Calcitriol Reduces the Inflammation, Endothelial Damage and Oxidative Stress in AKI Caused by Cisplatin.

Cisplatin treatment is one of the most commonly used treatments for patients with cancer. However, thirty percent of patients treated with cisplatin develop acute kidney injury (AKI). Several studies have demonstrated the effect of bioactive vitamin D or calcitriol on the inflammatory process and endothelial injury, essential events that contribute to changes in renal function and structure caused by cisplatin (CP). This study explored the effects of calcitriol administration on proximal tubular injury, oxidative stress, inflammation and vascular injury observed in CP-induced AKI. Male Wistar Hannover rats were pretreated with calcitriol (6 ng/day) or vehicle (0.9% NaCl). The treatment started two weeks before i.p. administration of CP or saline and was maintained for another five days after the injections. On the fifth day after the injections, urine, plasma and renal tissue samples were collected to evaluate renal function and structure. The animals of the CP group had increased plasma levels of creatinine and of fractional sodium excretion and decreased glomerular filtration rates. These changes were associated with intense tubular injury, endothelial damage, reductions in antioxidant enzymes and an inflammatory process observed in the renal outer medulla of the animals from this group. These changes were attenuated by treatment with calcitriol, which reduced the inflammation and increased the expression of vascular regeneration markers and antioxidant enzymes.

Effect of Calcitriol on the Renal Microvasculature Differentiation Disturbances Induced by AT1 Blockade During Nephrogenesis in Rats.

Alterations in the renal vasculature during fetal programming can cause disturbances in renal structure and function that persist into adulthood. Calcitriol can affect cellular differentiation and proliferation, and promote endothelial cell maintenance, each of which is a key event in nephrogenesis. Calcitriol is a negative endocrine regulator of the renin gene. Rats exposed to renin-angiotensin system (RAS) antagonists during lactation have been shown to develop renal disorders, which demonstrated that the RAS may play an important role in mammalian kidney development. We evaluated the effects of calcitriol administration on losartan [angiotensin II receptor antagonist (ANGII), AT1]-induced changes in renal differentiation in rats during lactation. Rats treated with losartan showed alterations in renal function and structure that persisted into adulthood. These disruptions included hydronephrosis, papillary atrophy, endothelial dysfunction, and aberrant endothelial structure. These changes were mitigated by treatment with calcitriol. The results of our study showed that animals exposed to AT1 blockade during lactation exhibited altered renal microvasculature differentiation in adulthood that was attenuated by treatment with calcitriol.

Increased hypothalamic hydrogen sulphide contributes to endotoxin tolerance by down-modulating PGE2 production.

AIM: Whereas some patients have important changes in body core temperature (Tb) during systemic inflammation, others maintain a normal Tb, which is intrinsically associated to immune paralysis. One classical model to study immune paralysis is the use of repeated administration of lipopolysaccharide (LPS), the so-called endotoxin tolerance. However, the neuroimmune mechanisms of endotoxin tolerance remain poorly understood. Hydrogen sulphide (H2 S) is a gaseous neuromodulator produced in the brain by the enzyme cystathionine ß-synthase (CBS). The present study assessed whether endotoxin tolerance is modulated by hypothalamic H2 S. METHODS: Rats with central cannulas (drug microinjection) and intraperitoneal datalogger (temperature record) received a low-dose of lipopolysaccharide (LPS; 100 µg kg-1 ) daily for four consecutive days. Hypothalamic CBS expression and H2 S production rate were assessed, together with febrigenic signalling. Tolerant rats received an inhibitor of H2 S synthesis (AOA, 100 pmol 1 µL-1 icv) or its vehicle in the last day. RESULTS: Antero-ventral preoptic area of the hypothalamus (AVPO) H2 S production rate and CBS expression were increased in endotoxin-tolerant rats. Additionally, hypothalamic H2 S inhibition reversed endotoxin tolerance reestablishing fever, AVPO and plasma PGE2 levels without altering the absent plasma cytokines surges. CONCLUSION: Endotoxin tolerance is not simply a reflection of peripheral reduced cytokines release but actually results from a complex set of mechanisms acting at multiple levels. Hypothalamic H2 S production modulates most of these mechanisms.

Propargylglycine decreases neuro-immune interaction inducing pain response in temporomandibular joint inflammation model.

