Morphological, biochemical, and histopathological indices and contaminant burdens of cotton rats (Sigmodon hispidus) at three hazardous waste sites near Houston, Texas, USA

Environmental contaminants in redheads wintering in coastal Louisiana and Texas

“…Our values of pristane and total HCs were higher than values (pristane: mean = 0.028, max = 0.08 Ixg/g wet mass; total HCs: mean = 0.820, max = 1.40 txg/g wet mass) in cotton rats (Sigmodon hispidus) from a contaminated petroleum waste site (Rattner et al 1993). These differences could be related to the tendency of some contaminants to be more persistent, and more toxic, in birds than in mammals because birds have lower activity levels of some enzymes important in breaking down and clearing toxicants from the body (Walker and E1 Zorgani 1974;Brealey et al 1980;Westlake et al 1983).…”

“…Pristane and phytane are branchchained compounds that occur commonly in petroleum pollutants and may be metabolized less readily than straight-chained configurations (Hall and Coon 1988). Therefore, we calculated the ratios of pristane:n-heptadecane, phytane:n-octadecane, and pristane:phytane under the assumption that ratio values of > 1, for the first two terms, would indicate chronic exposure to petroleum pollutants (Hall and Coon 1988;Rattner et al 1993). We also calculated total AHs, total PAHs, and total HCs as the sum of all detectable compounds in each group (Rattner et al 1993).…”

Cellular immune responses of nutritionally stressed juvenile cotton rats (Sigmodon hispidus) during acute benzene exposure

“…Cyclophosphamide and also crude protein restriction induced severe immune lesions manifested as thymus and spleen atrophy, depressed delayed hypersensitivity response, reduced proliferative capacity of splenocytes, and reduced numbers of total leukocytes, lymphocytes, and splenocytes. Although severe immune modulation resulted from the individual effects of CY exposure and dietary protein restriction, there was little statistically significant toxicant-diet interaction.Development of biomarkers to assess exposure of organisms to environmental contaminants is increasing, and studies utilizing wild rodent models are becoming more common in the literature (Rowley et al 1983;McBee et al 1987;Batty et al 1990;Flickinger and Nichols 1990;Rattner et al 1993). Numerous approaches including biochemical, physiological, and histological changes in organisms have proven useful for documenting exposure to xenobiotics.…”

Indicators of Immunotoxicity in Populations of Cotton Rats (Sigmodon hispidus) Inhabiting an Abandoned Oil Refinery

“…Overall, organ mass tended to be lower and erythrocyte parameters higher in cotton rats collected from contaminated than reference sites. Effects of hazardous waste products on liver mass in wild cotton rats have been reported with variable results ranging from no detectable differences (Elangbam et al, 1989) to both increased and decreased mass (Rattner et al, 1993). Laboratory rodent studies have revealed decreased adrenal mass (Chowdhury et al, 1986) and increased spleen mass (Cory-Slechta, 1990) following lead exposure.…”

“…Endpoints in these studies were typically limited to measurement of uptake and accumulation of toxicants in selected tissues. More recently, the development of biomarkers in laboratory animals and, to a lesser extent, free-ranging wildlife has led to use of biomarkers in assessment of toxicant-induced alterations in boichemical and physiological function, histology and gross morphology of tissue, chromosome morphology, and population and community dynamics (McBee et al, 1987;Batty et al, 1990;Flickinger and Nichols, 1990;Rattner et al, 1993).…”