Healing Process of Autogenous Bone Graft in Spontaneously Hypertensive Rats Treated With Losartan: An Immunohistochemical and Histomorphometric Study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Study of the ventral prostate of Wistar rats treated with Heteropterys tomentosa (A. Juss.)

Heteropterys tomentosa is a Brazilian plant traditionally used as an aphrodisiac and stimulant. Previous studies suggested possible androgenic and antioxidant effects after long term administration of H. tomentosa infusion. The aim of the present study was to evaluate the effects of this plant infusion on the rat ventral prostate: an androgen responsive organ. Wistar rats were treated, by gavage, with H. tomentosa roots infusion (treated group, n=6) or water (control group, n=6) for 56 days. Morphological, morphometrical and stereological analyses were employed to study the ventral prostate tissue, as well as androgen receptor and apoptotic cell staining. The ultrastructure of the prostatic epithelium was also analyzed. No alteration was observed in the stereological and morphometrical analyses. The pattern of androgen receptor expression and the apoptotic index were identical in the control and treated group. Ultrastructural analysis showed no alterations caused by H. tomentosa. These results suggested that treatment with H. tomentosa infusion, although considered a strong aphrodisiac, did not cause any major damage nor benefit to the prostate tissue.

Cardiovascular and autonomic alterations in rats with parkinsonism induced by 6-OHDA and treated with L-DOPA

Evaluate the effects caused by L-DOPA on cardiovascular and autonomic parameters in an animal model of Parkinsonism induced by 6-hydroxydopamine (6-OHDA).Adult male Wistar rats were subjected to bilateral microinfusion of 6-OHDA or saline (sham group) in the substantia nigra, and treated by gavage with L-DOPA or water for 7days after surgery. On the 6th day the rats were subjected to femoral artery catheterization for cardiovascular recording. Mean arterial pressure (MAP) and heart rate (HR) were evaluated at baseline and during head up tilt (HUT) protocol. Spectral analysis of cardiovascular variability was performed using the V2.4 CardioSeries software v2.4. The lesion was quantified by dopamine levels in the striatum.Dopamine levels in the striatum were decreased in 6-OHDA rats (sham: 4.79±0.49ng/mg; 6-OHDA: 1.99±0.68ng/mg) and were not recovered by Prolopa treatment. Baseline values of MAP and HR were not different between groups. HUT induced an increase in MAP and HR (ΔMAP: 17±1mmHg, ΔHR: 39±4bpm) that were attenuated in 6-OHDA and in Prolopa treated animals. At baseline, the systolic arterial pressure (SAP) variance was lower in the 6-OHDA and sham Prolopa groups. Spontaneous baroreflex sensitivity was higher at baseline in the 6-OHDA group as compared to all studied groups.Our data suggest that treatment with Prolopa did not interfere with cardiovascular variables at baseline. However, during HUT, the 6-OHDA and Prolopa control animals presented a lower cardiovascular compensation, suggesting a possible autonomic impairment in Parkinsonism induced by 6-OHDA.

Evaluation of testicular tissue of adult rats treated with cisplatin incorporated into the liposome

Cisplatin (CPL) is one of the most widely used and effective chemotherapeutic agents for the treatment of several human malignancies. However, it causes serious side effects, especially on reproduction. In order to reduce the undesirable effects caused by many drugs, liposomes have been used as a good system for drug delivery. The aim of this study was to investigate, for the first time, the effects of CPL incorporated into the dipalmitoyl phosphatidylcholine liposome (DPPC) on the testicular tissue of adult Wistar rats. The animals (n = 20) were distributed into four experimental groups: (a) control (distillated water); (b) liposome (DPPC, 1 mL), (c) cisplatin incorporated into liposome (CPL/DPPC), and (d) CPL (8 mg/kg body weight). The animals received a single intraperitoneal injection and were killed 10 days after each treatment for histopathological analysis of testes. The results showed that the testicular histomorphometric parameters in rats of DPPC and CPL/DPPC groups were similar to those of the control group. Meanwhile, rats of the CPL-treated group showed a variety of morphological alterations, including atrophy of seminiferous tubules and presence of multinucleated cells in the germinal epithelium. The incorporation of CPL into the liposome had no influence on the testicular weight or any other stereological parameters, but it was beneficial in maintaining the body weight of the animals. In conclusion, the liposome suppressed the cytotoxic effects caused by cisplatin in the testes of rats, suggesting a possible use in chemotherapy against cancer to reduce the side effects seen on reproduction.

