Affiliations: Department of Pediatrics, Gazi University, Ankara,
Turkey | Department of Pediatric Surgery, School of Medicine,
Gazi University, Ankara, Turkey | Department of Pathology, School of Medicine, Hacettepe
University, Ankara, Turkey | Department of Pathology, School of Medicine, Baskent
University, Ankara, Turkey
Abstract: Purpose: The pre and post-treatment effects of L-carnitine on
apoptotic cell death due to hypoxia-ischemia in various regions of the brains
of seven-day-old rats were investigated. Methods: L-carnitine (group 1; n=8) or saline (group 2; n=8) was administered intraperitoneally to
seven-day-old rats before hypoxia-ischemia. In addition, 16 seven-day-old rats
were given L-carnitine (group 3; n=8) or saline (group 4; n=8) after
hypoxic ischemic insult. Apoptotic cell death was investigated by terminal
dUDP-biotin nick end-labeling (TUNEL) in all subjects following three days of
recovery. In the evaluation of TUNEL- positive cells, firstly the areas (in
square millimeters) of the hippocampus, striatum and cortex in the right and
left hemispheres were measured by IMAGE analysis. Then the numerical density
was calculated as the number of cells per square millimeter by counting all
TUNEL- positive cells. Afterwards, the ratios of right side numerical density
to the sum of right and left sides' numerical densities (right apoptosis index)
were calculated for every brain region in rats receiving L-carnitine and they
were compared with the vehicle groups. Results: The right apoptosis indexes of the hippocampus (37.4 ± 18.8; mean ± SD) and striatum
(39.2 ± 15.2) in rat pups pre-treated with L-carnitine were significantly
lower than those in the vehicles (59.8 ± 17.9 vs. 60.4 ± 19.6
respectively) (p< 0.05), whereas they were not changed by L-carnitine
pre-treatment in the cortex. Additionally, L-carnitine post-treatment had no
effect on right apoptosis indexes in any of the three brain regions. Conclusions: It is concluded that pre-treatment with L-carnitine might play a
role in reducing apoptotic cell death due to neonatal hypoxic ischemic brain
injury. Our results suggested that L-carnitine was useful in perinatal asphyxia
for preventing hypoxic ischemic brain injury.
Keywords: Apoptosis, newborn rat, hypoxia-ischemia, carnitine, regional, hippocampus, striatum, cortex