The mechanisms underlying temporomandibular disorders following orofacial pain remain unclear. Hydrogen sulfide (H2S), a newly identified gasotransmitter, has been reported to modulate inflammation. Cystathionine γ-lyase (CSE) is responsible for the systemical production of H2S, which exerts both pro- and antinociceptive effects through inflammation. In the current study, we investigated whether the endogenous H2S production pathway contributes to arousal and maintenance of orofacial inflammatory pain, through the investigation of the effects of a CSE inhibitor, propargyglycine (PAG), in a rat CFA (Complete Freund Adjuvant)-induced temporomandibular inflammation model to mimic persistent pain in the orofacial region. For this, rats received either CFA or saline in the temporomandibular joints (TMJs), and after 3 or 14 days, they received a single injection of PAG or saline and were evaluated for nociception with the von Frey and formalin test. Also, pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß) were analyzed in TMJs and trigeminal ganglion (TG). In this last one, glial cells reactivity was also verified. Endogenous H2S production rate were measured in both, TMJ and TG. Our results indicated decreased allodynia and hyperalgesic responses in rats submitted to CFA after injection of PAG. Moreover, PAG inhibited leucocyte migration to temporomandibular synovial fluid after 3 and 14 days of inflammation. PAG was able to reduce levels of CBS, CSE, TNF-α, and IL-1ß in the TMJ and TG, after 13 days of CFA injection. The observed increased activation of glial cells in the trigeminal ganglia on the 14th day of inflammation can be prevented by the highest dose of PAG. Finally, CBS and CSE expression, and endogenous H2S production rate in the TMJ and TG was found higher in rats with persistent temporomandibular inflammation compared to rats injected with saline and PAG was able to prevent this elevation. Our results elucidated the molecular mechanisms by which H2S exerts its pro-inflammatory and pro-nociceptive role in the orofacial region by alterations in both local tissue and TG.

Oral administration of powdered dried rhizomes of Curcuma longa L. (turmeric, Zingiberaceae) is effective in the treatment of doxorubicin-induced kidney injury in rats.

Curcumin is a polyphenol present in the rhizomes of the species Curcuma longa L. ("turmeric," Zingiberaceae), which has been used for centuries as an anti-inflammatory. We aimed to evaluate the anti-inflammatory effects of C. longa in renal injury induced by doxorubicin (DOX, 3.5 mg.kg-1 IV). We studied four groups of Wistar rats: two groups with DOX-induced kidney injury, one fed with standard food and another with standard food mixed with C. longa (5 mg.g-1 ). Two other control groups without kidney injury were fed with the same foods. We measured albuminuria, body weight, and food intake every 2 weeks. After 8 weeks, treatment with C. longa did not change albuminuria, but it significantly attenuated the excretion of urinary inflammatory markers monocyte chemoattractant protein-1 (MCP-1) and transforming growth factor-ß (TGF-ß) and significantly attenuated immunostaining for desmin, vimentin, and ED-1+ cells in renal tissues of rats with DOX-induced kidney injury. In addition, treatment with C. longa resulted in significantly lower glomerular and tubule interstitial injury scores, compared with that in the DOX-STD group. In conclusion, administration of powdered rhizomes of C. longa for 8 weeks to rats with DOX-induced kidney injury did not reduce albuminuria but led to a significant decrease in urinary inflammatory markers MCP-1 and TGF-ß and decreased histopathological alterations and immunostaining for desmin, vimentin, and ED-1+ cells kidneys tissues.

Previous Exercise Effects in Cisplatin-Induced Renal Lesions in Rats.

BACKGROUND/AIMS: Physical training has beneficial effects on endothelial function and can influence the regeneration of the endothelial cell. We investigated the effect of physical training on cisplatin (CP)-induced acute kidney injury and assessed the impact of training on endothelial structure and function, and on the inflammatory processes in rats. METHODS: We injected male Wistar rats subjected to previous physical training in treadmill running (trained, TR) or not (sedentary, SED) with CP (5 mg/kg) (TR+CP and SED+CP groups, respectively). Five days after the injections, blood and urine samples were collected to evaluate renal function and kidneys were harvested for morphological, immunohistochemical, enzyme-linked immunosorbent assay, and analysis of nitric oxide (NO) levels. RESULTS: Rats treated with CP showed increased levels of plasma creatinine and sodium and potassium fractional excretion. These alterations were associated with increase in tubulointerstitial lesions and macrophage number, reduction of endothelial cells, and increased VEGF, vimentin, and α-smooth muscle actin expression in the outer renal medulla in the SED+CP group. We also found increased levels of renal IL-1ß and increased excretion of monocyte chemoattractant protein-1 and transforming growth factor-ß compared with controls. These changes were milder in trained rats, associated with increased levels of renal tissue NO, and increased expression of p-eNOS and stromal cell-derived factor-1α (a chemokine involved in kidney repair) in the kidneys of CP-injected trained rats. CONCLUSIONS: The protective effect of previous training in CP-treated rats was associated with reduced endothelial cell lesions and increased renal production of NO in trained rats.

