RESUMEN

Dichlorvos (DDVP), an organophosphorus pesticide is a volatile compound which enters the human body through oral, dermal and inhalational routes and is excreted via the kidney. This study assessed the effects of DDVP on the histology of the kidney. Twenty five male rats (75.05 ± 5.55 g) were divided into 5 groups of 5 rats per group as follows: Unexposed group, exposure to DDVP alone for 5 weeks, and 3 other groups exposed to DDVP for 5 weeks in addition to supplement with Vitamin E, vitamin C, and red palm oil (RPO). Rats were exposed to DDVP in poorly ventilated cardboard cages for 4 hours daily. On completion of exposure, rats were euthanized and tissue processed by routine paraffin wax method and stained with H&E. Morphological alterations monitored by histological and morphometric studies using the graticule and software packages. Data were analyzed with ANOVA and p<0.05 considered as significant. DDVP caused significant reduction (10%) in the maximum glomerular diameter and 18% reduction in the maximum width of the renal corpuscle when compared with unexposed rats. However, VTE, VTC, and RPO significantly elevated the maximum glomerular diameter by 21%, 22%, 23% the respectively. Similarly, VTE, VTC, and RPO significantly elevated the maximum width of the renal corpuscle by 17%, 19%, 20% respectfully. Glomerular tuft cellularity was neither affected by DDVP treatment nor by vitamin augmentation. Inhaled DDVP caused histological alterations in the microscopic anatomy of renal corpuscles of rat which was mitigated by vitamin supplementation. Data suggest involvement of prolonged DDVP use in the aetiology of renal failure.

El diclorvos (DDVP), un pesticidas organofosforado, es un compuesto volátil que entra en el cuerpo humano a través de la vía oral, dérmica y por rutas inhalación, excretándose por vía renal. Este estudio evaluó los efectos histológicos del DDVP sobre el riñón. Veinticinco ratas machos (75,05±5,55 g) se dividieron en 5 grupos de 5 ratas cada uno: grupo no expuesto, expuesto a DDVP durante 5 semanas, y otros 3 grupos expuestos a DDVP durante 5 semanas, suplementados con vitamina E (VTE), vitamina C (VTC) y aceite de palma roja (APR). Las ratas fueron expuestas a DDVP en jaulas de cartón con poca ventilación por 4 horas diarias. Al término de la exposición, las ratas se sacrificaron y el tejido fue procesado para inclusión en parafina y tinción con H&E. Las alteraciones morfológicas se evaluaron mediante estudios histológicos y morfométricos utilizando retículas y software. Los datos se analizaron con la prueba ANOVA considerado un p<0,05 como significativo. El DDVP causó una reducción significativa (10%) en el diámetro máximo glomerular y ancho máximo del copúsculo renal (18%), en comparación con las ratas no expuestas. Sin embargo, el diámetro máximo glomerular fue significativamente elevado con VTE, VTC y APR en 21%, 22% y 23%, respectivamente, así como para el ancho máximo del corpúsculo renal por 17%, 19% y 20%, respectivamente. La celularidad de la red glomerular no fue afectada por el DDVP ni aumentó con el tratamiento de vitamina. El DDVP inhalado provocó alteraciones histológicas en la anatomía microscópica de los corpúsculos renales de rata, las que fueron mitigadas por la suplementación de vitamina. Los datos sugieren relación entre la exposición prolongada a DDVP y la etiología de la insuficiencia renal.

Asunto(s)

RESUMEN

We report here that the surface topography of colloidal mesoporous silica nanoparticles (MSNs) plays a key role on their bionano-interactions by driving the adsorption of biomolecules on the nanoparticle through a matching mechanism between the surface cavities characteristics and the biomolecules stereochemistry. This conclusion was drawn by analyzing the biophysicochemical properties of colloidal MSNs in the presence of single biomolecules, such as alginate or bovine serum albumin (BSA), as well as dispersed in a complex biofluid, such as human blood plasma. When dispersed in phosphate buffered saline media containing alginate or BSA, monodisperse spherical MSNs interact with linear biopolymers such as alginate and with a globular protein such as bovine serum albumin (BSA) independently of the surface charge sign (i.e. positive or negative), thus leading to a decrease in the surface energy and to the colloidal stabilization of these nanoparticles. In contrast, silica nanoparticles with irregular surface topographies are not colloidally stabilized in the presence of alginate but they are electrosterically stabilized by BSA through a sorption mechanism that implies reversible conformation changes of the protein, as evidenced by circular dichroism (CD). The match between the biomolecule size and stereochemistry with the nanoparticle surface cavities characteristics reflects on the nanoparticle surface area that is accessible for each biomolecule to interact and stabilize any non-rigid nanoparticles. On the other hand, in contact with variety of biomolecules such as those present in blood plasma (55%), MSNs are colloidally stabilized regardless of the topography and surface charge, although the identity of the protein corona responsible for this stabilization is influenced by the surface topography and surface charge. Therefore, the biofluid in which nanoparticles are introduced plays an important role on their physicochemical behavior synergistically with their inherent characteristics (e.g., surface topography).

Asunto(s)