Five percent, 7.5% or 10% hypertonic saline prevents delayed neuronal death in gerbils.
OBJECTIVE
To clarify the appropriate concentration and dose of hypertonic saline solution (HSS) for preventing delayed neuronal death in the hippocampal CA1 subfield after transient forebrain ischemia in gerbils.


METHODS
Thirty gerbils were randomly assigned to five groups: physiological saline solution (PSS) group, ischemia/reperfusion treated with PSS 2 mL x kg(-1); 5% HSS group, treated with 5% HSS 2 mL x kg(-1); 7.5% HSS group, treated with 7.5% HSS 2 mL x kg(-1); 10% HSS group, treated with 10% HSS 2 mL x kg(-1); 20% HSS group, treated with 20% HSS 2 mL x kg(-1). Transient forebrain ischemia was induced by occluding the bilateral common carotid arteries for four minutes. Five days later, histopathological changes in the hippocampal area were examined, and the degenerative ratio of the pyramidal cells were measured according to the following formula: (number of degenerative pyramidal cells/total number of pyramidal cells per 1 mm of hippocampal CA1 subfield) x 100.


RESULTS
In PSS and 20% groups, neuronal cell damage was observed five days after ischemia. In the other three groups, these changes were not observed. The degenerative ratios of pyramidal cells were as follows; PSS group: 91.6 +/- 5.6%, 5% HSS group: 7.2 +/- 1.6%, 7.5% group: 8.3 +/- 1.4%, 10% HSS group: 6.2 +/- 1.1%, 20% HSS group: 85.8 +/- 8.7% (P < 0.05; PSS and 20% HSS vs three other groups).


CONCLUSIONS
This study demonstrates that 5, 7.5 or 10% HSS 2 mL x kg(-1) may prevent delayed neuronal death in the hippocampal CA1 subfield after cerebral ischemia/reperfusion in gerbils.
Hamaguchi
Shinsuke
S
Department of Anesthesiology, Dokkyo University School of Medicine, Mibu, Tochigi, Japan. s-hama@dokkyomed.ac.jp
Okuda
Yasuhisa
Y
Kitajima
Toshimitsu
T
Masawa
Nobuhide
N
D000818:Animals; D002545:Brain Ischemia / Q000150:complications*; D016923:Cell Death / Q000187:drug effects; D005849:Gerbillinae; D006624:Hippocampus / Q000473:pathology*; D009422:Nervous System Diseases / Q000209:etiology; D009474:Neurons / Q000187:drug effects* / Q000473:pathology; D012462:Saline Solution, Hypertonic / Q000494:pharmacology*
D012462:Saline Solution, Hypertonic