Mast cell concentration and skin wound contraction in rats treated with Brazilian pepper essential oil (Schinus terebinthifolius Raddi)

PURPOSE: To evaluate wound contraction and the concentration of mast cells in skin wounds treated with 5% BPT essential oil-based ointment in rats. METHODS: Twenty rats, male, of adult age, were submitted to skin surgery on the right (RA) and left antimeres (LA) of the thoracic region. They were divided into two groups: control (RA - wounds receiving daily topical application of vaseline and lanolin) and treated (LA - wounds treated daily with the topical ointment). The skin region with wounds were collected at days 4, 7, 14 and 21 after surgery. Those were fixed in 10% formaldehyde and later processed for paraffin embedding. Sections were obtained and stained by H.E for histopathology analysis. The degree of epithelial contraction was measured and mast cell concentration were also evaluated. RESULTS: The treated group showed higher mast cell concentrations (p<0.05) associated with increased contraction at day 7 and 14 respectively. CONCLUSION: Ointment containing 5% Brazilian pepper tree oil increases mast cell concentration and promotes skin wound contraction in rats.

Alveolar bone dynamics in osteoporotic rats treated with raloxifene or alendronate: confocal microscopy analysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Analysis of experimental tendinitis in rats treated with laser and platelet-rich plasma therapies by Raman spectroscopy and histometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sodium intake, brain c-Fos protein and gastric emptying in cell-dehydrated rats treated with methysergide into the lateral parabrachial nucleus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Changes in the oxidative stress biomarkers in liver of streptozotocin-diabetic rats treated with combretum lanceolatum flowers extract

Aims: The study investigated the in vivo antioxidant activity and the in vitro radical scavenging capacity of the Combretum lanceolatum Pohl (Combretaceae) flowers ethanolic extract (ClEtOH) in streptozotocin-diabetic rats. Place and Duration of Study: Department of Chemistry, Federal University of Mato Grosso, Cuiabá, Brazil; between February 2012 and December 2012. Methodology: Male Wistar rats were divided into four groups: Normal rats treated with water/vehicle (N); diabetic rats treated with water (DC); diabetic rats treated with 250 mg/kg (DT250) or with 500mg/kg (DT500) of ClEtOH. After 21 days of treatment, liver samples were used for the analysis of the oxidative stress biomarkers and activity of antioxidant enzymes. In vitro radical scavenger capacity was investigated by the following methods: DPPH radical scavenging, ABTS radical cation decolorization and crocin bleaching assays. Results: Significant oxidative stress was observed in liver of DC, since the malondialdehyde (MDA, biomarker of lipoperoxidation) levels were increased in comparison with N. Increased activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were also observed in DC, which could represent a compensatory mechanism against oxidative stress. Glutathione (GSH) levels were lower and similar between N and DC. The MDA levels were significantly decreased in liver of rats from DT250 and DT500, reaching levels similar those of N, suggesting that ClEtOH prevented lipoperoxidation. The treatment of diabetic rats with ClEtOH also increased the GSH levels, as well as increased the GSH-Px activity, and did not change the SOD activity. The results of in vitro radical scavenging capacity indicated that ClEtOH is highly active. Conclusion: These findings indicate that ClEtOH has antioxidant properties in liver of diabetic rats, decreasing lipoperoxidation and increasing the endogenous antioxidant responses. Both the antihyperglycemic effect and the capacity to scavenge free radicals may be related to the antioxidant activity of ClEtOH in diabetes.

