significant differences between T. canis infected and aminoguanidine treated animals. Larval toxocarosis led to oxidative stress elevation in plasma. Microscopic examination of the liver histological sections revealed pathological lesions in the hepatic parenchyma in infected mice. In the mice received T. canis eggs plus aminoguanidine, the sinusoidal areas were enlarged. Histological lesions were more severe at 48 hours after infection. Numbers of eNOS and iNOS expressing epithelial cells were increased in the T. canis infected mice. The activities of eNOS and iNOS were also observed in the body of the larvae which have migrated to lung and liver. As a result, we have demonstrated that in vivo production of eNO and iNO during T. canis infection cause direct host damages and it is strongly related to the oxidative stress. We propose that larval NO can also be effective in larval migration, but it needs further investigation on distribution of NO in larvae.

After pelvic surgeries such as radical prostatectomy, two major complications--urinary incontinence and erectile dysfunction (ED) may occur. Etiologies for ED are multiple pathologic mediators/systems. Oxidative stress, which is known to be induced after surgical trauma, could be a cause of ED. The purposes of in this study are to investigate the effect of unilateral manipulation/ dissection and resection of the cavernous nerve (neurotomy) to NOS (nitric oxide synthase)-containing nerve fibers and pressure after electro stimulation in rat corpus cavernosum, and to determine whether these procedures would produce oxidative stress within rat cavernous tissue 3 weeks and 6 months after the operation. Male rats were divided into 5 groups. Rats in groups 1 and 2 underwent unilateral cavernous nerve manipulation and sacrificed 3 weeks and 6 months after the operation, respectively. Rats in groups 3 and 4 underwent unilateral neurotomy of a 5-mm. segment of the cavernous nerve, and they were sacrificed 3 weeks and 6 months after nerve ablation, respectively. Group 5 rats were control animals for biochemical analysis. Intracavernous pressure following electro stimulation reduced is significantly 3 weeks after unilateral resection, as compared to that of the manipulated nerve (P < 0.05), and it recovered 6 months after neurotomy. The recovery was also confirmed by NADPH (nicotinamide adenine dinucleotide phosphate) diaphorase staining in neurotomy groups. Lipid peroxidation, which is an indicater of oxidative stress, was determined by measuring thiobarbituric acid reacting substance (TBARS) levels and superoxide dismutase (SOD) activity. These markers indicated that unilateral cavernous nerve manipulation or resection produced oxidative stress within rat corpus cavernosum. Oxidative stress was more prominent 3 weeks after unilateral neurotomy (P < 0.05). Also, compared to the control animal group, oxidative stress was observed three weeks after manipulation of unilateral cavernous nerve (P < 0.05). Resection of the cavernous nerve caused more prominent oxidative stress than in the manipulation group. This study suggested, that unilateral cavernous neurotomy caused a decrease of intra cavernous pressure and NOS fibers in rat corpus cavernosum, and they recovered 6 months after neurotomy. Our data also provided evidence that neurotomy and manipulation of the cavernous nerve caused oxidative stress in rat corpus cavernosum and that oxidative stress was more prominent in the nerve resection group.

Diabetes-induced erectile dysfunction is one of the most prevalent complications of diabetes in males. alpha-Lipoic acid (ALA) and its reduced form, dihydrolipoic acid, are powerful antioxidants. Data strongly suggest that, because of its antioxidant properties, ALA is particularly suited to the prevention and/or treatment of diabetic complications that arise from overproduction of reactive oxygen and nitrogen. The aim of this study was to investigate the localization of nitric oxide synthetase (NOS) in normal and diabetic rat cavernous smooth muscles and to examine the effects of ALA on them. Rats were divided into four groups: control, diabetic, diabetic plus ALA, and ALA only. Penile tissues were taken 15 days after drug application and examined histochemically and immunohistochemically. Comparison of the control and diabetic groups revealed that the axons of nerve cells were not identified with Masson trichrome in the diabetic group, whereas in the control group NOS localization and immunostaining (endothelial NOS [eNOS]) were normal. Diabetic rats administered ALA showed improvement in Masson trichrome, nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) and eNOS localization compared with untreated diabetic rats. Although there was no difference between the control group and the group administered ALA only, we observed an increase in NADPH-d and eNOS. In erection, eNOS and neuronal NOS (nNOS) may have a significant role. In pathologic conditions, erectile dysfunction may occur as a result of an increase in inducible macrophage-type NOS (iNOS). ALA plays an important role in treatment of erectile dysfunction by decreasing iNOS and increasing other isoforms of NOS.

The aim of this study is to investigate the localization of NOS in normal and diabetic rats in the cavernose smooth muscles and to examine the effects of alpha-lipoic acid. Rats were divided into 4 groups as control, diabetic, diabetic +ALA applied, and only ALA. Tissues were examined by use of Masson trichrome, NADPH-d and eNOS. It was observed that ALA might play an important role in treatment of erectile dysfunction by decreasing iNOS and increasing the other isoforms of NOS.

Nitric oxide synthase (NOS) that uses NADPH as a cofactor is an enzyme which produces nitric oxide (NO) from L-arginine. Endothelial-derived (eNOS), inducible (iNOS) and neuronal (nNOS) nitric oxide synthase are 3 known isoforms. Endothelial NO regulates the vascular tonus and causes the dilatation of vessels, while NOS localized in the sarcolemma of striated muscle plays a role in the regulation of muscle hemodynamics. Many authors have found differences in NO production in some pathological conditions such as diabetes mellitus (DM), hypertension and atherosclerosis. In this study, NADPH-diaphorase (NADPH-d) was histochemically employed to explore any changes in NO production associated with the degree of DM, by detecting the enzyme in the muscle tissue. Diabetes was induced by injecting Swiss albino rats with 65mg/kg of streptozotosin (STZ). Two, 4, 6 and 12 weeks after the STZ injection, the spinotrapezius muscles of the animals were fixed in paraformaldehyde and NADPH-d histochemistry was applied to cryostat sections. Six and 12 weeks after DM, NOS increased both in the muscles and the endothelial cells of arterioles, being more prominent in the 12-week group in which the NADPH-d reaction was also localized in sarcoplasm together with the sarcolemma of muscle fibers than in controls. NOS was more abundant in the 2nd- and 3rd-order arterioles in diabetic animals than in controls. After the superfusion of the NW-nitro-L-Arginine Methyl Ester (L-NMA) that inhibits NOS, the NADPH-d reaction was still present in 12-week DM, while not in controls. ACh superfusion caused endothelial dilation and increased NO production in both the control and diabetic groups. This increase was observed to be more pronounced in diabetics than in controls. We also superfused sodium nitroprusside as a NO donor, and found resulting dilation in arterioles, with differences between the control and DM groups, the latter being more conspicuous.