RESUMEN
Little is known about the effect of the recently developed calcimimetic evocalcet (Evo) on parathyroid calcium-sensing receptor (CaSR) and vitamin D receptor (VDR) expression. We examined the effects of Evo and cinacalcet (Cina) on CaSR and VDR expression in 5/6 nephrectomized Sprague-Dawley rats fed a high-phosphorus diet for 4 weeks to develop secondary hyperparathyroidism (SHPT). These uremic rats were divided into 4 groups-baseline control (Nx4W) and groups with additional treatment with either the Vehicle, Evo, or Cina for 2 weeks; normal rats were used as normal controls (NC). Blood parameters and parathyroid tissue were analyzed. CaSR and VDR expression levels were determined using immunohistochemistry. The degree of kidney injury and hyperphosphatemia was similar in the uremic groups (Nx4W, Vehicle, Cina, and Evo). Serum parathyroid hormone levels were significantly higher in the Nx4W and Vehicle groups than in the NC group. This increase was significantly suppressed in the Cina and Evo groups compared with that in the Vehicle group. Serum calcium levels were significantly and equally lower in the Cina and Evo groups relative to those in the Vehicle group. CaSR expression was significantly lower in the Nx4W and Vehicle groups than in the NC group. This downregulation was of an equally lesser magnitude in the Cina and Evo groups. A similar trend was observed for VDR expression. These results indicate that Evo and Cina treatment can increase parathyroid CaSR and VDR expression in uremic rats with SHPT, which could provide better control of mineral and bone disorder markers.
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Hiperparatiroidismo Secundario , Receptores de Calcitriol , Ratas , Animales , Receptores de Calcitriol/metabolismo , Receptores Sensibles al Calcio/metabolismo , Ratas Sprague-Dawley , Glándulas Paratiroides/metabolismo , Hiperparatiroidismo Secundario/tratamiento farmacológico , Hiperparatiroidismo Secundario/complicaciones , Hiperparatiroidismo Secundario/metabolismo , Hormona Paratiroidea/metabolismo , Cinacalcet/farmacología , Cinacalcet/metabolismoRESUMEN
OBJECTIVES: To define groups and characterize differences in the prognosis of patients with adult-onset Still's disease (AOSD). METHODS: We performed a retrospective cohort study. Patients with AOSD were grouped using hierarchical unsupervised cluster analysis according to age, sex, clinical features, and laboratory data. The primary endpoints were overall survival and drug-free remission rate. RESULTS: A total of 153 patients with AOSD were placed into four clusters. Those in Cluster 1 had a young onset, tended to be female, and had fewer complications and moderate ferritin concentrations. Those in Cluster 2 had a young onset and had more complications and higher ferritin concentrations. Those in Cluster 3 had a young onset, tended to be male, and had no lymphadenopathy and fewer complications. Those in Cluster 4 had an older onset, tended to be female, and had more complications and higher ferritin concentrations. Overall survival tended to be lower (P = .0539) in Cluster 4, and drug-free remission was higher in Clusters 1, 2, and 3 [hazard ratios (HRs) 2.19, 3.37, and 3.62 vs. Cluster 4, respectively]. CONCLUSIONS: Four groups of AOSD that have distinct clinical manifestations, ferritin concentrations, severity, and drug-free remission rate were identified, which were lowest in Cluster 4. Graphical Abstract.
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OBJECTIVES: To investigate the usefulness of severity classification for predicting outcomes in patients with adult-onset Still's disease (AOSD). METHODS: This was a multi-centre retrospective cohort study. AOSD patients were classified into mild, moderate, and severe groups based on severity classification (Japanese Ministry of Health, Labour and Welfare) during the initial treatment, and clinical features were compared among these groups. The primary endpoints were the AOSD-related mortality and drug-free remission rate. For comparison, the same analysis was performed in parallel for patient groups stratified by the modified Pouchot systemic score. RESULTS: According to severity classification, 49 (35%), 37 (26%), and 56 patients (39%) were classified into mild, moderate, and severe groups, respectively. Patients in the severe group showed higher frequency of severe complications and the use of biological agents. Although AOSD-related survival was not significantly different (p = .0776), four of the five fatal cases were classified into the severe group. The severe group showed a reduced rate of drug-free remission (p = .0125). Patient groups classified by systemic score did not correlate with survival or drug-free remission. CONCLUSIONS: Severity classification is useful for predicting outcomes in patients with AOSD.