Effect of Physical Exercise on the Febrigenic Signaling is Modulated by Preoptic Hydrogen Sulfide Production.

We tested the hypothesis that the neuromodulator hydrogen sulfide (H2S) in the preoptic area (POA) of the hypothalamus modulates the febrigenic signaling differently in sedentary and trained rats. Besides H2S production rate and protein expressions of H2S-related synthases cystathionine ß-synthase (CBS), 3-mercaptopyruvate sulfurtransferase (3-MPST) and cystathionine γ-lyase (CSE) in the POA, we also measured deep body temperature (Tb), circulating plasma levels of cytokines and corticosterone in an animal model of systemic inflammation. Rats run on a treadmill before receiving an intraperitoneal injection of lipopolysaccharide (LPS, 100 µg/kg) or saline. The magnitude of changes of Tb during the LPS-induced fever was found to be similar between sedentary and trained rats. In sedentary rats, H2S production was not affected by LPS. Conversely, in trained rats LPS caused a sharp increase in H2S production rate that was accompanied by an increased CBS expression profile, whereas 3-MPST and CSE expressions were kept relatively constant. Sedentary rats showed a significant LPS-induced release of cytokines (IL-1ß, IL-6, and TNF-α) which was virtually abolished in the trained animals. Correlation between POA H2S and IL-6 as well as TNF-α was observed. Corticosterone levels were augmented after LPS injection in both groups. We found correlations between H2S and corticosterone, and corticosterone and IL-1ß. These data are consistent with the notion that the responses to systemic inflammation are tightly regulated through adjustments in POA H2S production which may play an anti-inflammatory role downmodulating plasma cytokines levels and upregulating corticosterone release.

Involvement of endogenous central hydrogen sulfide (H2S) in hypoxia-induced hypothermia in spontaneously hypertensive rats.

Spontaneously hypertensive rats (SHR) display autonomic imbalance and abnormal body temperature (Tb) adjustments. Hydrogen sulfide (H2S) modulates hypoxia-induced hypothermia, but its role in SHR thermoregulation is unknown. We tested the hypothesis that SHR display peculiar thermoregulatory response to hypoxia and that endogenous H2S overproduced in the caudal nucleus of the solitary tract (NTS) of SHR modulates this response. SHR and Wistar rats were microinjected into the fourth ventricle with aminooxyacetate (AOA, H2S-synthezing enzyme inhibitor) or sodium sulfide (Na2S, H2S donor) and exposed to normoxia (21% inspired O2) or hypoxia (10% inspired O2, 30 min). Tb was continuously measured, and H2S production rate was assessed in caudal NTS homogenates. In both groups, AOA, Na2S, or saline (i.e., control; 1 µL) did not affect euthermia. Hypoxia caused similar decreases in Tb in both groups. AOA presented a longer latency to potentiate hypoxic hypothermia in SHR. Caudal NTS H2S production rate was higher in SHR. We suggest that increased bioavailability of H2S in the caudal NTS of SHR enables the adequate modulation of excitability of peripheral chemoreceptor-activated NTS neurons that ultimately induce suppression of brown adipose tissue thermogenesis, thus accounting for the normal hypoxic hypothermia.

Effects of previous physical training on adriamycin nephropathy and its relationship with endothelial lesions and angiogenesis in the renal cortex.

