The effects of cadmium on zinc absorption in isolated rat intestinal preparations

Abstract

The effect of cadmium on zinc absorption was studied using an isolated vascularly and luminally perfused rat intestinal preparation. 65Zn as well as Zn and Cd (both as the chloride salt) were added to the luminal perfusion medium (LPM) at varying concentrations. Over a 90-min period, the amount of Zn appearing in the vascular perfusion medium (VPM) and that retained by the tissue post-perfusion was estimated. Cd at all levels studied (0.03, 0.10, 1.0, and 10.0 micrograms/mL) reduced the amount of Zn appearing in the VPM in comparison with control perfusions (no detectable Cd in the LPM) when the initial Zn concentration was 5 micrograms/mL. Similarly, with an initial Zn concentration of 10 or 20 micrograms/mL, the amount of Zn appearing in the VPM was reduced when the Cd concentration was 0.1 or 1.0 micrograms/mL. With these same Zn concentrations, the amount of Zn retained by the tissue was higher when the Cd concentration was 10 micrograms/mL. These results demonstrate that Cd at low concentrations is capable of reducing Zn appearance in the VPM.

The environment and male reproduction: The effect of cadmium exposure on reproductive function and its implication in fertility

“…Interference between Cd and Zn occurs at multiple levels: intestinal absorption, bioavailability, tissue distribution, and faecal and urinary excretion [14,15,93]. In ex vivo isolated rat intestine preparations, treatment with Cd, even at low levels of exposure, was demonstrated to inhibit Zn intestinal absorption [94]; moreover, in a study on human subjects exposed to Cd, bpCd was associated to a significant decrease, despite remaining within the normal range, of serum Zn concentrations [95]. On the other hand, Zn was shown to exert protective effects from Cd poisoning, by reducing its intestinal absorption and retention, as confirmed by experimental in vivo studies in birds exposed to Cd and fed adequate-Zn or low-Zn diets [96], and by reducing Cd accumulation in blood and in several organs and tissues, including the testis [97][98][99].…”

Impacts of cadmium on male fertility: Lessons learnt so far

“…Cd has been able to achieve ionic interference by modifying absorption, bioavailability, distribution and excretion of the ions (Bridges & Zalups, 2005). At very low exposure of rats intestine to Cd in vivo, Zn absorption was inhibited (Coppen‐Jaeger & Wilhelm, 1989). Significant reduction of blood plasma concentration of Cd in humans equivalent to the normal range of Zn concentration in the serum upon exposure to Cd (Pizent et al, 2003).…”

Effect of Dietary Cadmium Levels on Nutrient Digestibility and Retention of Iron, Copper and Zinc in Tissues of Growing Pigs

“…The interaction among essential and toxic metals is a significant aspect of trace metal metabolism. Many studies showed that cadmium could interfere with the transport and metabolism of many essential metals, such as iron, zinc and copper (Davies and Campbell, 1977;Webster, 1979;Coppen-Jaeger and Wilhelm, 1989;Kozlowska et al, 1993;Oishi et al, 2000). There is some evidence that several essential metals can inhibit cadmium absorption in the intestine (Foulkes, 1985).…”