| atrazine concentrations, gonadal gross morphology and histology in ranid frogs collected in michigan agricultural areas. | the triazine herbicide atrazine has been suggested to be a potential disruptor of normal sexual development in male frogs. the goals of this study were to collect native ranid frogs from sites in agricultural and non-agricultural areas and determine whether hypothesised atrazine effects on the gonads could be observed at the gross morphological and histological levels. juvenile and adult green frogs (rana clamitans), bullfrogs (r. catesbeiana) and leopard frogs (r. pipiens) were collected in the ... | 2006 | 16300839 |
| plasma steroid hormone concentrations, aromatase activities and gsi in ranid frogs collected from agricultural and non-agricultural sites in michigan (usa). | the triazine herbicide atrazine has been hypothesized to disrupt sexual development in frogs by up-regulating aromatase activity, resulting in greater estradiol (e2) concentrations and causing feminization in males. the goal of this study was to collect native ranid frogs from atrazine-exposed ponds and determine whether relationships exist between measured atrazine concentrations and the gonadosomatic index (gsi), plasma concentrations of testosterone (t), e2 or 11-ketotestosterone (kt), or wit ... | 2006 | 16427146 |
| sediment tcdd-eqs and erod and mrod activities in ranid frogs from agricultural and nonagricultural sites in michigan (usa). | in vitro studies have demonstrated atrazine-mediated induction of 7-ethoxyresorufin o-deethylase (erod) activity. erod is an enzyme active in the metabolism of many compounds, including many xenobiotics. these studies have suggested that atrazine may affect reproductive function by altering steroid metabolism. the goal of this study was to determine whether relationships could be detected between measured atrazine concentrations in surface waters and the liver-somatic index (lsi) and erod and 7- ... | 2006 | 16788744 |
| helminth infracommunities of the frogs rana catesbeiana and rana clamitans from turkey marsh, michigan. | one hundred twenty-seven bullfrogs, rana catesbeiana, and 120 green frogs, rana clamitans, collected in july and august 1987 from turkey marsh, michigan, were examined for helminths. of the 16 helminth species found, falcaustra catesbeianae had the highest prevalence and mean intensity in bullfrogs. in green frogs, megalodiscus temperatus had the highest prevalence and haematoloechus parviplexus had the highest mean intensity. taxonomically, 1,030 (30.5%) trematodes and 2,348 (69.5%) nematodes o ... | 1991 | 2040950 |