Can paricalcitol increase the effectiveness of n-acetylcysteine in contrast induced acute kidney prophylaxis in rats? A biochemical and histopathological study / ¿Puede el paricalcitol aumentar la eficacia de la n-acetilcisteína en la profilaxis renal aguda inducida por contraste en ratas? Un estudio bioquímico e histopatológico

SUMMARY: N-Acetylcysteine (NAC) is used for contrast induced acut kidney injury (CI-AKI) prophylaxis because of its antioxidant effects. Paricalcitol, which has reno-protective effects, is likely to provide a more effective prophylaxis when added to NAC treatment. The study was designed based on this hypothesis. The study was organised to include 4 groups each consisting of 7 rats. Group 1 was the control group, and Group 2 included rats with CI-AKI. Rats in Group 3 were administered NAC at a dose of 100 mg/kg via oral gavage once a day for 5 days. Rats in group 4 were administered paricalcitol at a dose of 0.4 mcg/kg once a day for 5 days in addition to NAC. CI-AKI was induced after the treatments in both groups. The study was terminated on the sixth day. Samples were collected from the rats' sera and kidney tissues to study oxidant and antioxidant parameters; kidney function tests were also studied. There were significant differences between the contrast nephropathy group (Group 2) and NAC and NAC+paricalcitol groups with respect to serum urea and creatinine levels. When the same groups were compared regarding oxidant (TOS-MDA) and antioxidant (TAC-Paraoxonase) parameters, we observed that the oxidant parameters increased in serum and kidney tissue samples with NAC use, and that effect was strengthened by the addition of paricalcitol to NAC treatment. However, despite increased antioxidant effectiveness, we observed no decrease in urea and creatinine levels when paricalcitol was added for CI-AKI in rats. There was no significant difference between Group 3 and Group 4. Paricalcitol provides a more potent antioxidant effect in both serum and kidney tissue samples when added to NAC treatment in rats with CI-AKI. Despite increased antioxidant parameters, however, paricalcitol does not provide a significant decrease in urea and creatinine levels.

RESUMEN: Debido a sus efectos atioxidantes la N- acetilcisteína (NAC) se usa para la profilaxis de la lesión renal aguda inducida por contraste (CI-AKI). Es probable que el paricalcitol, que tiene efectos renoprotectores, proporcione una profilaxis más eficaz cuando se agrega al tratamiento con NAC. En base a esta hipótesis el estudio fue diseñado para incluir cuatro grupos cada uno compuesto por siete ratas. El grupo 1 fue el grupo control y el grupo 2 incluyó ratas con CI-AKI. A las ratas del Grupo 3 se les administró NAC con una dosis de 100 mg/kg por sonda oral una vez al día, durante 5 días. A las ratas del grupo 4 se les administró paricalcitol a una dosis de 0,4 mcg/kg una vez al día durante 5 días, además de NAC. Se indujo CI-AKI después de los tratamientos en ambos grupos. El estudio finalizó el sexto día. Se recolectaron muestras de suero y tejidos renales de ratas para estudiar los parámetros oxidantes y antioxidantes; También se estudiaron las pruebas de función renal. Hubo diferencias significativas entre el grupo de nefropatía por contraste (Grupo 2) y los grupos NAC y NAC+paricalcitol con respecto a los niveles séricos de urea y creatinina. Cuando se compararon los mismos grupos con respecto a los parámetros oxidantes (TOS-MDA) y antioxidantes (TAC-Paraoxonase), observamos que los parámetros oxidantes aumentaron en muestras de suero y tejido renal con el uso de NAC, y ese efecto se vio reforzado por la adición de paricalcitol a tratamiento NAC. Sin embargo, a pesar de una mayor eficacia antioxidante, no observamos una disminución en los niveles de urea y creatinina cuando se agregó paricalcitol para CI-AKI en ratas. No hubo diferencias significativas entre el Grupo 3 y el Grupo 4. El paricalcitol proporciona un efecto antioxidante más potente tanto en muestras de suero como de tejido renal cuando se agrega al tratamiento con NAC en ratas con CI-AKI. Sin embargo, a pesar del aumento de los parámetros antioxidantes, el paricalcitol no proporciona una disminución sig- nificativa en los niveles de urea y creatinina.

The protective role of pomegranate juice against carbon tetrachloride-induced oxidative stress in rats.

