Erythropoietin protects newborn rat against sevoflurane-induced neurotoxicity.
BACKGROUND
Recent data on newborn animals exposed to anesthetics have raised safety concerns regarding anesthesia practices in young children. Indeed, studies on rodents have demonstrated a widespread increase in brain apoptosis shortly after exposure to sevoflurane, followed by long-term neurologic impairment. In this context, we aimed to evaluate the protective effect of rh-EPO, a potent neuroprotective agent, in rat pups exposed to sevoflurane.


METHODS
At postnatal day 7, 75 rat pups were allocated into three groups: SEVO + EPO (n = 27) exposed to sevoflurane 2 vol% (0.5 MAC) for 6 h in an air/O2 mixture (60/40) + 5000 UI.kg(-1) rh-EPO IP; SEVO (n = 27) exposed to sevoflurane + vehicle IP; and CONTROL (n = 21) exposed to the mixture without sevoflurane + vehicle IP. Three days after anesthesia (D10), apoptosis was quantified on brain extract with TUNEL method and caspase 3. NGF and BDNF expression was determined by Western blotting. Rats reaching adulthood were evaluated in terms of exploration capacities (object exploration duration) together with spatial and object learning (water maze and novel object test).


RESULTS
Sevoflurane exposure impaired normal behavior in adult rats by reducing the exploratory capacities during the novel object test and impaired both spatial and object learning capacities in adult rats (water maze, ratio time to find platform 3rd trial/1st trial: 1.1 ± 0.2 vs 0.4 ± 0.1; n = 9, SEVO vs CONTROL; P = 0.01). Rh-EPO reduced sevoflurane-induced behavior and learning abnormalities in adult rats (water maze, ratio time to find platform 3rd trial/1st trial: 0.3 ± 0.1 vs 1.1 ± 0.2; n = 9, SEVO + EPO vs SEVO; P = 0.01). Three days after anesthesia, rh-EPO prevented sevoflurane-induced brain apoptosis (5 ± 3 vs 35 ± 6 apoptotic cells·mm(-2) ; n = 6, SEVO + EPO vs SEVO; P = 0.01) and elevation of caspase three level and significantly increased the brain expression of BDNF and NGF (n = 6, SEVO + EPO vs SEVO; P = 0.01).


CONCLUSIONS
Six hours of sevoflurane anesthesia in newborn rats induces significant long-term cognitive impairment. A single administration of rh-EPO immediately after postnatal exposure to sevoflurane reduces both early activation of apoptotic phenomenon and late onset of neurologic disorders.
Department of Anesthesia, APHM, CHU Timone, Marseille, France; INSERM UMR_S 1076, Aix-Marseille University, Marseille, France.
Lionel
L
Pellegrini
Youssef
Y
Bennis
Lionel
L
Velly
Isabelle
I
Grandvuillemin
Pascale
P
Pisano
Nicolas
N
Bruder
Benjamin
B
Guillet
D018685:Anesthetics, Inhalation / Q000633:toxicity*; D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects; D001784:Blood Gas Analysis; D001921:Brain / Q000473:pathology; D003072:Cognition Disorders / Q000139:chemically induced / Q000517:prevention & control; D000068817:Epoetin Alfa; D004921:Erythropoietin / Q000627:therapeutic use*; D018782:Maze Learning / Q000187:drug effects; D008568:Memory / Q000187:drug effects; D008738:Methyl Ethers / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D009422:Nervous System Diseases / Q000139:chemically induced* / Q000517:prevention & control* / Q000523:psychology; D051381:Rats; D017207:Rats, Sprague-Dawley; D021641:Recognition, Psychology / Q000187:drug effects; D011994:Recombinant Proteins / Q000627:therapeutic use; D000077149:Sevoflurane
D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D011994:Recombinant Proteins; D004921:Erythropoietin; D000077149:Sevoflurane; D000068817:Epoetin Alfa
erythropoietin; neuroprotection; neurotoxicity; newborn; sevoflurane