AIMS: Adriamycin (ADR)-induced nephropathy is one of the most experimental models used in progressive kidney disease. A single dose of this drug induces a progressive and irreversible proteinuria that progresses to focal segmental glomerulosclerosis and tubulointerstitial lesions. Regular physical activity has been considered as a therapeutic intervention in several diseases. This study evaluated the influence of previous physical training in renal damage induced by ADR and the role of endothelial lesions and angiogenesis in this process. MAIN METHODS: Male Wistar rats were subjected or not to treadmill running for 4weeks and then injected with ADR (2.5mg/kg, i.v.) or saline. Twenty-four-hour urine samples were collected for albuminuria measurement, and blood samples were collected to measure plasma creatinine 60days after the injections. The kidneys were removed for histological, immunohistochemical, Western blot and ELISA studies. KEY FINDINGS: ADR-treated rats presented increases in plasma creatinine levels, albuminuria, podocyte damage, and enlargement of the tubular interstitial relative area, as well as higher macrophage numbers in the renal cortex, interleukin (IL)-1ß levels in renal tissue and urinary monocyte chemoattractant protein (MCP)-1, which were associated with reduction in vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS) expressions and peritubular capillary (PTC) density in renal cortex. These alterations were less intense in the animals subjected to previous exercise training. SIGNIFICANCE: Physical training prior to ADR injection reduced the renal damage induced by this drug. This effect was related to angiogenesis and reduction in the endothelial lesions and inflammatory process in the renal cortex of these animals.

Cryogenic role of central endogenous hydrogen sulfide in the rat model of endotoxic shock.

Thermoregulatory responses to lipopolysaccharide (LPS) are affected by modulators that increase (propyretic) or decrease (cryogenic) body temperature (Tb). We tested the hypothesis that central hydrogen sulfide (H2S) acts as a thermoregulatory modulator and that H2S production in the anteroventral preoptic region of the hypothalamus (AVPO) is increased during hypothermia and decreased during fever induced by bacterial lipopolysaccharide (LPS, 2.5mg/kg i.p.) in rats kept at an ambient temperature of 25°C. Deep Tb was recorded before and after pharmacological inhibition of the enzyme cystathionine ß-synthase (CBS - responsible for H2S endogenous production in the brain) combined or not with LPS administration. To further investigate the mechanisms responsible for these thermoregulatory adjustments, we also measured prostaglandin D2 (PGD2) production in the AVPO. LPS caused typical hypothermia followed by fever. Levels of AVPO H2S were significantly increased during hypothermia when compared to both euthermic and febrile rats. Intracerebroventricular (icv) microinjection of aminooxyacetate (AOA, a CBS inhibitor; 100 pmol) neither affected Tb nor basal PGD2 production during euthermia. In LPS-treated rats, AOA caused increased Tb values during hypothermia, along with enhanced PGD2 production. We conclude that the gaseous messenger H2S modulates hypothermia during endotoxic shock, acting as a cryogenic molecule.

Cecropia pachystachya extract attenuated the renal lesion in 5/6 nephrectomized rats by reducing inflammation and renal arginase activity.

ETHNOPHARMACOLOGICAL RELEVANCE: The plant Cecropia pachystachya Trécul has been used in Brazilian folk medicine to treat hypertension, bladder and kidney inflammation and renal diseases. The aim of this study was to evaluate the potential of the aqueous fraction from the ethanolic extract of Cecropia pachystachya (FCP) in the management of hypertension, inflammation and progressive renal disease in rats submitted to 5/6 nephrectomy. MATERIALS AND METHODS: Thirty male Wistar rats submitted to 5/6 nephrectomy (5/6 NE) were untreated (NE) or treated (NE+FCP) with the FCP (0.5g/kg/day). The treatment started 15 days after surgery, and the rats were followed for a period of 60 days. Systolic blood pressure (SBP) and albuminuria were evaluated from 15-60 days after the surgical procedure. Function and estructural renal changes, TGF-ß (transforming growth factor ß), MCP-1 (monocyte chemoattractant protein-1) and nitric oxide (NO) urinary excretion were analyzed. Expression and activity of the renal enzymes arginase (ARG), angiotensin converting enzyme (ACE), and MAP kinase p-JNK expression also were analyzed. RESULTS: The nephrectomized rats developed progressive albuminuria and increased SBP that was less intense in the treated group. There was a reduction in the glomerular filtration rate (GFR) in the nephrectomized rats, which was attenuated by treatment with FCP extract. The treatment with FCP also attenuated the histological changes, reduced the expression and activity of renal arginase, the number of macrophages (ED-1 positive cells) and the p-JNK expression in the renal cortex of the rats submitted to 5/6 NE. The urinary excretion of TGF-ß was less intense in the treated group and was associated with the reduction of the expression and activity of the renal arginase. CONCLUSIONS: These results suggest that the reduction of renal arginase activity, p-JNK and TGF-ß expression can explain the mechanism by which the treatment with C. pachystachya reduced the inflammation and improved renal function. This study presents the potential use of Cecropia pachystachya in the treatment of chronic renal diseases.

