Quercetin as a nephroprotector after warm ischemia: histomorphometric evaluation in a rodent model.

PURPOSE: To quantitatively evaluate the possible long-term protective effects of quercetin during renal warm ischemia. MATERIALS AND METHODS: Male rats were allocated into 4 groups: sham (S), sham quercetin (SQ), ischemia (I), and ischemia quercetin (IQ). Groups SQ and IQ received quercetin (50mg/kg) before and after surgery. Groups I and IQ had their left renal vessels clamped for 60 minutes. All animals were euthanized four weeks after the procedure, and serum urea and creatinine levels were measured. Renal weight and volume, cortex-non-cortex area ratio (C-NC), cortical volume (CV), glomerular volumetric density (Vv[glom]), volume-weighted glomerular volume (VWGV) and number of glomeruli per kidney (N[glom]) were evaluated by stereological methods. Results were considered statistically significant when p < 0.05. RESULTS: Serum urea levels in group I increased by 10.4% in relation to group S, but no differences were observed among the other groups. The C-NC of group I was lower than those of all other groups, and group IQ had similar results to sham groups. The Vv[glom] and N[glom] of group I were lower than those of group S (33.7% and 28.3%, respectively) and group IQ had no significant difference compared to the S group. CONCLUSIONS: Quercetin was effective as a nephroprotective agent in preventing the glomerular loss observed when the kidney was subjected to warm ischemia. This suggests that this flavonoid may be used preventively in kidney surgery, when warm ischemia is necessary, such as partial nephrectomy.

Evaluation of the effects of chronic stress applied from the prepubertal to the adult stages or only during adulthood on penile morphology in rats.

The present study aimed to evaluate the effects of chronic stress from the prepubertal to the adult stages or during adulthood on penile morphology in rats. The animals were immobilized in a cylinder for 2 h daily for a total of six weeks to simulate stress. Ten rats were exposed to stress stimulus beginning from the prepubertal age, while nine rats were exposed to stress stimulus only during adulthood. Animals were killed at 24 h after the last stress session for short-term evaluation (SP-S and SA-S), while other age-matched rats were sacrificed at 6 weeks after the last stress session for long-term evaluation (SP-L and SA-L). Age-matched animals were used as controls (CP-S, CA-S, CP-L and CA-L). After treatment, serum testosterone levels and areas of cavernosum structures were evaluated. We observed no changes in serum testosterone levels after stress treatment. Results revealed that the area of the corpus cavernosum without the tunica albuginea in animals in the SA-S group was 16% lower than that in the CA-S group. The smooth muscle was 31% lower in the SP-L group than in the SP-S group and 42% lower in the SA-S group than in the CA-S group. The elastic fiber system was 48% lower in the SP-L group than in the CP-L group and 59% lower in the SA-S group than in the CA-S group. Chronic stress promoted morphological changes in the rat penis and was significantly more pronounced when the stress occurred throughout the adulthood. Chronically applied single stress stimulus caused greater damage to the penis when induced directly during adulthood than when introduced before puberty to adulthood and could be associated with erectile dysfunction.

Immediate and Late Effects of Stress on Kidneys of Prepubertal and Adult Rats.

BACKGROUND/AIMS: Stress had been related to physiological and morphological alterations in different organs, however kidney morphology and function after stress conditions are not well-known. To evaluate the effects of chronic stress on renal morphology in prepubertal and adult rats, and to investigate if the effects of induced stress remain stable or worsen following removal of the stress stimuli. METHODS: Forty prepubertal rats (4 weeks old) and thirty six adult rats (10 weeks old) were used. Each age group was divided a into control group and a stressed group. Stressed animals were restrained in rigid tubes 2 hours per day for 6 weeks. Animals were euthanized 24 hours after the last stress stimulus for immediate evaluation (50% of the groups), and 6 weeks after the last stress stimulus for late evaluation (50% of the groups). Kidney weight and volume, cortical-medullar ratio, glomerular volumetric density, volume-weighted glomerular volume, and number of glomeruli per kidney were evaluated using the Image J software. RESULTS: Prepubertal stressed animals showed reduced kidney weight and volume, and increased cortical-medullar ratio in comparison to its control group when evaluated immediately. Furthermore, stressed prepubertal and adult animals evaluated immediately had reduced glomerular volumetric density. Most importantly, all stressed groups exhibited reduced number of glomeruli per kidney. Other analyzed parameters did not difeer significantly the groups. CONCLUSION: Chronic stress induced before and after puberty led to irreversible glomerular loss, however, renal impairment was interrupted by removal of the stress stimuli.