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Enfermedad de Still del Adulto , Adulto , Humanos , Japón , Estudios Retrospectivos , Enfermedad de Still del Adulto/diagnóstico , Enfermedad de Still del Adulto/tratamiento farmacológicoRESUMEN
OBJECTIVE: Based on the antibody profiles of inflammatory myositis patients, we investigated the type 1 IFN (T1-IFN) signature in serum and DM skin to determine the relationship between T1-IFN and vasculopathy in anti-melanoma differentiation-associated 5 gene (MDA5) antibody-positive DM patients. METHODS: We examined 47 patients with new-onset inflammatory myositis. We divided them into three groups: the anti-MDA5 antibody-positive patients (MDA5 group, n = 16), the anti-aminoacyl-tRNA synthetase antibody-positive patients (aminoacyl-tRNA synthetase group, n = 12), and the double-negative patients (n = 19). Serum T1-IFN signatures were revealed by a functional reporter assay, and we evaluated the T1-IFN signatures of skin based on Mx1 expression by immunohistochemistry. RESULTS: The numbers of patients with classical DM, clinically amyopathic DM and interstitial lung disease were 1, 15 and 13 in the MDA5 group, 2, 3 and 11 in the aminoacyl-tRNA synthetase group, and 10, 1 and 4 in the double-negative group, respectively. The signs of vasculopathies (i.e. palmer papules, skin ulcers and mononeuritis multiplex) were identified only in the MDA5 patients. Most of the MDA5 group showed the highest serum T1-IFN signatures among the three groups. In the histological analysis of DM skin, perivascular inflammations were significant in the MDA5 group. The MDA5 group's Mx1 expression was significantly strong, distributed in blood vessels and interstitial fibroblasts, and had spread to deep dermis. CONCLUSION: Anti-MDA5 antibody-positive DM patients showed high T1-IFN signatures in serum and affected skin. The high T1-IFN signatures of the MDA5 antibody-positive DM patients in serum and deep vasculatures suggested that T1-IFN may have important roles in the vasculopathy of these patients.
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Autoanticuerpos/inmunología , Dermatomiositis/inmunología , Interferón Tipo I/inmunología , Helicasa Inducida por Interferón IFIH1/inmunología , Enfermedades Vasculares/inmunología , Aminoacil-ARNt Sintetasas/inmunología , Autoanticuerpos/sangre , Estudios de Cohortes , Dermatomiositis/sangre , Femenino , Humanos , Enfermedades Pulmonares Intersticiales/inmunología , Masculino , Persona de Mediana Edad , Miositis/inmunologíaRESUMEN
The objectives of this study are to determine whether the 2016 European League Against Rheumatism/American College of Rheumatology/Paediatric Rheumatology International Trials Organization classification criteria for macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (SJIA) can be used to identify MAS in patients with adult-onset Still's disease (AOSD). Using laboratory data from 76 AOSD patients with and without MAS, we analyzed the ability of the collective and individual constitutive elements of the 2016 MAS in SJIA criteria and additional laboratory measures to discriminate between AOSD patients with (n = 16) and without (n = 60) MAS. Cutoff values to determine the sensitivity, specificity, and predictive values were calculated from receiver operating characteristic curves, and modified classification criteria for MAS in AOSD were evaluated. The 2016 MAS in SJIA classification criteria had an overall sensitivity of 100%, specificity of 70.0%, positive predictive value of 47.1%, and negative predictive value of 100% to discriminate between AOSD patients with and without MAS based on laboratory data. Among the individual criteria, the sensitivity of triglycerides (46.7%) and the specificity of ferritin (15.0%) for MAS in AOSD were particularly low. The sensitivity and specificity for classifying MAS in AOSD patients were increased to 100 and 93%, respectively, by excluding triglycerides and changing the cutoff values for other criteria in the 2016 MAS in SJIA classification. The 2016 classification criteria for MAS in SJIA had higher sensitivity but lower specificity to identify MAS in AOSD patients compared with SJIA patients.
