V Mihova, M Mangarova, D Zhelyazkov
Keywords: amphetamine-free fatty acids-selective lipolysis-dose-and time-dependence-rats Amphetamine effect on lipid metabolism is an object of numerous investigations conceived mainly by its manifested anorexigenic influence and sti­ mulating action on mental and physical working capacity. Amphetamine increa­ ses free fatty acids (FFA) in plasma which is an evidence for the influence of this drug on lipolytic processes (5, 7, 8, 10). It is suggested that amphetamine lipolytic effects are
more » ... c effects are related to noradrenalin liberation from adrenergic neurons, to an increased adrenalin secretion from the adrenal medulla or that they are of central origin (9). There are scanty investigations of details of amphetamine lipolytic action. According to Bizzi et al. (5) amphetamine does not induce FFA concentration changes in the adipose tissue. No data about its action on single lipid classes (triglycerides, cholesterol esters, phospholipids) as well as about its influence on individual plasma FFA liberation are available. Our earlier studies in man showed an outlined selectivity of amphetamine lipolytic action related to arachi-donic acid liberation (2). The present investigation is directed towards further characterization of amphetamine lipolytic effect. Dose-and time-dependence of this effect is examined concerning the main plasma FFA: C 14:0 (myristic acid), C 16:0 (palmitic acid), QL6:I (palmitoleic acid), C 18:0 (stearic acid), C 18:1 (oleic acid), C 18:2 (linolic aci d), С 2 о:з (eicosotrienic acid) and C 20:4 (arachidonic acid). Material and methods F The study covered 94 white male rats with 150-170 g b. w. Amphetamine was applied at doses of 5, 10 and 20 mg/kg b. w. intraperitoneal^. Effect was controlled on the 30 th min with all the doses used but also on the 15 th and 60 th min after drug administration with the dose of 10 mg/kg b. w. Blood for examina­ tion was taken by means of sublingual vein incision. Control animals given sa­ line injections were parallelly killed with corresponding doses and time-inter­ vals of experimental ones. Blood plasma was extracted according to the method of Folsh et al. (6). Lipid extract obtained was processed by using of thin-layer chromatography in the system hexane:ether:acetic acid (3). FFA were methylized by diazomethan syn­ thesized in our laboratory. Methyl esters of the fatty acids were analysed by means of gas-liquid chromatography (gas chromatograph «Chrom 4»).