Oxidative damage and antioxidants in Rana sylvatica, the freeze-tolerant wood frog

Abstract

Freeze-tolerant wood frogs (Rana sylvatica) must endure prolonged ischemia on freezing. Reperfusion on thawing brings with it the potential or oxidative damage due to reactive oxygen species formation, a well-known consequence of mammalian ischemia-reperfusion. To determine whether oxidative damage occurs during thawing and how frogs deal with this, we examined oxidative damage and antioxidant and prooxidant systems in tissues of Rana sylvatica and a nonfreezing relative, Rana pipiens. Glutathione status indicated little oxidative stress in tissues during freezing or thawing; an increase of the glutathione pool in the oxidized form was observed during freezing only in Rana sylvatica kidney (by 85%) and brain (by 33%). Oxidative damage to tissue lipids, measured as the levels of thiobarbituric acid-reactive substances and/or by an Fe(III)-xylenol orange assay, did not increase above control values pver a freeze-thaw time course. Correlative data showing increased activities of some antioxidant enzymes during freezing, notably glutathione peroxidase (increasing 1.2- to 2.5-fold), as well as constitutively higher activities of antioxidant enzymes and higher levels of glutathione in the freeze-tolerant species compared with Rana pipiens, suggest that antioxidant defenses play a key role in amphibian freeze tolerance.

Antioxidant defense and stress protein induction following heat stress in the Mediterranean snailXeropicta derbentina[Pulmonata, Hygromiidae]

“…Changes in the activities of antioxidant enzymes have been found in many organisms in response to anoxia (Hermes-Lima and Storey, 1993;Hermes-Lima and Storey, 1996;Pannunzio and Storey, 1998;Lushchak et al, 2001), freezing (Hermes-Lima and Storey, 1993;Joanisse and Storey, 1996) and also Antioxidant defence and stress protein induction following heat stress in the Mediterranean snail Xeropicta derbentina Sandra Troschinski*, Andreas Dieterich, Stefanie Krais, Rita Triebskorn and Heinz-R. Köhler heat stress (Heise et al, 2006;Lushchak and Bagnyukova, 2006a;Verlecar et al, 2007). An increase in antioxidants during aestivation in snails (Hermes-Lima et al, 1998;Ramos-Vasconcelos and HermesLima, 2003;Nowakowska et al, 2009) has also been shown.…”

Hypoxia Tolerance in Animals: Biology and Application

“…Freeze exposure for 24 h in the wood frog Rana sylvatica prompted significant increases in Se-GPX and total-GPX activities in different tissues (Joanisse and Storey 1996). Increased expression of thioredoxin, glutathione S-transferase (GST), and glucose-6-phosphate dehydrogenase (G6PDH) in heart and g-glutamyltranspeptidase (g-GT) activity in liver were also observed for wood frogs under exposure to freezing (Hemmings and Storey 1996;Storey 2004).…”

Hypometabolism, antioxidant defenses and free radical metabolism in the pulmonate land snailHelix aspersa

“…Moreover, Se-GPX activity increased on sub-zero freezing (a hypometabolic condition that imposes ischemia on internal organs; Storey, 1996) in garter snakes (Hermes-Lima and Storey, 1993a) and wood frogs (Joanisse and Storey, 1996) and under severe dehydration in leopard frogs (50% loss of body water after 92 h, at 5°C, causing ischemia in internal organs; Hermes-Lima and . Moreover, Se-GPX activity from the hepatopancreas of the freshwater snail B. tenagophila (control activity, 10 mi.u.…”