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Artritis Juvenil/complicaciones , Síndrome de Activación Macrofágica/clasificación , Enfermedad de Still del Adulto/complicaciones , Adulto , Femenino , Humanos , Síndrome de Activación Macrofágica/complicaciones , Síndrome de Activación Macrofágica/diagnóstico , Masculino , Estudios Retrospectivos , Reumatología , Sensibilidad y EspecificidadRESUMEN
Saxagliptin, a potent and selective DPP-4 inhibitor, exhibits a slow dissociation from DPP-4. We investigated the sustained effects of saxagliptin on renal DPP-4 activity in a washout study using renal tubular (HK-2) cells, and in a pharmacodynamic study using normal rats. In HK-2 cells, the inhibitory potency of saxagliptin on DPP-4 activity persisted after washout, while that of sitagliptin was clearly reduced. In normal rats, a single treatment of saxagliptin or sitagliptin inhibited the plasma DPP-4 activity to similar levels. The inhibitory action of saxagliptin on the renal DPP-4 activity was retained, even when its inhibitory effect on the plasma DPP-4 activity disappeared. However, the inhibitory action of sitagliptin on the renal DPP-4 activity was abolished in correlation with the inhibition of the plasma DPP-4 activity. In situ staining showed that saxagliptin suppressed the DPP-4 activity in both glomerular and tubular cells and its inhibitory effects were significantly higher than those of sitagliptin. Saxagliptin exerted a sustained inhibitory effect on the renal DPP-4 activity in vitro and in vivo. The long binding action of saxagliptin in renal tubular cells might involve the sustained inhibition of renal DPP-4.
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Adamantano/análogos & derivados , Dipéptidos/farmacología , Dipeptidil Peptidasa 4/metabolismo , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Glomérulos Renales/enzimología , Túbulos Renales/enzimología , Adamantano/metabolismo , Adamantano/farmacología , Animales , Células Cultivadas , Dipéptidos/metabolismo , Dipeptidil Peptidasa 4/sangre , Inhibidores de la Dipeptidil-Peptidasa IV/metabolismo , Humanos , Masculino , Unión Proteica , Ratas Sprague-Dawley , Fosfato de Sitagliptina/farmacologíaRESUMEN
BACKGROUND: Patients with Alzheimer's disease (AD) manifest various impairments in eating behavior. However, few previous studies have directly investigated the gustatory function of AD patients, and results have been inconsistent. METHODS: Thirty-two AD patients (Clinical Dementia Rating (CDR) 0.5/1/2, respectively 11/15/6 patients) and 22 normal control participants were examined to measure detection and recognition thresholds of the four elemental tastes (sweet, salty, sour, and bitter), and their ability to discriminate between tastes. Effects of demographic and clinical factors (age, sex, histories of alcohol and tobacco consumption, and CDR grade) on gustatory threshold were examined using ordinal logistic regression analysis. Performance was compared between AD and control groups. RESULTS: Total threshold values (the sum of threshold grades for the four tastes) for detection and recognition of tastes were significantly higher in the AD group. Detection thresholds for sweet, salty, and bitter, and recognition thresholds for sweet and sour, were also significantly higher in the AD group. Ordinal logistic regression analysis revealed that CDR grade was the only factor that significantly affected both total threshold values. Regarding taste discrimination, there were no significant differences between the AD group and control group. CONCLUSIONS: These findings suggest that progression of dementia severity accompanies gustatory decline. Although it seemingly paradoxical, weight loss and preference for sweet tastes are frequently, often simultaneously, observed in AD. Gustatory dysfunction may be partially involved in these symptoms. Thus, the nutritional care of patients with AD could be improved by making the taste of meals stronger, while controlling calorie and mineral intake.
