Gerbil forebrains were frozen in situ to inactivate the tissues, and 1,2-diacylglycerols were first measured quantitatively by HPLC. Although 1,2-diacylglycerols were completely recovered from the HPLC column, the control amount of
1,2-diacylglycerol in gerbil forebrain was only 79.6 nmol/g wet weight, which is about one-fourth of that previously reported for gerbil brain inactivated by liquid N2 after
decapitation instead of in situ freezing. The
fatty acid composition of 1,2-diacylglycerols in gerbil forebrain was first reported and the control 1,2-diacylglycerols were richer in
palmitic acid than in
stearic acid or
arachidonic acid, which is rather different from the data previously reported for mouse or rat brain obtained by
decapitation and analyzed by traditional TLC methods. The amount of
1,2-diacylglycerol increased by 82.9% in gerbil forebrain during 5 min of
ischemia induced by bilateral carotid
ligation.
Arachidonic acid and
stearic acid were abundant in the 1,2-diacylglycerols produced by 5 min of
ischemia. Thus we were able to obtain accurate values of the amount and the
fatty acid composition of 1,2-diacylglycerols in gerbil forebrains using HPLC and in situ freezing technique.