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THE SUBCELLULAR LOCATION OF THE HIGHER ACETYLCHOLINE CONTENT IN RAT BRAIN FOUND AFTER KILLING BY THE NEAR‐FREEZING METHOD AS COMPARED WITH DECAPITATION 1
Author(s) -
Richter J. A.,
Shea P. A.
Publication year - 1974
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1974.tb12221.x
Subject(s) - acetylcholine , choline , acetylcholinesterase , fractionation , cell fractionation , chemistry , aché , biochemistry , chromatography , enzyme , biology , endocrinology
— We have confirmed the finding of T akahashi & A prison ( J. Neurochem. 11 , 887‐898, 1964) that more acetylcholine is found in brains of rats killed by near‐freezing compared to decapitation. The radioenzymic assays for acetylcholine and choline of S hea & A prison ( Analyt. Biochem. 56 , 165‐177, 1973) and G oldberg & M c C aman ( J‐ Neurochem. 20 , 1 8, 1973) were used to measure both compounds and gave very similar results. The larger amount of ACh was observed both in powders of frozen rat brain and in homogenates prepared from animals killed by near‐freezing. When subcellular fractionation of the homogenates was done in the presence of eserine, the larger amount of ACh was found in the soluble fraction (S 2 ). These results indicated that with the near‐freezing method, an extra amount of ACh is preserved in a form that is originally protected from acetylcholinesterase but that becomes esterase‐sensitive on fractionation since no differences were observed in P 1 . P 2 or S 2 fractions when no eserine was present. The amounts of choline in homogenates and subcellular fractions were also measured after both methods of killing. Differences in the method of killing and postmortem changes which affect the choline values obtained are described.