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1.
Neuropeptides ; 105: 102418, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38442503

RESUMO

The aim of this study is to verify the impact of Leptin in blood pressure (BP) regulation and Leptin-resistance in metabolic/neurogenic hypertension through baroreflex afferents and dysregulation. Artery BP/heart rate (HR) were measured while nodose (NG) microinjection of Leptin, membrane depolarization/inward current were obtained by whole-cell patch from NG neurons isolated from adult female rats. Baroreflex sensitivity (BRS) tested with PE/SNP, distribution/expression of Leptin/receptors in the NG/nucleus tractus solitary (NTS) examined using immumostaining and qRT-PCR, and serum concentrations of Leptin/NE measured by ELISA were observed in control and high fructose-drinking induced hypertension (HTN-HFD) rats. The results showed that BP was significantly/dose-dependently reduced by Leptin NG microinjection likely through direct excitation of female-specific subpopulation of Ah-type neurons showing a potent membrane depolarization/inward currents. Sex-specific distribution/expression of OB-Ra/OB-Rb in the NG were detected with estrogen-dependent manner, similar observations were also confirmed in the NTS. As expected, BRS was dramatically decreased in the presence of PE/SNP in both male and female rats except for the female with PE at given concentrations. Additionally, serum concentration of Leptin was elevated in HFD-HTN model rats of either sex with more obvious in females. Under hypertensive condition, the mean fluorescent density of OB-R and mRNA expression for OB-Ra/OB-Rb in the NG/NTS were significantly down-regulated. These results have demonstrated that Leptin play a role in dominant parasympathetic drive via baroreflex afferent activation to buffer Leptin-mediated sympathetic activation systemically and Leptin-resistance is an innegligible mechanism for metabolic/neurogenic hypertension through baroreflex afferent dysregulation.


Assuntos
Barorreflexo , Pressão Sanguínea , Hipertensão , Leptina , Animais , Feminino , Masculino , Ratos , Barorreflexo/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Leptina/farmacologia , Leptina/metabolismo , Leptina/sangue , Neurônios/metabolismo , Neurônios/efeitos dos fármacos , Gânglio Nodoso/metabolismo , Gânglio Nodoso/efeitos dos fármacos , Ratos Sprague-Dawley , Receptores para Leptina/metabolismo , Núcleo Solitário/metabolismo , Núcleo Solitário/efeitos dos fármacos
2.
Chemosphere ; 302: 134742, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35525451

RESUMO

Wastewater from rare earth mining (WREM) is very harmful to environment and human health due to its high concentration of ammonia nitrogen (NH3-N). It is therefore necessary and urgent to find a low-cost and convenient technique to remove high concentration of NH3-N from WREM. In this study, Natural powdered vermiculite (NV) was modified with seven sodium chloride (NaCl) solutions, and seven kinds of sodium chloride modified vermiculite (Na-V) were obtained. The NH3-N adsorption performance of Na-V is greatly improved compared with NV. Among them, vermiculite modified with 180 g/L NaCl yielded the highest ammonium adsorption capacity (Qm, 11.569 mg/g), which was 63.43% higher than NZ (Qm, 7.079 mg/g). The characterizations of 180-Na-V confirmed the removal mechanism of NH3-N that the improved capacity of modified vermiculite was attributed to its higher mesoporous volume and ion-exchange capacity, which are the result of sodium-ion exchange and Interlayer effect from high concentration of NaCl. The adsorption isotherms and kinetics were respectively best consistent with Langmuir model and the pseudo-second-order (PSO) model. The adsorption capacity (3.808 mg/g) of vermiculite after 5 cycles could still maintain 75.09% of the initial adsorption capacity (5.071 mg/g). A large amount of Na-V had little effect on pH of water, which meet the requirements of practical application. Including pH, dosage, coexisting ions, the effects of other factors on ammonium adsorption were also determined. This study provides a new method for vermiculite to remove high concentration of NH3-N.


Assuntos
Compostos de Amônio , Metais Terras Raras , Poluentes Químicos da Água , Adsorção , Silicatos de Alumínio , Amônia/química , Compostos de Amônio/química , Humanos , Concentração de Íons de Hidrogênio , Cinética , Nitrogênio , Cloreto de Sódio , Águas Residuárias/química , Poluentes Químicos da Água/análise
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