The sheep as a model for healing studies after partial nephrectomy.

BACKGROUND: The pig has been considered the best model for renal surgery. However, recent research has demonstrated that the kidney of pigs heals differently from that of humans. The objective of this study was to evaluate sheep as an alternative animal model for studying collecting system healing after laparoscopic partial nephrectomy. MATERIALS AND METHODS: The caudal pole of the left kidney was removed from eight female adult domestic sheep using laparoscopic partial nephrectomy. Monopolar energy was used for hemostasis only in the parenchyma, avoiding coagulation near the collecting system, which was left opened. After 14 d, all animals were euthanized, and their left kidney was removed. Serum levels of urea and creatinine were assessed preoperatively and postoperatively (on days 2, 6, 10, and 14), and peritoneal fluid samples were collected during necropsy for urea and creatinine evaluation. An ex vivo retrograde pyelogram was performed, and a retrograde injection of methylene blue ink was administered to evaluate urinary leakage. Samples from the operated pole were analyzed using histologic methods. RESULTS: During necropsy, an urinoma surrounding the operated kidney was observed in one animal. Peritoneal fluid levels of urea and creatinine were elevated. Retrograde pyelograms exhibited contrast-medium extravasation through the operated pole in all kidneys. The opened collecting system was also confirmed by methylene blue ink injection. The operated pole was covered by collagenous tissue and adhered to adjacent organs. CONCLUSIONS: Sheep should be considered as an adequate experimental model for research on collecting system healing after partial nephrectomy.

What is the effect of Tribulus terrestris on testicular morphology and sperm production? An experimental study in the rat model.

The objective of this study was to investigate whether treatment with Tribulus terrestris (Tt) has any impact on the testicular morphology and function in a rodent model. Twenty male rats were divided into a control group and a group receiving 100 mg kg-1 body weight of Tt supplementation. After 40 days of experiment, the animals were submitted to euthanasia; epididymal tail spermatozoa were collected; and spermatozoa concentration, motility, and viability were analyzed. In addition, testicles were collected and processed for histomorphometrical analyses. Data were compared using the Student's t-test and considered significant when P < 0.05. Spermatozoa concentration, motility, and viability showed no difference between the groups. Further, testicular weight and volume, seminiferous tubule diameter, tunica propria surface density, seminiferous epithelium surface density, and intertubular compartment surface density were statistically similar between the groups. However, seminiferous epithelium height and tubular lumen surface density were augmented in animals treated with Tt. Treatment with Tt does not cause a major impact on testicular morphology, promoting only subtle modifications. No difference on spermatozoa parameters was observed.

Current evidence for the involvement of sex steroid receptors and sex hormones in benign prostatic hyperplasia.

Benign prostatic hyperplasia (BPH) is a pathology that affects 50% of men over 50 years of age and 90% of men develop BPH in their eighth decade of life. In 2018, more than 1 billion men will be affected by this disease worldwide. However, the progression of BPH is highly complex and has been debated and studied for approximately four decades. Recent studies indicate that BPH can originate from the alteration of different hormone synthesis pathways, and that it is also linked to the function of hormone receptors. There is a close relationship between the progression of BPH and sexual hormones, such as progesterone, testosterone, dihydrotestosterone, and estrogen. The focus of this study was to characterize the interactions of these hormones and investigate the direct or indirect role of each sex hormone receptor in the progression of BPH. Although several studies have described the effects of these hormones on BPH, no conclusions have been drawn regarding their role in disease progression. Here, we present a literature review on the sexual receptors possibly involved in the progression of BPH.

Volume and Shape Assessment of Renal Radiofrequency Ablation Lesion.

OBJECTIVE: To evaluate the microscopic characteristics and quantify the volume of a radiofrequency ablation (RFA) lesion. METHODS: Ten male pigs were submitted to laparoscopic RFA. An RFA needle was introduced in the lower pole of the left kidney to create a lesion expected to be a sphere of 2.0 cm diameter. The animals were followed up for 21 days. Kidneys were weighed and the volume was assessed using Scherle's method. Cavalieri's principle was used to assess the RFA volume, and sphericity was calculated to assess RFA lesion. One sample t test was used to compare RFA volume with the volume of a sphere of 2.0 cm diameter, and sphericity to hypothetical values of a sphere and an icosahedron. Fragments of RFA region were histologically evaluated. RESULTS: Three animals developed postoperative complications and were excluded from the analyses. There was no difference in the mean weight and volume between right and left kidneys following RFA. The mean total volume of RFA injury was 3.44 cm3. There was no difference in the RFA volume in comparison with hypothetical volumes of a sphere and an icosahedron of 2.0 cm diameter. Sphericity of the RFA injury was not similar with a sphere; however, it was similar to an icosahedron. Histology revealed areas of coagulation necrosis, fibrosis, and inflammatory mononuclear infiltration. Areas with normal tissue were also observed. CONCLUSION: The volume of injury caused by RFA was as expected and its shape was comparable with an icosahedron. Microscopic evaluation revealed areas of normal-appearing tissue.