Brazilian embauba (Cecropia pachystachya) extract reduces renal lesions in 5/6 nephrectomized rats.

INTRODUCTION: Cecropia pachystachya (CP) is a plant rich in polyphenols which inhibits the angiotensin-converting enzyme (ACE) in vitro. Angiotensin II (AII) has an important role in the renal lesion provoked by 5/6 nephrectomy (NE). This study evaluated the CP extract effect on renal lesions provoked by 5/6 NE. MATERIALS AND METHODS: Male Wistar rats submitted to 5/6 NE were treated or not treated with CP extract and followed for 90 days. Systemic blood pressure (SBP), albuminuria, renal functional and structural parameters, ACE activity, urinary levels of monocyte chemoattrant protein-1 (MCP-1) and transforming growth factor ß (TGF-ß) were evaluated. RESULTS: Albuminuria and hypertension were less intense in the treated (NE+CP) group compared to the untreated (NE) group. CP extract treatment reduced the fall in glomerular filtration rate observed in NE rats. Glomerulosclerosis, tubulointerstitial lesions, increase of macrophages and AII positive cells in the renal cortex, as well as increases in renal ACE activity, urinary levels of MCP-1 and TGF-ß were attenuated in NE rats by CP treatment. CONCLUSIONS: The treatment with CP extract reduced the SBP and functional and structural renal changes in 5/6 NE rats. These effects were associated with decreased AII expression, ACE activity and inflammation in the renal cortex.

Hydrogen sulfide inhibits preoptic prostaglandin E2 production during endotoxemia.

Hydrogen sulfide (H(2)S) is a gaseous neuromodulator endogenously produced in the brain by the enzyme cystathionine ß-synthase (CBS). We tested the hypothesis that H(2)S acts within the anteroventral preoptic region of the hypothalamus (AVPO) modulating the production of prostaglandin (PG) E(2) (the proximal mediator of fever) and cyclic AMP (cAMP). To this end, we recorded deep body temperature (Tb) of rats before and after pharmacological modulation of the CBS-H(2)S system combined or not with lipopolysaccharide (LPS) exposure, and measured the levels of H(2)S, cAMP, and PGE(2) in the AVPO during systemic inflammation. Intracerebroventricular (icv) microinjection of aminooxyacetate (AOA, a CBS inhibitor; 100 pmol) did not affect basal PGE(2) production and Tb, but enhanced LPS-induced PGE(2) production and fever, indicating that endogenous H(2)S plays an antipyretic role. In agreement, icv microinjection of a H(2)S donor (Na(2)S; 260 nmol) reduced the LPS-induced PGE(2) production and fever. Interestingly, we observed that the AVPO levels of H(2)S were decreased following the immunoinflammatory challenge. Furthermore, fever was associated with decreased levels of AVPO cAMP and increased levels of AVPO PGE(2). The LPS-induced decreased levels of cAMP were reduced to a lesser extent by the H(2)S donor. The LPS-induced PGE(2) production was potentiated by AOA (the CBS inhibitor) and inhibited by the H(2)S donor. Our data are consistent with the notion that the gaseous messenger H(2)S synthesis is downregulated during endotoxemia favoring PGE(2) synthesis and lowering cAMP levels in the preoptic hypothalamus.

Fish oil supplementation reduces cachexia and tumor growth while improving renal function in tumor-bearing rats.

The objective of the present work was to study the renal function of healthy and tumor-bearing rats chronically supplemented with fish oil (FO), a source of n-3 polyunsaturated fatty acids. Weanling male rats were divided in two groups, one control (C) and another orally supplemented for 70 days with FO (1 g/kg body weight). After this time, half the animals of each group were injected in the right flank with a suspension of Walker 256 tumor cells (W and WFO). The W group had less proteinemia reflecting cachectic proteolysis, FO reversed this fact. Tumor weight gain was also reduced in WFO. Glomerular filtration rate (GFR) was not different in FO or W compared to C, but was higher in WFO. Renal plasma flow (RPF) was higher in the FO supplemented groups. The W group had lower plasma osmolality than the C group, but FO supplementation resulted in normalization of this parameter. Fractional sodium excretion (FE(Na+)) of FO rats was similar to C. Proximal Na(+) reabsorption, evaluated by lithium clearance, was similar among the groups. Urinary thromboxane B(2) (TXB(2)) excretion was lower in the supplemented groups. The number of macrophages in renal tissue was higher in W compared to C rats, but was lower in WFO rats compared to W rats. In conclusion, FO supplementation resulted in less tumor growth and cachexia, and appeared to be renoprotective, as suggested by higher RPF and GFR.

