The effects of oil exposure and weathering on black-needle rush (Juncus roemerianus) marshes along the Gulf of Mexico.

Oil exposure has been shown to be detrimental to several salt marsh plants however little information is available for Juncus roemerianus. Thirty-two mesocosms were established with J. roemerianus sod and replicate marshes were exposed to Louisiana sweet crude oil to test oil dose (6, 12, and 24 L m⁻²) and weathering (oil weathered for 0 days, 3 days, and 3 weeks). Juncus were monitored following oil exposure for culm survival, photosynthetic rates, and C-assimilation rates. Oil dosage had a significant effect among wetlands with low-dose (6 L m⁻²) mesocosms having higher culm survival, photosynthetic rates, and C-assimilation rates than medium or high dose wetlands (12 or 24 L m⁻²). Oil weathering did not elicit significant differences between treated wetlands however full strength wetlands (un-weathered oil) consistently had the lowest culm survivorship, photosynthetic rates, and C-assimilation rates. From our results, J. roemerianus marshes may be very susceptible to oil exposure.

In vivo characterization of the mitochondrial selective K(ATP) opener (3R)-trans-4-((4-chlorophenyl)-N-(1H-imidazol-2-ylmethyl)dimethyl-2H-1-benzopyran-6-carbonitril monohydrochloride (BMS-191095): cardioprotective, hemodynamic, and electrophysiological effects.

Recent studies have shown the importance of mitochondrial ATP-sensitive potassium channels (K(ATP)) in cardioprotection, and studies in vitro have shown that the benzopyran analog (3R)-trans- 4-((4-chlorophenyl)-N-(1H-imidazol-2-ylmethyl)dimethyl-2H-1-benzopyran-6-carbonitril monohydrochloride (BMS-191095) is a selective mitochondrial K(ATP) opener with cardioprotective activity. The goal of this study was to show selective cardioprotection for BMS-191095 in vivo without hemodynamic or cardiac electrophysiological effects expected for nonselective K(ATP) openers. BMS-191095 reduced infarct size in anesthetized dogs (90-min ischemia + 5-h reperfusion) in a dose-dependent manner (ED(25) = 0.4 mg/kg i.v.) with efficacious plasma concentrations of 0.3 to 1.0 microM, which were consistent with potency in vitro. None of the doses of BMS-191095 tested caused any effect on peripheral or coronary hemodynamic status. Further studies in dogs showed no effects of BMS-191095 on cardiac conduction or action potential configuration within the cardioprotective dose range. In a programmed electrical stimulation model, BMS-191095 showed no proarrhythmic effects, which is consistent with its lack of effects on cardiac electrophysiological status. BMS-191095 is a potent and efficacious cardioprotectant that is devoid of hemodynamic and cardiac electrophysiological side effects of first generation K(ATP) openers, which open both sarcolemmal and mitochondrial K(ATP). Selective opening or activation of mitochondrial K(ATP) seems to be a potentially effective strategy for developing well tolerated and efficacious K(ATP) openers.