Assessment of micronucleus frequency in the peripheral blood of female rats in persistent estrus treated with selective estrogen receptor modulators

The aim of this study was to evaluate micronucleus (MN) frequency in polychromatic erythrocytes (PCE) of female rats in persistent estrus (a model developed to mimic polycystic ovary syndrome) treated with selective estrogen receptor modulators (SERMs, tamoxifen, and raloxifene). Forty female Wistar-Hannover rats were divided into four groups of 10 animals each: Group I (normally cycling rats) and Group II (persistent estrus) both received only vehicle, while Group III (persistent estrus) was treated with tamoxifen (250 mu g/animal/day) and Group IV (persistent estrus) was treated with raloxifene (750 mu g/animal/day). Tamoxifen and raloxifene were given by oral gavage beginning on postnatal day 90 and continuing for 30 consecutive days. Peripheral blood samples were collected from tails 1 day following the last exposure. Blood smears were made on glass slides and stained with 10% Giemsa solution. ANOVA and a Tukey post-hoc test were used for data analysis. Mean percentages of MN were 1.82 +/- 0.13, 5.20 +/- 0.24, 3.32 +/- 0.13, and 3.04 +/- 0.12 in Groups I, II, III, and IV, respectively. The results indicate that tamoxifen and raloxifene similarly reduced the formation of MNPCE of female rats in persistent estrus (P < 0.0001 for Groups III and IV vs. Group II), using the dosages and time periods applied in the present study. The data suggest possibly antimutagenic effects of SERMs under high levels of estrogens. The findings also suggest that this is an interesting animal model for studying the genotoxicity of estrogens. Environ. Mol. Mutagen. 2012. (C) 2011 Wiley Periodicals, Inc.

Histomorphometric analysis of inflammatory response and necrosis in re-implanted central incisor of rats treated with low-level laser therapy

Low-level laser therapy is a tool employed in the management of post-operative inflammation process and in the enhancement of reparative process. The aim of the study was to perform histological evaluation of dental and periodontal ligament of rats central upper-left incisor teeth re-implanted and irradiated with low-level laser (InGaAl, 685 nm, 50 J/cm(2)) 15, 30, and 60 days after re-implantation. Seventy-two male rats had the central upper left incisor removed and kept for 15 min on dry gauze before replantation. Laser was irradiated over the root surface and empty alveolus prior replantation and over surrounding mucosa after the re-implantation. After histological procedures, all slices were analyzed regarding external resorption area and histological aspects. We observed an increase of root resorption (p < 0.05) in the control group compared to the laser group at 15, 30, and 60 days. These results showed that the laser groups developed less root resorption areas than the control group in all experimental periods. Additionally, histological analysis revealed less inflammatory cells and necrotic areas in laser groups.

Effects of creatine supplementation on muscle wasting and glucose homeostasis in rats treated with dexamethasone

We aimed to investigate the possible role of creatine (CR) supplementation in counteracting dexamethasone-induced muscle wasting and insulin resistance in rats. Also, we examined whether CR intake would modulate molecular pathways involved in muscle remodeling and insulin signaling. Animals were randomly divided into four groups: (1) dexamethasone (DEX); (2) control pair-fed (CON-PF); (3) dexamethasone plus CR (DEX-CR); and (4) CR pair-fed (CR-PF). Dexamethasone (5 mg/kg/day) and CR (5 g/kg/day) were given via drinking water for 7 days. Plantaris and extensor digitorum longus (EDL) muscles were removed for analysis. Plantaris and EDL muscle mass were significantly reduced in the DEX-CR and DEX groups when compared with the CON-PF and CR-PF groups (P < 0.05). Dexamethasone significantly decreased phospho-Ser(473)-Akt protein levels compared to the CON-PF group (P < 0.05) and CR supplementation aggravated this response (P < 0.001). Serum glucose was significantly increased in the DEX group when compared with the CON-PF group (DEX 7.8 +/- A 0.6 vs. CON-PF 5.2 +/- A 0.5 mmol/l; P < 0.05). CR supplementation significantly exacerbated hyperglycemia in the dexamethasone-treated animals (DEX-CR 15.1 +/- A 2.4 mmol/l; P < 0.05 vs. others). Dexamethasone reduced GLUT-4 translocation when compared with the CON-PF and CR-PF (P < 0.05) groups and this response was aggravated by CR supplementation (P < 0.05 vs. others). In conclusion, supplementation with CR resulted in increased insulin resistance and did not attenuate muscle wasting in rats treated with dexamethasone. Given the contrast with the results of human studies that have shown benefits of CR supplementation on muscle atrophy and insulin sensitivity, we suggest caution when extrapolating this animal data to human subjects.