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Enfermedad de Alzheimer/fisiopatología , Disgeusia/etiología , Umbral Gustativo , Gusto/fisiología , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Progresión de la Enfermedad , Disgeusia/diagnóstico , Humanos , Imagen por Resonancia Magnética , MasculinoAsunto(s)
Anticuerpos Monoclonales Humanizados/farmacocinética , Antirreumáticos/farmacocinética , Artritis Reumatoide/tratamiento farmacológico , Intercambio Materno-Fetal , Complicaciones del Embarazo/tratamiento farmacológico , Adulto , Femenino , Humanos , Recién Nacido , Embarazo , Resultado del Embarazo , Efectos Tardíos de la Exposición PrenatalRESUMEN
To elucidate the effect of evocalcet, a new oral calcimimetic to bone of secondary hyperparathyroidism (SHPT) with chronic kidney disease (CKD), the rats were 5/6 nephrectomized and fed on a high-phosphate diet. The treated rats were then divided into vehicle groups and evocalcet administered groups. The rats in the vehicle groups exhibited increased levels of serum PTH and inorganic phosphate (Pi) levels, high bone turnover, and severe cortical porosity, mimicking SHPT (CKD-SHPT rats). The cortical bone of the CKD-SHPT rats showed broad demineralization around the osteocytes, suppression of Phex/small integrin-binding ligand N-linked glycoprotein-mediated mineralization in the periphery of the osteocytic lacunae, and increased levels of osteocytic cell death, all of which were considered as the first steps of cortical porosity. In contrast, evocalcet ameliorated the increased serum PTH levels, the enlarged osteocytic lacunae, and the cortical porosity of the CKD-SHPT rats. Osteocytes of CKD-SHPT rats strongly expressed PTH receptor and Pit1/Pit2, which sense extracellular Pi, indicating that PTH and Pi affected these osteocytes. Cell death of cultured osteocytes increased in a Pi concentration-dependent manner, and PTH administration rapidly elevated Pit1 expression and enhanced osteocytic death, indicating the possibility that the highly concentrated serum PTH and Pi cause severe perilacunar osteolysis and osteocytic cell death. It is likely therefore that evocalcet not only decreases serum PTH but also reduces the exacerbation combined with PTH and Pi to the demineralization of osteocytic lacunae and osteocytic cell death, thereby protecting cortical porosity in CKD-SHPT rats.
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Hiperparatiroidismo Secundario , Insuficiencia Renal Crónica , Ratas , Masculino , Animales , Porosidad , Hiperparatiroidismo Secundario/etiología , Naftalenos , Insuficiencia Renal Crónica/complicaciones , Hormona ParatiroideaRESUMEN
A 74-year-old woman was admitted to Gunma University Hospital because of dysphagia symptoms. A gastrointestinal contrast study demonstrated a large esophageal hiatal sliding hernia affecting the passage of barium at the lower end of the esophagus. Manometric studies showed hypotensive pressure in the lower esophageal sphincter (LES) and relaxation failure of the LES during swallowing. We diagnosed a combination of sliding hiatal hernia with nonspecific esophageal motility disorder (NEMD). Thoracoscopically assisted Heller myotomy and Dor fundoplication by abdominal open surgery were then performed. The patient is currently well and is free from dysphagia symptoms. Treatment with combination thoracoscopic and abdominal open surgery was effective. We report here the first case of combined hiatal hernia with NEMD treated by thoracoscopic and abdominal open surgery.
