Effects of Acute and Chronic Cadmium Administration on the Vascular Reactivity of Rat Aorta

Abstract

The effect of acute and chronic cadmium (Cd) administration on the vascular function of the rat aorta was studied. The rats were randomly divided into four main groups (A: saline controls under chronic administration, B: Cd-treated rats under chronic administration, C: saline controls under acute administration, D: Cd-treated rats under acute administration). After their sacrifice, the aortic rings were divided into rings with endothelium (E+) and without (E-), and suspended in an isolated organ bath with Krebs - Henseleit buffer. Maximal tension (T max, in g) was measured in response to potassium chloride (KCl) and phenylephrine (PE) in all aortic rings. Relaxation response to acetylcholine (ACh) administration was expressed as percent of maximal tension induced by PE. Chronic administration: A statistically significant increase of the contraction was observed between groups B (i.m. Cd 0.5 mg/kg for 120 days) and A (i.m. 0.9% NaCl for 120 days) in response to KCl (20-60 mM) and the T max as well (in both the E+ and the E- subgroups). No statistically significant difference was observed in response to PE and ACh exposure. Acute administration: A statistically significant increase was observed between group D(E+) (i.m. Cd 2 mg/kg, 8 h before sacrifice) and group C(E+) (i.m. 0.9% NaCl, 8 h before sacrifice) in response to 10-30 mM of KCl, and a significant decrease between D(E-) and C(E-) in response to 10(-7)-10(-6) M of PE, though T (max) was increased between D(E-) and C(E-) with PE exposure. The contractile response levels of the E+ aortic rings to PE and ACh showed no statistically significant difference.

Protective Effect of Guaraná (Paullinia cupana var. sorbilis) Pre-treatment on Cadmium-Induced Damages in Adult Wistar Testis

“…Histological observations and stereological analysis results showed that Cd group presented a slight reduction in blood vessel lumen relative to control animals. This vasoconstriction due to cadmium toxicity has also been described in preceding literature [29,30] and could be explained, at least in part, by the observations that this cation induces intracellular oxidative stress, resulting in decreased nitric oxide synthesis [29,31] and consequent reduction in vasodilation. In contrast, group PcCd and group Pc presented an evident increase in blood vessel lumens relative to control animals.…”

Tetrahydrocurcumin Protects against Cadmium-Induced Hypertension, Raised Arterial Stiffness and Vascular Remodeling in Mice

“…We found that Cd induced vascular dysfunction by attenuating the response of VSMC to vasoactive agents. The blunted response of Phe-induced contraction reported here may be explained by Cd provoking enhanced Ca 2+ - channel antagonism and thus, resulting in the reduction of Phe contraction [44] . The suppression of the vascular response to ACh after Cd exposure can be explained by decreasing endothelium-dependent vaso-relaxation which is due to down-regulation of eNOS expression, as found in this study, as well as an NO-dependent pathway dysfunction in the vascular endothelium [15] .…”

Advantage of Guaraná (Paullinia cupana Mart.) Supplementation on Cadmium-induced Damages in Testis of Adult Wistar Rats

“…This result shows that the deleterious effects of cadmium in blood vessels are time-dependent and progressive. Vasoconstriction in animals exposed to cadmium was also reported in preceding literature (Skoczynska and Martynowicz 2005;Tzotzes et al 2007), and could be explained, at least partially, by the observation that this metal induces intracellular oxidative stress, resulting in decreased nitric oxide synthesis (Skoczynska and Martynowicz 2005).…”