Most pomegranate (Punica granatum Linn., Punicaceae) fruit parts are known to possess enormous antioxidant activity. The present study was carried out to determine the phenolic and flavonoid contents of Derik pomegranate juice and determine its effect against carbon tetrachloride (CCl4)-induced toxicity in rats. Animals were divided into four groups (n = 6): group I: control, group II: CCl4 (1 ml/kg), group III: CCl4 + pomegranate juice and group IV: CCl4 + ursodeoxycholic acid (UDCA). Treatment duration was 4 weeks, and the dose of CCl4 was administered once a week to groups II, III and IV during the experimental period. CCl4-treated rats caused a significant increase in serum enzyme levels, such as aspartate aminotransferase, alanine aminotransferase and total bilirubin, and decrease in albumin, when compared with control. Administration of CCl4 along with pomegranate juice or UDCA significantly reduces these changes. Analysis of lipid peroxide (LPO) levels by thiobarbutiric acid reaction showed a significant increase in liver, kidney and brain tissues of CCl4-treated rats. However, both pomegranate juice and UDCA prevented the increase in LPO level. Histopathological reports also revealed that there is a regenerative activity in the liver and kidney cells. Derik pomegranate juice showed to be hepatoprotective against CCl4-induced hepatic injury. In conclusion, present study reveals a biological evidence that supports the use of pomegranate juice in the treatment of chemical-induced hepatotoxicity.

The effect of low-level laser therapy on the healing of hard palate mucosa and the oxidative stress status of rats.

OBJECTIVE: The biostimulation effects of low-level laser therapy (LLLT) have been demonstrated recently. This study investigated the effects of LLLT on palatal mucoperiosteal wound healing and oxidative stress status in rats. MATERIAL AND METHOD: Forty-two male Wistar rats weighing 250-300 g were used in this study. A standardized full-thickness wound was created in the mucoperiosteum of the hard palates of the rats using a 3-mm-diameter biopsy punch. Treatment using a GaAlAs laser at a wavelength of 940 nm and a dose of 10 J/cm(2) was initiated after surgery and repeated on the 2nd, 4th, and 6th days post-surgery. Seven animals from each group were sacrificed on the 7th, 14th, and 21st days after surgery. Total antioxidant status and total oxidative status were measured in serum. RESULTS: The histopathological findings revealed reduced numbers of inflammatory cells on the 7th day, increased mitotic activity of fibroblasts on the 14th and 21st day, and the same degree of collagen synthesis and vascularization on the days 7, 14, and 21 in the LLLT group compared with the control group. No significant differences in total oxidative status and total antioxidant status were observed between the groups. CONCLUSION: LLLT using a GaAlAs laser at a wavelength of 940 nm and a dose of 10 J/cm(2) elicited a positive healing effect on palatal mucoperiosteal wounds likely via the induction of fibroblasts. The oxidative stress status was not affected by LLLT.

The effects of low-level laser therapy on palatal mucoperiosteal wound healing and oxidative stress status in experimental diabetic rats.

OBJECTIVE: The biostimulation effects of low-level laser therapy (LLLT) have recently been demonstrated. In this study, we aimed to investigate the effects of LLLT on palatal mucoperiostal wound healing and oxidative stress status in experimental diabetic rats. MATERIALS AND METHODS: Forty-two male Wistar rats that weighed 250-300 g were used in this study. Experimental diabetes was induced in all of the rats using streptozotocin. A standardized full thickness wound was made in the mucoperiosteum of the hard palates of the rats using a 3 mm biopsy punch. The rats were divided into groups: 1 (control group, non- irradiated), and 2 (experimental group, irradiated). Treatment using a GaAlAs laser at a wavelength of 940 nm and at dose of 10 J/cm(2) began after surgery, and was repeated on the 2nd, 4th, and 6th days post-surgery. Seven animals from each group were killed on the 7th, 14th, and 21st day after surgery. Biopsies were performed for the histological analysis and blood samples were collected by cardiac puncture for biochemical analysis. RESULTS: The histopathological findings revealed reduced numbers of inflammatory cells, and increased mitotic activity of fibroblasts, collagen synthesis, and vascularization in rats in group 2. The total oxidative status was significantly decreased in the laser-treated group on the 21st day. CONCLUSIONS: LLLT elicits a positive healing effect on palatal mucoperiostal wounds, and modulates the oxidative status in experimental diabetic rats.

Effect of lymphedema on the recovery of fractures.