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Trastornos de la Motilidad Esofágica/cirugía , Hernia Hiatal/cirugía , Anciano , Trastornos de la Motilidad Esofágica/complicaciones , Trastornos de la Motilidad Esofágica/diagnóstico , Femenino , Fundoplicación/métodos , Hernia Hiatal/complicaciones , Hernia Hiatal/diagnóstico , Humanos , ToracoscopíaRESUMEN
BACKGROUND: Elevated parathyroid hormone (PTH) levels in secondary hyperparathyroidism (SHPT) lead to vascular calcification, which is associated with cardiovascular events and mortality. Increased PTH production is caused by the excessive proliferation of parathyroid gland cells, which is accelerated by abnormal mineral homeostasis. Evocalcet, an oral calcimimetic agent, inhibits the secretion of PTH from parathyroid gland cells and has been used for the management of SHPT in dialysis patients. We observed the effects of evocalcet on ectopic calcification and parathyroid hyperplasia using chronic kidney disease (CKD) rats with SHPT. METHODS: CKD rats with SHPT induced by adenine received evocalcet orally for 5 weeks. The calcium and inorganic phosphorus content in the aorta, heart and kidney was measured. Ectopic calcified tissues were also assessed histologically. To observe the effects on the proliferation of parathyroid gland cells, parathyroid glands were histologically assessed in CKD rats with SHPT induced by 5/6 nephrectomy (Nx) after receiving evocalcet orally for 4 weeks. RESULTS: Evocalcet prevented the increase in calcium and inorganic phosphorus content in the ectopic tissues and suppressed calcification of the aorta, heart and kidney in CKD rats with SHPT by reducing the serum PTH and calcium levels. Evocalcet suppressed the parathyroid gland cell proliferation and reduced the sizes of parathyroid cells in CKD rats with SHPT. CONCLUSIONS: These findings suggest that evocalcet would prevent ectopic calcification and suppress parathyroid hyperplasia in patients with SHPT.
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Hiperparatiroidismo Secundario/complicaciones , Naftalenos/uso terapéutico , Glándulas Paratiroides/patología , Pirrolidinas/uso terapéutico , Calcificación Vascular/prevención & control , Animales , Calcimiméticos/uso terapéutico , Hiperplasia/etiología , Hiperplasia/prevención & control , Masculino , Ratas , Ratas Sprague-Dawley , Calcificación Vascular/etiologíaRESUMEN
The authors previously demonstrated that isoflurane, a widely used volatile anesthetic, induced depolarization and increased the frequency of spontaneous action potentials in principal dopamine neurons in rat substantia nigra pars compacta. We studied the effects of isoflurane on voltage-dependent K channels to clarify the mechanisms of the increase in excitability in these neurons. Voltage-clamp whole-cell recordings were made in rat midbrain slices. We recorded the outward membrane currents in response to depolarizing voltage steps from -120 mV and -25 mV and isolated the transient outward current mediated through A-type K channels by subtraction. Isoflurane at clinically relevant concentrations accelerated the decay of the A-type K current and delayed the recovery from inactivation without changing the steady-state inactivation curves. Isoflurane did not affect the non-inactivating outward current. Addition of 4-aminopyridine partially occluded the excitatory effects of isoflurane in current-clamp recordings. These results demonstrate that isoflurane accelerated the inactivation and delayed the recovery from inactivation of A-type K channels in principal neurons in rat substantia nigra pars compacta without affecting delayed rectifier K channels. These effects may contribute in part to excitation of these neurons and the isoflurane-induced increases in dopamine release reported in vitro and in vivo.
