Guinea Pig Pulmonary Mechanics: Altered Sensitivity to Carbachol by Cadmium and/or Selenium

Abstract

Male Hartley guinea pigs (480-610 g) were treated intratracheally as follows: saline, cadmium (Cd, 0.3 mg), selenium (Se, 0.3 or 0.06 mg), or Se (0.06 mg) and Cd (0.3 mg) simultaneously. Selenium and Cd were administered as sodium selenite and cadmium chloride, respectively. Twenty-four h later, dynamic lung compliance (Cdyn) and pulmonary resistance (Rp) were measured before (baseline Cdyn and Rp) and after carbachol administration (0.0001, 0.001, 0.01, and 0.1 mumol/kg, intravenously). Results indicated a significant decrease in baseline Cdyn caused by 0.3 mg of Cd, 0.3 mg or 0.06 mg of Se, and 0.3 mg of Cd with 0.06 mg of Se (p < 0.05). A significant increase in baseline Rp due to 0.3 mg of Se was observed (p < 0.05). Carbachol decreased Cdyn significantly below baseline, evident after lower doses of carbachol, in guinea pigs pretreated with 0.3 mg of Se, whereas a significant improvement in Cdyn was seen after 0.0001 mumol/kg carbachol in the group pretreated with Se and Cd simultaneously (p < 0.05) compared with the respective baseline values of the saline-treated group. Similarly, a significant increase in Rp was observed after carbachol in groups pretreated with 0.3 mg of Cd or Se (p < 0.05). Results also indicated a significant increase in large airway constriction caused by Cd and/or Se (p < 0.05). A leftward shift in the carbachol dose-response curve indicated increased sensitivity to carbachol in Cd- and/or Sepretreated guinea pigs.

Changes in Bronchoalveolar Lavage Cells after Intratracheal Instillation of Dimethyl Selenide in Mice

“…In a recent study, we have characterized by light microscopy the DMSe-induced lesions observed in trachea and lungs of treated mice (Cherdwongcharoensuk et al, 2003). The current investigation offers a rationale for the pathology that we and others have reported in respiratory tissues after DMSe instillation (Bell et al, 1997(Bell et al, , 1998Nonavinakere et al, 1999, Cherdwongcharoensuk et al, 2003. In fact, the present observations indicate that inflammatory neutrophils and macrophages are likely mediators of the alterations caused in respiratory tissues by the presence of Se in the airways.…”

“…Most of the studies on the toxicology of selenium (Se) have used oral ingestion (Nantel et al, 1985;Pentel et al, 1985;Köppel et al, 1986;Matoba et al, 1986;Gasmi et al, 1997). Only a few investigations have documented that Se inhalation is harmful for the airways and lungs (Bell et al, 1997a(Bell et al, , 1997b(Bell et al, , 1998Nonavinakere et al, 1999;Cherdwongcharoensuk et al, 2003). Human exposure to airborne Se may occur accidentally from several industrial activities.…”