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Biomedical subjects

P I Szilagyi

Publications and source records attributed to P I Szilagyi.

11 recordsLinked to original sources
PubMed1981

Simultaneous measurement of acetylcholine and choline in brain by pyrolysis-gas chromatography-mass spectrometry.

Pyrolysis-gas chromatography and chemical ionization mass fragmentography were combined to develop a specific, simple and rapid method for simultaneously measuring endogenous and stable isotopic variants of acetylcholine and choline with a detection limit of approximately 10(-12) mol. The recovery and reproducibility of the method are excellent, and the method is suitable for measuring acetylcholine and choline in discrete regions of rat brain and to measure incorporation of choline into acetylcholine, both of which uses are demonstrated. This method affords easy analysis of 40 samples in a working day. The new technique used to extract compounds from tissues and the modified gas flow arrangement may be useful to measure other compounds as well.

Acetylcholine↗
PubMed1976

Acute effects of morphine on regional brain levels of acetylcholine in mice and rats.

Morphine increased levels of acetylcholine in mouse striatum in a dose-dependent manner, the increase occurring at the lowest dose previously found to produce analgesia and coinciding with the time of peak analgesic effect. Naloxone blocked this increase. After repeated injections of high doses of morphine, no effect was seen. The hippocampus was the only other brain region showing an effect, and this after a high dose. In the rat, morphine (30 and 90 mg/kg) increased striatal acetylcholine levels. At these and lower doses (2.5 mg/kg and 10 mg/kg) the ratios in the striatum of levels of acetylcholine to levels of dopamine were significantly increased. Only at the highest dose did morphine increase the levels of dopamine in the striatum and of acetylcholine in the hippocampus. Morphine did not change the levels of dopamine in the striatum and of acetylcholine in the hippocampus. Morphine did not change the levels of norepinephrine in either the hypothalamus or cortex of the rat.

Acetylcholine↗
PubMed1969

Acetylcholine: release from neural tissue and identification by pyrolysis--gas chromatography.

Gas chromatographic analysis showed acetylcholine to be the only choline ester released from innervated longitudinal muscle of the guinea pigileum by electrical stimulation. The amount of acetylcholine measured by gas chromatography agreed almost exactly with that measured by bioassay. Denervated longitudinal muscle produced no acetylcholine, and treatment of the muscle with tetrodotoxin markedly reduced acetylcholine output. The method permits the recovery and quantitation of amounts of acetylcholine as low as 5 nanograms in 5 milliliters of tissue perfusates.

Acetylcholine↗