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Anestésicos por Inhalación/farmacología , Canales de Potasio de Tipo Rectificador Tardío/efectos de los fármacos , Isoflurano/farmacología , Canales de Potasio Shal/efectos de los fármacos , 4-Aminopiridina/farmacología , Anestésicos por Inhalación/administración & dosificación , Animales , Canales de Potasio de Tipo Rectificador Tardío/metabolismo , Dopamina/metabolismo , Electrofisiología , Isoflurano/administración & dosificación , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Técnicas de Placa-Clamp , Ratas , Ratas Sprague-Dawley , Canales de Potasio Shal/metabolismo , Sustancia Negra/efectos de los fármacos , Sustancia Negra/metabolismoRESUMEN
In order to examine the effects of estrogen, androgen, and phytoestrogen on maternal behavior induced by exposure to fresh pups in ovariectomized nulliparous rats, 1 mg estradiol benzoate (EB), 1 mg testosterone propionate (TP), 1 mg coumestrol (CM), or oil (female control) was injected subcutaneously daily for 10 days. To elucidate the sex difference, 1 mg EB or oil (male control) was injected in orchidectomized rats by the same method as that used in nulliparous rats. Exposure to fresh pups was started 6 days after the first injection. Behavioral tests were carried out daily for 5 days from the first exposure to the last on the 10th day. In the behavioral test, the onset of retrieving and licking behaviors was recorded. In female control rats, the median onset day of retrieving behavior was day 5. Onset in the EB female group was day 1.5, which was shorter than that in the female control (P<0.05). TP female and CM female rats started to show retrieving at day 5 and day 4.5, respectively, comparable to the female controls. In males, the median day of retrieving onset in the control and EB groups was over day 5 and day 4.5, respectively. No statistical difference was seen between the female and male controls. In contrast, there was a difference between the EB-treated female and EB male groups. Licking activity was less frequent than seen in the retrieving behavior among all groups, but there was no statistical difference among the groups. These results suggest that estrogen facilitates retrieving behavior in female, but not in male rats. TP and CM have no effect on retrieving behavior in female rats.
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Conducta Animal/efectos de los fármacos , Hormonas/farmacología , Animales , Animales Recién Nacidos , Cumestrol/administración & dosificación , Cumestrol/farmacología , Estradiol/administración & dosificación , Estradiol/farmacología , Femenino , Hormonas/administración & dosificación , Inyecciones Subcutáneas , Masculino , Conducta Materna/efectos de los fármacos , Comportamiento de Nidificación/efectos de los fármacos , Orquiectomía , Ovariectomía , Paridad , Fitoestrógenos/administración & dosificación , Fitoestrógenos/farmacología , Embarazo , Ratas , Ratas Wistar , Testosterona/administración & dosificación , Testosterona/farmacologíaRESUMEN
OBJECTIVE: To investigate the gustatory function in patients with semantic dementia (SD). METHODS: Detection and recognition thresholds of the 4 basic tastes (sweet, salty, sour, and bitter), taste discrimination, and taste identification were evaluated in 18 patients with SD, 18 patients with Alzheimer disease (AD), and 22 healthy controls. RESULTS: Total detection and recognition threshold values were significantly higher in the SD and AD groups than in the control group. Patients with early-stage SD (Clinical Dementia Rating Scale score 0.5) exhibited significantly higher detection and recognition thresholds relative to controls, while increases in recognition threshold were only noted in patients with AD. Patients with SD exhibited significantly higher thresholds for the detection of sweet and salty tastes and the recognition of salty, sour, and bitter tastes, while patients with AD exhibited significantly higher thresholds only for the recognition of salty and sour tastes. Taste discrimination was preserved, whereas taste identification was disturbed, in both the SD and AD groups. CONCLUSIONS: Gustatory dysfunction at both the sensory and semantic levels may be among the early symptoms of SD. Although patients with SD had difficulty detecting sweet tastes, they more easily recognized these tastes than others, which may explain their strong preference for sweets.
