Physiological differences in the crab Ucides cordatus from two populations inhabiting mangroves with different levels of cadmium contamination

Abstract

Crustaceans found in metal-contaminated regions are able to survive, and the authors investigated the physiological mechanisms involved by comparing populations from contaminated and noncontaminated areas. The objective of the present study was to measure the cellular transport of a nonessential metal (cadmium [Cd]) in gills and hepatopancreas of Ucides cordatus, together with cell membrane fluidity, metallothionein levels, and lipid peroxidation. The 2 populations compared were from a polluted and a nonpolluted mangrove area of São Paulo State, Brazil. The authors found, for the first time, larger Cd transport in gills and hepatopancreatic cells from crabs living in polluted mangrove areas. The cells also had lower plasma membrane fluidity, increased lipid peroxidation and less metallothionein compared to those from nonpolluted regions. The authors also found larger amounts of Cd in intracellular organelles of gills, but not in the hepatopancreas, from crabs in polluted regions. Therefore, in polluted areas, these animals showed higher Cd transport and lower plasma membrane fluidity and storage of Cd intracellularly in gill cells, whereas hepatopancreatic cells used metallothionein as their main line of defense. The findings suggest that crabs from polluted areas can accumulate Cd more easily than crabs from nonpolluted areas, probably because of an impairment of the regulatory mechanisms of cell membrane transport. Environ Toxicol Chem 2017;36:361-371. © 2016 SETAC.

Lipid Peroxidation in Hepatopancreas, Gill, and Hemolymph of Male and Female Crabs Platyxanthus orbignyi after Air Exposure

“…Immediately, the living animals were brought to the Universidad Nacional de Ingeniería (Lima campus), being transported for 1 h at 22 • C ± 1. The individuals were divided into four groups: (i) Female crabs for control (9.6 ± 1.0 cm, 176 ± 28 g, n = 5) in seawater, (ii) male crabs for control (9.5 ± 0.4 cm, 163 ± 13 g, n = 5) in seawater, (iii) male crabs on-air exposure (7.3 ± 0.7 cm, 104 ± 20 g, n = 7) and (iv) female on-air exposure (7.2 ± 0.3 cm, 113 ± 14 g, n = 7) [15].…”

“…HP and G samples were collected in plastic Eppendorf (1.5 mL) and immediately, weighed (0.03-0.05 g) and frozen at −20 • C to avoid LPO decomposition. HYM (100-150 µL) was collected in plastic Eppendorf (1.5 mL), using sterile insulin syringes (500 µL) to penetrate the intersegmental membrane between the posterior of the carapace and the coxa of the leg, previously disinfected with alcohol 70% (Aldrich, USA) [15], and was immediately added to methanol 100% (1:9 ratio, sample:methanol), previously cooled at 5 • C, after that, the methanolic suspensions were homogenized using vortex, and stored at -20 • C.…”

“…Biochemical analysis. The LPO levels in HP, G, and HYM were assessed by a modified Fox method as hydrogen peroxide equivalents (Eq-H 2 O 2 ) [9,[15][16][17]. Hydrogen peroxide was used considering its greater reactivity in the FOX method (100%) compared to t-Butyl hydroperoxide (96%), cumene hydroperoxide (98%), di-cumyl peroxide (12%), benzoyl peroxide (9 %), and lauroyl peroxide (21%).…”

“…Kruskal-Wallis one-way analysis of variance on ranks was performed to determinate LPO levels on each condition to air exposure. Data were checked for normality and homogeneity of variance by Holm-Sidak test performed with Stat 3.2 software (Systat Software, San Jose, CA, USA) [15]. Significant differences (p < 0.05) were compared using the Tukey post hoc test [18].…”

Chapter 10. The Crab Ucides cordatus (Malacostraca, Decapoda, Brachyura) and Other Related Taxa as Environmental Sentinels for Assessment and Monitoring of Tropical Mangroves from South America

“…Ucides cordatus has been used for physiological studies related to toxic metal transport using both gills and hepatopancreas cells as tissue targets. [96][97][98] In general, both Cu and Cd are transported through cell membrane transporters that involve carriers associated with calcium transport. 97,98 Posterior gills, which are responsible for ion transport, compared to the respiratory role of anterior gills, transport and accumulate more toxic metals compared to anterior gills.…”