Glomerular Loss After Renal Radiofrequency Ablation Are Comparable to 30 Minutes of Warm Ischemia.

PURPOSE: To compare, with stereological methods, the glomerular loss in kidneys submitted to radiofrequency ablation (RFA) or warm ischemia. MATERIALS AND METHODS: Twenty-six male pigs were divided into three groups. Eight animals were allocated in the sham group, which was submitted to laparoscopic dissection of the left renal hilum, without renal ischemia. Eight animals were allocated in the ischemia group, which had the left renal hilum clamped for 30 minutes under laparoscopic access. Ten animals were submitted to RFA of the left kidney lower pole, under laparoscopic visualization. Animals were euthanized 21 days after surgery, when kidneys were collected. Fragments of the upper pole of the left kidney were processed for morphometric analysis. Right kidney was used as self-controls for each animal. Glomerular volumetric density (Vv[glom]); volume-weighted glomerular volume (VWGV); and glomerular density were quantified by stereological methods and compared by Student's t-test and one-way-analysis of variance with Dunnett's post-test. RESULTS: Three animals in the RFA group developed postoperative complications (Urinoma/Hydronephrosis) and were excluded from the analysis. No difference was found among the kidneys submitted to RFA and warm ischemia for all parameters. However, these kidneys showed lower Vv[glom] and glomerular density when compared to its self-controls (right kidneys), and when compared to sham-operated animals (p < 0.05). No difference was observed in regards to VWGV among the groups. CONCLUSION: RFA in pigs determines a significant reduction of glomerular density in the remaining parenchyma. This alteration was comparable to that observed in kidneys submitted to 30 minutes of warm ischemia.

Anatomical Relationship Between the Kidney Collecting System and the Intrarenal Arteries in the Sheep: Contribution for a New Urological Model.

Previous studies have demonstrated that the pig collecting system heals after partial nephrectomy without closure. Recently, a study in sheep showed that partial nephrectomy without closure of the collecting system resulted in urinary leakage and urinoma. The aim of this study was to present detailed anatomical findings on the intrarenal anatomy of the sheep. Forty two kidneys were used to produce tridimensional endocasts of the collecting system together with the intrarenal arteries. A renal pelvis which displayed 11-19 (mean of 16) renal recesses was present. There were no calices present. The renal artery was singular in each kidney and gave two primary branches one to the dorsal surface and one to ventral surface. Dorsal and ventral branches of the renal artery were classified based on the relationship between their branching pattern and the collecting system as: type I (cranial and caudal segmental arteries), type II (cranial, middle and caudal segmental arteries) or type III (cranial, cranial middle, caudal middle, and caudal segmental arteries). Type I was the most common branching pattern for the dorsal and ventral branches of the renal artery. The arterial supply of the caudal pole of the sheep kidney supports its use as an experimental model due to the similarity to the human kidney. However, the lack of a retropelvic artery discourages the use of the cranial pole in experiments in which the arteries are an important aspect to be considered.

The potential role of antioxidants in metabolic syndrome.

Metabolic syndrome (MS) is a constellation of risk factors that raise the risk for heart disease and other health problems, such as obesity. The clustering of metabolic abnormality is closely related to oxidative stress and inflammation, as well as the progression of atherosclerosis. Antioxidants are reducing agents which inhibit the oxidation of other molecules and can be used not only to prevent but also to treat health complications of MS and atherosclerosis. They can be ingested in the normal diet, since they are found in many food sources, or in supplement formulations. Herein, we aim to review the literature concerning the effect of antioxidants on MS. We focus on antioxidants with some evidence of action on this condition, like flavonoids, arginine, vitamin C, vitamin E, carotenoids, resveratrol and selenium. Experimental and clinical studies show that most of the above-mentioned antioxidants exhibit a wide range of effects in protecting the human body, especially in MS patients. However, the underlying mechanisms are not fully elucidated for most of these compounds. Also, some of them should be used with caution because their excess can be toxic to the body. In general, antioxidants (especially those present in foods) can be used by MS individuals because of their direct effect on oxidative stress. Additionally, they should be encouraged as part of a nutritional lifestyle change, since this is part of the therapy for all diseases involved in metabolic disorders.