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Although previous studies have shown an important role of renal dipeptidyl peptidase-4 (DPP-4) inhibition in ameliorating kidney injury in hypertensive rats, the renal distribution of DPP-4 and mechanisms of renoprotective action of DPP-4 inhibition remain unclear. In this study, we examined the effects of the DPP-4 inhibitor saxagliptin on DPP-4 activity in renal cells (using in situ DPP-4 staining) and on renal gene expression related to inflammation and fibrosis in the renal injury in hypertensive Dahl salt-sensitive (Dahl-S) rats. Male rats fed a high-salt (8% NaCl) diet received vehicle (water) or saxagliptin (12.7mg/kg/day) for 4 weeks. Blood pressure (BP), serum glucose and 24-h urinary albumin and sodium excretions were measured, and renal histopathology was performed. High salt-diet increased BP and urinary albumin excretion, consequently resulting in glomerular sclerosis and tubulointerstitial fibrosis. Although saxagliptin did not affect BP and blood glucose levels, it significantly ameliorated urinary albumin excretion. In situ staining showed DPP-4 activity in glomerular and tubular cells. Saxagliptin significantly suppressed DPP-4 activity in renal tissue extracts and in glomerular and tubular cells. Saxagliptin also significantly attenuated the increase in inflammation and fibrosis-related gene expressions in the kidney. Our results demonstrate that saxagliptin inhibited the development of renal injury independent of its glucose-lowering effect. Glomerular and tubular DPP-4 inhibition by saxagliptin was associated with improvements in albuminuria and the suppression of inflammation and fibrosis-related genes. Thus, local glomerular and tubular DPP-4 inhibition by saxagliptin may play an important role in its renoprotective effects in Dahl-S rats.
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Adamantano/análogos & derivados , Citoprotección/efectos de los fármacos , Dipéptidos/farmacología , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Hipertensión/tratamiento farmacológico , Riñón/efectos de los fármacos , Adamantano/farmacología , Adamantano/uso terapéutico , Animales , Glucemia/metabolismo , Presión Sanguínea/efectos de los fármacos , Creatinina/sangre , Dipéptidos/uso terapéutico , Dipeptidil Peptidasa 4/sangre , Dipeptidil Peptidasa 4/metabolismo , Inhibidores de la Dipeptidil-Peptidasa IV/uso terapéutico , Fibrosis , Regulación de la Expresión Génica/efectos de los fármacos , Hipertensión/metabolismo , Hipertensión/patología , Hipertensión/fisiopatología , Riñón/metabolismo , Riñón/patología , Glomérulos Renales/efectos de los fármacos , Glomérulos Renales/metabolismo , Glomérulos Renales/patología , Túbulos Renales/efectos de los fármacos , Túbulos Renales/metabolismo , Túbulos Renales/patología , Masculino , Miocardio/patología , Tamaño de los Órganos/efectos de los fármacos , Ratas , Ratas Endogámicas Dahl , Sodio/orinaRESUMEN
Saxagliptin, a potent dipeptidyl peptidase-4 (DPP-4) inhibitor, is currently used to treat type 2 diabetes mellitus, and it has been reported to exhibit a slower rate of dissociation from DPP-4 compared with another DPP-4 inhibitor, sitagliptin. In this study, we compared the effects of saxagliptin and sitagliptin on hypertension-related renal injury and the plasma and renal DPP-4 activity levels in Dahl salt-sensitive hypertensive (Dahl-S) rats. The high-salt diet (8% NaCl) significantly increased the blood pressure and quantity of urinary albumin excretion and induced renal glomerular injury in the Dahl-S rats. Treatment with saxagliptin (14mg/kg/day via drinking water) for 4 weeks significantly suppressed the increase in urinary albumin excretion and tended to ameliorate glomerular injury without altering the blood glucose levels and systolic blood pressure. On the other hand, the administration of sitagliptin (140mg/kg/day via drinking water) did not affect urinary albumin excretion and glomerular injury in the Dahl-S rats. Meanwhile, the high-salt diet increased the renal DPP-4 activity but did not affect the plasma DPP-4 activity in the Dahl-S rats. Both saxagliptin and sitagliptin suppressed the plasma DPP-4 activity by 95% or more. Although the renal DPP-4 activity was also inhibited by both drugs, the inhibitory effect of saxagliptin was more potent than that of sitagliptin. These results indicate that saxagliptin has a potent renoprotective effect in the Dahl-S rats, independent of its glucose-lowering actions. The inhibition of the renal DPP-4 activity induced by saxagliptin may contribute to ameliorating renal injury in hypertension-related renal injury.