Previous exposure to cigarette smoke aggravates experimental cyclosporine-induced nephrotoxicity.

BACKGROUND/AIMS: The effects of cigarette smoke (CS) on cyclosporine (CsA)-induced nephrotoxicity are poorly studied. This study aims to assess the effects of previous exposure to CS on CsA nephrotoxicity. METHODS: Rats were either exposed to CS or sham (S) procedures for 10 min twice a day for 20 weeks. From the 16th to the 20th week, they received a low-salt diet. Beginning with the 17th week, they were given 2.5 mg/day CsA or vehicle (VH) for 3 weeks. The final groups were VH/CS, CsA/CS, VH/S, and CsA/S. On day 141, glomerular filtration rate (GFR), renal blood flow (RBF), renal vascular resistance (RVR), tubulointerstitial fibrosis, and CsA blood levels were measured and immunohistochemistry was analyzed for renal α-smooth muscle actin (SMA), nitrotyrosine, and vimentin. RESULTS: CsA decrease in GFR was enhanced by CS exposure. CsA associated with CS induced higher periglomerular α-SMA and renal nitrotyrosine expression. CsA decreased RBF, but increased RVR, tubulointerstitial fibrosis, and α-SMA and renal vimentin expression. These changes and the CsA blood levels were not affected by CS exposure. CONCLUSION: CS aggravated the CsA-induced impairment of GFR and CS associated with CsA caused the development of periglomerular structural lesions and oxidative stress in a rat model of CsA nephrotoxicity.

Renal Development and Blood Pressure in Offspring from Dams Submitted to High-Sodium Intake during Pregnancy and Lactation.

Exposure to an adverse environment in utero appears to programme physiology and metabolism permanently, with long-term consequences for health of the fetus or offspring. It was observed that the offspring from dams submitted to high-sodium intake during pregnancy present disturbances in renal development and in blood pressure. These alterations were associated with lower plasma levels of angiotensin II (AII) and changes in renal AII receptor I (AT(1)) and mitogen-activated protein kinase (MAPK) expressions during post natal kidney development. Clinical and experimental evidence show that the renin-angiotensin system (RAS) participates in renal development. Many effects of AII are mediated through MAPK pathways. Extracellular signal-regulated protein kinases (ERKs) play a pivotal role in cellular proliferation and differentiation. In conclusion, high-sodium intake during pregnancy and lactation can provoke disturbances in renal development in offspring leading to functional and structural alterations that persist in adult life. These changes can be related at least in part with the decrease in RAS activity considering that this system has an important role in renal development.

Alpha-tocopherol prevents intrauterine undernutrition-induced oligonephronia in rats.

The role of α-tocopherol during nephrogenesis was investigated in rats subjected to maternal undernutrition, which reduces the number of nephrons. α-tocopherol (350 mg/kg, p.o.) was administered daily to well-nourished or malnourished Wistar dams during pregnancy, or to prenatal undernourished rats during lactation. The kidneys of 1- and 25-day-old offspring were removed to evaluate expression of angiotensin II (Ang II) and to correlate this with expression of proliferating cell nuclear antigen, α-smooth muscle actin, fibronectin and vimentin in the glomeruli and tubulointerstitial space. One-day-old prenatally undernourished rats had reduced expression of Ang II and of kidney development markers, and presented with an enlarged nephrogenic zone. Maternal administration of α-tocopherol restored the features of normal kidney development in undernourished rats. Twenty-five-day-old prenatally undernourished progeny had fewer glomeruli than the control group. Conversely, animals from mothers that received α-tocopherol during lactation presented with the same number of glomeruli and the same glomerular morphometrical profile as the control group. Analyzing the levels of thiobarbituric acid reactive substances in the liver in conjunction with kidney development markers, it is plausible that α-tocopherol had antioxidant and non-antioxidant actions. This study provides evidence that α-tocopherol treatment restored Ang II expression, and subsequently restored renal structural development.