How to Quantify Penile Corpus Cavernosum Structures with Histomorphometry: Comparison of Two Methods.

The use of morphometrical tools in biomedical research permits the accurate comparison of specimens subjected to different conditions, and the surface density of structures is commonly used for this purpose. The traditional point-counting method is reliable but time-consuming, with computer-aided methods being proposed as an alternative. The aim of this study was to compare the surface density data of penile corpus cavernosum trabecular smooth muscle in different groups of rats, measured by two observers using the point-counting or color-based segmentation method. Ten normotensive and 10 hypertensive male rats were used in this study. Rat penises were processed to obtain smooth muscle immunostained histological slices and photomicrographs captured for analysis. The smooth muscle surface density was measured in both groups by two different observers by the point-counting method and by the color-based segmentation method. Hypertensive rats showed an increase in smooth muscle surface density by the two methods, and no difference was found between the results of the two observers. However, surface density values were higher by the point-counting method. The use of either method did not influence the final interpretation of the results, and both proved to have adequate reproducibility. However, as differences were found between the two methods, results obtained by either method should not be compared.

Pneumoperitoneum induces morphological alterations in the rat testicle.

PURPOSE: To investigate the seminiferous tubule histological morphology after an 8 mmHg pneumoperitoneum in the rat model. METHODS: Fourteen rats were divided into two groups: a Sham group submitted to anesthesia and a pneumoperitoneum (Pp) group submitted to abdominal insufflation at 8 mmHg during three hours, followed by desuflation. All rats were killed after six weeks, testicles were collected and evaluated for the tubule diameter, germinative epithelium height and Johnsen´s score. Means were compared by using the Student's-t-test. RESULTS: The seminiferous tubule diameter was diminished by 11.3% in the group submitted to pneumoperitoneum (p<0.05). No significant difference was found among the groups when analyzing the epithelium height and Johnsen´s score. CONCLUSION: In the rat model, the seminiferous tubules present structural alterations when subjected to pneumoperitoneum of 8 mmHg during three hours.

Kidney healing after laparoscopic partial nephrectomy without collecting system closure in pigs.

OBJECTIVES: To access the kidney healing after laparoscopic partial nephrectomy without closing of the collecting system in pigs. METHODS: Fourteen pigs underwent left partial laparoscopic nephrectomy, with removal of 25% of the kidney length at caudal pole (n = 7) or at cranial pole (n = 7). Briefly, the surgical technique involved a transperitoneal laparoscopic access, en bloc vascular clamping of renal vessels, tissue excision with cold scissor and monopolar energy hemostasis of only the parenchyma, leaving the collecting system opened, with no insertion of a double-J catheter. The animals were clinically evaluated during 14 days, and afterward were killed. Serum levels of urea and creatinine were assessed prior and at different moments after surgery. Macroscopic necropsy analysis, a retrograde ex vivo pyelogram and a histologic study of the operated renal poles were performed. RESULTS: The animals did not show any postoperative clinical alterations. Serum levels of urea and creatinine showed a slight raising at the second postoperative day with gradual decreasing to preoperative levels. At necropsy, the abdominal cavity was normal, with normal quantity and aspect of peritoneal liquid. No signs of urine leakage were found. The operated renal pole was always involved by a perirenal fibrosis with adherences to adjacent organs. CONCLUSIONS: The pig kidney collecting system healed well without any kind of suture or internal drainage. Therefore, we concluded that the pig kidney is not an adequate model for research on which the collecting system healing is an important aspect to be considered.

Pneumoperitoneum induces morphological alterations in the rat testicle

PURPOSE:To investigate the seminiferous tubule histological morphology after an 8 mmHg pneumoperitoneum in the rat model. METHODS: Fourteen rats were divided into two groups: a Sham group submitted to anesthesia and a pneumoperitoneum (Pp) group submitted to abdominal insufflation at 8 mmHg during three hours, followed by desuflation. All rats were killed after six weeks, testicles were collected and evaluated for the tubule diameter, germinative epithelium height and Johnsen´s score. Means were compared by using the Student's-t-test. RESULTS:The seminiferous tubule diameter was diminished by 11.3% in the group submitted to pneumoperitoneum (p<0.05). No significant difference was found among the groups when analyzing the epithelium height and Johnsen´s score. CONCLUSION:In the rat model, the seminiferous tubules present structural alterations when subjected to pneumoperitoneum of 8 mmHg during three hours.