BACKGROUND: Lymphedema delays the healing of any wound by negatively affecting its inflammatory period. Whether it affects bone healing in a similar negative manner is unknown. Therefore, we experimentally investigated the effect of lymphedema on fracture recovery. METHODS: We used thirty 200- to 250-g Sprague-Dawley rats for the experiment. The rats were randomly divided into two groups of 15 rats each for the experimental lymphedema and control groups. Lymphedema development was confirmed by measuring the circumference and diameter of the extremities together with lymphoscintigraphy. Twenty days after the development of lymphedema, a fracture model was created in both groups in the right tibia with mid-diaphyseal osteotomy and fixing with an intramedullary Kirschner wire. After 6 weeks, all rats were sacrificed and the callus tissue that formed along the osteotomy was compared between groups with respect to radiographic, histological, and biomechanical characteristics. RESULTS: The three-point bending test yielded an average stiffness value of 1227 N/mm (n = 6) in the control group and 284 N/mm (n = 7) in the experimental lymphedema group (P < 0.05). At the end of week 6, radiographic evaluation showed that solid knitting was obtained in the control group, whereas in the lymphedema group delayed or no knitting was observed. In the control group, histological investigation revealed normal callus morphology. Trabecular bone was normal and osteoblast and osteoclast activity was clearly evident. The bone was stained homogeneously with hematoxylin and eosin, and ossification was within normal limits. In the lymphedema group, however, the histological appearance was mostly that of scar tissue. In addition, osteoblast and osteoclast activity was much less visible or absent. CONCLUSIONS: Lymphedema negatively affected bone healing in rats. However, the mechanism of this negative effect and its occurrence in humans are still unknown. Further experimental and clinical studies are needed to support and extend our findings.

Effects of estrogen deficiency on tooth movement after force application: an experimental study in ovariectomized rats.

OBJECTIVE: The aim of this study was to investigate the effects of estrogen deficiency on tooth movement in ovariectomized rats. MATERIAL AND METHODS: Forty-two adult female Sprague-Dawley rats were assigned at random to one of the following groups: test group (n=20), ovariectomized rats (or estrogen-deficient rats); control group (n=22), non-ovariectomized rats. Two months after ovariectomy, expansion springs exerting 10 g of force were inserted between the upper central incisors in both groups. The amount of movement was measured daily until tooth movement began and then at intervals of 3 days. The rats were sacrificed 18 days after applying the expansion spring and histomorphometric analysis was performed along the left upper central incisor root towards the apex of the alveolar bone. RESULTS: The amount and speed of movement was observed to be greater in ovariectomized rats. On histomorphometric analysis, osteoblast and osteocyte counts on the pressure side were higher in the non-ovariectomized group than in the ovariectomized group (p<0.001). In contrast, the osteoclast count was significantly higher (p<0.01) in the ovariectomized group than in the non-ovariectomized group. The osteoblast and osteocyte counts were significantly higher (p<0.001) on tension side in the non-ovariectomized group than in the ovariectomized group. CONCLUSION: Estrogen deficiency increased orthodontic tooth movements but counts of osteoblasts, which are responsible for new bone formation, were lower in regions of tension and of pressure.

The effects of nitric oxide on the expression of cell adhesion molecules (ICAM-1, UEA-1, and tenascin) in rats with unilateral testicular torsion.

BACKGROUND/PURPOSE: The aim of this study was to determine the effects of nitric oxide (NO) on the expression of adhesion molecules in the early course of testicular I-R injury in rats. METHODS: Forty male Sprague-Dawley rats were separated into 4 groups, each containing 10 rats. A sham operation was performed in group 1 (control). In group 2 (I-R), after 6 hours of unilateral testicular torsion, 1-hour detorsion of the testis was performed. In group 3 (I-R/L-NAME), after performing the same surgical procedures as in group II, L-NAME was given for 30 minutes. In group 4 (I-R/Mol), after performing the same surgical procedure (torsion and detorsion) as in group II, molsidomine, an NO donor, was infused for 30 minutes. Then, ipsilateral orchiectomies were performed to measure the tissue levels of malondialdehyde (MDA) and NO and to make histologic examination. RESULTS: MDA values and the testicular injury score decreased and NO values increased in the I-R/Mol-treated group compared with other experimental groups. The tenascin expression in the interstitial space and basement membrane of the tubuli seminiferi were milder in the I-R/Mol group compared with that of the I-R and the I-R/L-NAME. The acrosomes of the spermatids in I-R and I-R/L-NAME groups were stained mildly by lectin. In the I-R and I-R/L-NAME groups, the interstitial spaces, basement membrane of the tubuli seminiferi, and sertoli and germinal cells in testicular tissue were stained intensely by ICAM-1. CONCLUSIONS: The expression of adhesion molecules such as tenascin, lectin, and ICAM-1 in the torted testicular tissue may be a pathophysiologic sign of inflammation. NO regulates adhesion molecules expression.