Acid exposure is an immune disruptor in adult Rana pipiens

Abstract

Abstract-Acidic environments are physiological stressors for amphibians. The objective of the present study was to document the effect of an acidic environment on innate immune system function under controlled experimental conditions in Rana pipiens. We developed an in vivo assay, by injecting a suspension of 1-m fluorescent beads in fluid thioglycollate, to induce peritonitis. The number of peritoneal exudate leukocytes and their phagocytic activity did not increase with thioglycollate injection when frogs were exposed to pH 5.5 compared to when frogs were exposed to pH 7.0. An environment of pH 5.5 disrupted the inflammatory response of frogs compared to an environment of pH 7.0; at pH 5.5, more nonphagocytic leukocytes and fewer highly phagocytic leukocytes were found compared to those in frogs exposed to pH 7.0. Frogs stimulated by thioglycollate injection and exposed to pH 5.5 had a 50% increase in cells that did not exhibit phagocytosis and a 4-to 10-fold reduction in the number of highly phagocytic cells. This is evidence that acid exposure functions as an immune disruptor in adult R. pipiens under laboratory conditions.

Ion fluxes across the pitcher walls of three Bornean Nepenthes pitcher plant species: flux rates and gland distribution patterns reflect nitrogen sequestration strategies

“…bicalcarata (J Moran, personal observation). Both groups of animals are known to be intolerant of hyperacidic conditions (Diesel, 1992; Vatnick et al , 2006). …”

Atrazine is an immune disruptor in adult northern leopard frogs (Rana pipiens)

“…1); acid exposed results are from a previous experiment [10] and are presented here only for comparison between environmental contaminants. These results are very similar to frogs that were exposed to acid (Fig.…”

“…Control groups were injected with an iso-osmotic Ringer solution. Acid exposure data are from a previous experiment [10]. Statistical significance ( p Ͻ 0.05) is indicated by different letters.…”

“…This concentration is 30 times higher than the 0.1 ppb that Hayes et al [6,8] showed to cause feminization of male frogs in the laboratory. We hypothesized that atrazine, even at as low a concentration as 0.1 ppb, may act as an immune disruptor in similar ways to mild acid exposure, that is, by disrupting the innate immune response of adult R. pipiens (SETAC Globe, 2004, 5:48-49; [10]). We hypothesized that atrazine, even at as low a concentration as 0.1 ppb, may act as an immune disruptor in similar ways to mild acid exposure, that is, by disrupting the innate immune response of adult R. pipiens (SETAC Globe, 2004, 5:48-49; [10]).…”

“…on the innate immune response in adult R. pipiens at doses similar to those that disrupt endocrine function. We hypothesized that atrazine, even at as low a concentration as 0.1 ppb, may act as an immune disruptor in similar ways to mild acid exposure, that is, by disrupting the innate immune response of adult R. pipiens (SETAC Globe, 2004, 5:48-49; [10]). To assess the innate immune response, we stimulated frogs with thioglycollate, a widely used inflammatory mediator [11][12][13][14][15].…”