Association between hepatic cholesterol and oleic acid in the liver of rats treated with partially hydrogenated vegetable oil

Objective The aim of the present study was to investigate the lipid profiles of the hepatic and adipose tissues of Wistar rats treated for 21 days with a diet high in saturated fat (high saturated fat, n=6) or high in hydrogenated fat, that is, having 50% partially hydrogenated vegetable oil in its composition (high hydrogenated fat, n=6), and compare them to those of a control group (control group, n=6). Methods Adipose tissue and total hepatic fat were higher in the saturated fat group than in the hydrogenated fat group. Hepatic lipid peroxidation was greatest in the saturated fat group, with consequent lower hepatic vitamin E and A levels. In contrast, serum vitamin A was highest in the saturated fat group. Analysis of hepatic lipid fractions found more cholesterol and less high density lipoprotein-cholesterol in the hydrogenated fat group. The hydrogenated fat group had the highest levels of triacylglycerols, followed by the saturated fat group. Results Significant amounts of trans fatty acids were detected in the hepatic and adipose tissues of the hydrogenated fat group. Among the identified fatty acids, 18:1n9 had a higher positive association with hepatic cholesterol and triacylglycerols, and a higher negative association with high density lipoprotein-cholesterol. Partially hydrogenated vegetable oil promotes greater accumulation of cholesterol and triacylglycerols in the liver than saturated fats. Conclusion Trans fatty acids were incorporated into hepatocytes and adipocytes in a highly efficient manner.

Glycosaminoglycan profiles in the uterus of adult ovariectomized rats treated with estrogen and progestagen

Objectives: To evaluate the effects of conjugated equine estrogens (CE) alone or in combination with medroxyprogesterone acetate (MPA) on glycosaminoglycans (GAGs) in the cervix and horns of the rat uterus. Study design: Thirty days after ovariectomy, adult rats were randomly divided into four groups: Cl, control (treated with drug vehicle); GII CE (50 mu g/kg per day); GIII, MPA (0.2 mg/kg per day), and GIV, CE + MPA (doses as in GII and Gill). Drugs and vehicle were given by gavage during 28 days. Afterwards the animals were anesthetized, the cervix and uterine horns were dissected out and the middle portion fixed in 10% formaldehyde solution; other portions were fixed in acetone for histological examination and glycosaminoglycan quantification, respectively. Agarose gel electrophoresis was used for sulfated GAG analyses, and hyaluronic acid was assayed with an ELISA-like method. Statistical analysis was done by the Student's t test and the Tukey-Kramer test (P < 0.05). Results: The cervix and uterine horn structures presented signs of atrophy in the control group (GI). The other groups, mainly groups III and IV, had histological aspects of proliferation. In all groups the concentration of sulfated GAGs (especially dermatan sulfate) was higher than that of non-sulfated GAGs, both in cervix and in uterine horns. Estrogens increased sulfated GAG concentration at the cervix and the horn, whereas in uterine horns the amounts of sulfated GAGs were decreased after estrogens plus MPA treatment. The concentration of hyaluronic acid in uterine horns was higher than in cervices. Conclusions: The profiling and amounts of glycosaminoglycans in the two portions of the rat uterus are uneven. Dermatan sulfate occurs in higher concentrations in both cervix and uterine horns. Sulfated GAGs in rat cervix were increased by estrogens plus MPA, but were decreased by MPA alone in uterine horns. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

The inhibition of bone resorption in rats treated with (-)-menthol is due to its metabolites

(-)-Menthol, a monoterpene from Mentha species (Lamiaceae), has been shown to inhibit bone resorption in vivo by an unknown mechanism. In the present study, plasma and urine profiling in rats determined by GC/MS demonstrate that (-)-menthol is extensively metabolized, mainly by hydroxylation and carboxylation, and excreted in the urine, in part as glucuronides. In plasma, very low concentrations of (-)-menthol metabolites were detected after a single dose of (-)-menthol, whereas after repeated treatment, several times higher concentrations and long residence times were measured. In contrast, the elimination of unchanged (-)-menthol was increased by repeated treatment. (-)-Menthol, at concentrations found in plasma, did not inhibit bone resorption in cultured mouse calvaria (skull). However, the neutral metabolites of (-)-menthol, extracted from urine of rats fed with (-)-menthol, inhibited bone resorption in vitro, the concentrations being at plasma level or higher. These results suggest that not (-)-menthol itself, but one or several of its neutral metabolites inhibit the bone resorbing cells in vivo.