Effect of stem cells seeded onto biomaterial on the progression of experimental chronic kidney disease.

Different routes for the administration of bone marrow-derived cells (BMDC) have been proposed to treat the progression of chronic renal failure (CRF). We investigated whether (1) the use of bovine pericardium (BP) as a scaffold for cell therapy would retard the progression of CRF and (2) the efficacy of cell therapy differently impacts distinct degrees of CRF. We used 2/3 and 5/6 models of renal mass reduction to simulate different stages of chronicity. Treatments consisted of BP seeded with either mesenchymal or mononuclear cells implanted in the parenchyma of remnant kidney. Renal function and proteinuria were measured at days 45 and 90 after cell implantation. BMDC treatment reduced glomerulosclerosis, interstitial fibrosis and lymphocytic infiltration. Immunohistochemistry showed decreased macrophage accumulation, proliferative activity and the expression of fibronectin and α-smooth muscle-actin. Our results demonstrate: (1) biomaterial combined with BMDC did retard the progression of experimental CRF; (2) cellular therapy stabilized serum creatinine (sCr), improved creatinine clearance and 1/sCr slope when administered during the less severe stages of CRF; (3) treatment with combined therapy decreased glomerulosclerosis, fibrosis and the expression of fibrogenic molecules; and (4) biomaterials seeded with BMDC can be an alternative route of cellular therapy.

Macrophage depletion attenuates chronic cyclosporine A nephrotoxicity.

BACKGROUND: Cyclosporine A (CsA)-induced chronic nephrotoxicity is characterized by renal dysfunction and interstitial fibrosis. Early and progressive renal macrophage influx, correlating with latter interstitial fibrotic areas, has been associated with CsA treatment. This study investigated the role of macrophages, the nitric oxide (NO) pathway, and the oxidative stress on chronic CsA nephrotoxicity. METHODS: The macrophages were depleted by clodronate liposomes. Animals were distributed into four groups: vehicle (olive oil for 21 days), CsA 7.5 mg/kg per day (21 days), CsA plus clodronate (5 mg/mL intraperitoneally on days -4, 1, 4, 11, and 18 of CsA treatment), or vehicle plus clodronate. On day 22, glomerular filtration rate, renal blood flow, renal tubulointerstitial fibrosis, CsA blood levels, serum malondialdehyde and renal tissue immunohistochemistry for macrophages, inducible NO synthase, transforming growth factor-beta, nuclear factor-kbeta, alpha-smooth muscle actin, vimentin, and nitrotyrosine were assessed. RESULTS: CsA-induced increase in the macrophage was prevented by clodronate. Macrophage depletion attenuated the reductions in the glomerular filtration rate and renal blood flow, the development of tubulointerstitial fibrosis, malondialdehyde increase and increases in nuclear factor-kbeta, transforming growth factor-beta, vimentin, inducible NO synthase, and nitrotyrosine expression provoked by CsA. Clodronate did not affect alpha-smooth muscle actin expression and CsA blood levels. CONCLUSIONS: Renal macrophage influx plays an important role in CsA-induced chronic nephrotoxicity. The NO pathway and oxidative stress are likely mechanisms involved in the genesis of this form of renal injury.

Ontogenetic role of angiontensin-converting enzyme in rats: thirst and sodium appetite evaluation.

We investigated the influence of captopril (an angiotensin converting enzyme inhibitor) treatment during pregnancy and lactation period on hydromineral balance of the male adult offspring, particularly, concerning thirst and sodium appetite. We did not observe significant alterations in basal hydromineral (water intake, 0.3M NaCl intake, volume and sodium urinary concentration) or cardiovascular parameters in adult male rats perinatally treated with captopril compared to controls. However, male offspring rats that perinatally exposed to captopril showed a significant attenuation in water intake induced by osmotic stimulation, extracellular dehydration and beta-adrenergic stimulation. Moreover, captopril treatment during perinatal period decreased the salt appetite induced by sodium depletion. This treatment also attenuated thirst and sodium appetite aroused during inhibition of peripheral angiotensin II generation raised by low concentration of captopril in the adult offspring. Interestingly, perinatal exposure to captopril did not alter water or salt intake induced by i.c.v. administration of angiotensin I or angiotensin II. These results showed that chronic inhibition of angiotensin converting enzyme during pregnancy and lactation modifies the regulation of induced thirst and sodium appetite in adulthood.