title: Effects of perfluorinated amphiphiles on backward swimming in Paramecium caudatum.
abstract: PFOS and PFOA are ubiquitous contaminants in the environment. We investigated the effects of fluorochemicals on calcium currents in Paramecium caudatum using its behavioral changes. Negatively charged amphiphiles prolonged backward swimming (BWS) of Paramecium. PFOS significantly prolonged BWS, while PFOA was less potent (EC(50): 29.8+/-4.1 and 424.1+/-124.0microM, respectively). The BWS prolongation was blocked by cadmium, indicating that the cellular calcium conductance had been modified. The positively charged amphiphile FOSAPrTMA shortened BWS (EC(50): 19.1+/-17.3). Nonionic amphiphiles did not affect BWS. The longer-chain perfluorinated carboxylates PFNA and PFDA were more potent than PFOA (EC(50): 98.7+/-20.1 and 60.4+/-10.1microM, respectively). However, 1,8-perfluorooctanedioic acid and 1,10-perfluorodecanedioic acid did not prolong BWS. The critical micelle concentration (CMC) and BWS prolongation for negatively charged amphiphiles showed a clear correlation (r(2)=0.8008, p<0.001). In summary, several perfluorochemicals and PFOS and PFOA had similar effects in Paramecium, while chain length, CMC, and electric charge were major determinants of BWS duration.
authors.affiliation: Department of Health and Environmental Sciences, Kyoto University Graduate School of Medicine, Kyoto 6068501, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Matsubara
authors.forename: Kouji
authors.initials: K
authors.lastname: Harada
authors.forename: Kayoko
authors.initials: K
authors.lastname: Inoue
authors.forename: Akio
authors.initials: A
authors.lastname: Koizumi
mesh_terms: D017738:Alkanesulfonic Acids / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D002104:Cadmium / Q000494:pharmacology; D002210:Caprylates / Q000737:chemistry / Q000494:pharmacology*; D002244:Carbon / Q000737:chemistry; D005461:Fluorine / Q000737:chemistry*; D005466:Fluorocarbons / Q000737:chemistry / Q000494:pharmacology*; D015394:Molecular Structure; D009543:Nifedipine / Q000494:pharmacology; D048488:Paramecium caudatum / Q000187:drug effects* / Q000502:physiology*; D013329:Structure-Activity Relationship; D013550:Swimming / Q000502:physiology*
chemical_list: D017738:Alkanesulfonic Acids; D002210:Caprylates; D005466:Fluorocarbons; D002104:Cadmium; D005461:Fluorine; D002244:Carbon; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid; D009543:Nifedipine