Direct Effect of Inorganic Mercury on Citrate Uptake by Isolated Rat Renal Brush Border Membrane Vesicles

• Published in: Industrial Health Vol. 35; no. 4; pp. 456 - 460
• Main Authors: SATO, Kazuhiro, KUSAKA, Yukinori, ZHANG, Qunwei, DEGUCHI, Yoji, LI, Benyi, OKADA, Kenichiro, NAKAKUKI, Kazuya, MURAOKA, Ryusuke
• Format: Journal Article
• Language: English
• Published: Japan National Institute of Occupational Safety and Health 01.10.1997
• Subjects: Animals; Brush border membrane vesicles (BBMV); Citrate; Citric Acid - metabolism; Dose-Response Relationship, Drug; In Vitro Techniques; Kidney Cortex - drug effects; Kidney Cortex - metabolism; Kidney Cortex - ultrastructure; Male; Mercury; Mercury - pharmacokinetics; Mercury - toxicity; Microvilli - drug effects; Microvilli - metabolism; Rats; Rats, Wistar; Time Factors
• ISSN: 0019-8366; 1880-8026
• DOI: 10.2486/indhealth.35.456

Occupational exposure to mercury has long been associated with renal proximal injury and an increased incidence of proteinuria, as has such exposure to cadmium. Renal citrate excretion is very important with respect to acid-base balance since the metabolism of citrate generates three bicarbonate ions. In this study, we exposed isolated rat renal brush border membrane vesicles (BBMV) to mercury (Hg2+) and examined their citrate uptake characteristics. BBMV were prepared by the divalent cation precipitation method. Citrate uptake was measured by the Millipore rapid membrane filtration method. The preincubation of BBMV with 0.5 and 2mM HgCl2 for 1min significantly inhibited citrate uptake compared with that of BBMV without Hg preincubation. The analysis of the time course of citrate uptake during a 30-min preincubation of BBMV with 0.1mM Hg2+ also revealed a significant reduction in the uptake compared with that of the control BBMV without preincubation. These findings indicate that the preincubation of BBMV with mercury results in a time- and concentration-dependent inhibition of citrate uptake.