Synthesis of O-[11C]Acetyl CoA, O-[11C]Acetyl-L-carnitine, and L-[11C]carnitine labelled in specific positions, applied in PET studies on rhesus monkey.

The syntheses of L-carnitine, O-acetyl CoA, and O-acetyl-L-carnitine labelled with 11C at the 1- or 2-position of the acetyl group or the N-methyl position of carnitine, using the enzymes acetyl CoA synthetase and carnitine acetyltransferase, are described. With a total synthesis time of 45 min, O-[1-11C]acetyl CoA and O-[2[11C]acetyl CoA was obtained in 60-70% decay-corrected radiochemical yield, and O-[1-11C]acetyl-L-carnitine and O-[2-11C] acetyl-L-carnitine in 70-80% yield, based on [1-11C]acetate or [2-11C]acetate, respectively. By an N-methylation reaction with [11C]methyl iodide, L-[methyl-11C]carnitine was obtained within 30 min, and O-acetyl-L-[methyl-11C]carnitine within 40 min, giving a decay-corrected radiochemical yield of 60% and 40-50%, respectively, based on [11C]methyl iodide. Initial data of the kinetics of the different 11C-labelled L-carnitine and acetyl-L-carnitines in renal cortex of anaesthetized monkey (Macaca mulatta) are presented.

[1]  L. Feinendegen,et al.  Synthesis of carbon‐11 labelled (R)‐carnitine , 1991 .

[2]  J. Williamson.  Effects of insulin and starvation on the metabolism of acetate and pyruvate by the perfused rat heart. , 1964, The Biochemical journal.

[3]  B. Långström,et al.  The preparation of 11C-methyl iodide and its use in the synthesis of 11C-methyl-L-methionine. , 1976, The International journal of applied radiation and isotopes.

[4]  H. Misaki,et al.  Acylcarnitine deficiency in chronic fatigue syndrome. , 1994, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America.

[5]  C. De Simone,et al.  Immunological responses in patients with tuberculosis and in vivo effects of acetyl-L-carnitine oral administration , 1993, Mediators of inflammation.

[6]  S. Valind,et al.  Synthesis of fatty acids specifically labelled with 11C in various positions, including 2H substitution, for in vivo studies of myocardium using PET. , 1994, Nuclear medicine and biology.

[7]  B. Långström,et al.  Uptake and utilization of [beta-11C] 5-hydroxytryptophan in human brain studied by positron emission tomography , 1992, Psychiatry Research: Neuroimaging.

[8]  M. Alberoni,et al.  Long‐term acetyl‐L‐carnitine treatment in Alzheimer's disease , 1991, Neurology.

[9]  G. Antoni,et al.  Synthesis of L- and D-[methyl-11C]methionine. , 1987, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[10]  E. Arrigoni,et al.  Effects of acetyl-l-carnitine on the survival of adult rat sensory neurons in primary cultures , 1992, International Journal of Developmental Neuroscience.

[11]  Yasuyoshi Watanabe,et al.  Enzymatic Synthesis of Carboxy-11C-Labelled L-Tyrosine, L-DOPA, L-Tryptophan and 5-Hydroxy-L-tryptophan. , 1990 .

[12]  B. Långström,et al.  The 11C/14C kinetic isotope effect method. The 11C/14C kinetic isotope effect in the SN2 reaction of N,N‐dimethyl‐p‐toluidine with labelled methyl iodide , 1991 .

[13]  M. Fratelli,et al.  Activation of apoptosis by serum deprivation in a teratocarcinoma cell line: inhibition by L-acetylcarnitine. , 1993, Experimental cell research.

[14]  V. Pike,et al.  Preparation of [1-11C]acetate--an agent for the study of myocardial metabolism by positron emission tomography. , 1982, The International journal of applied radiation and isotopes.

[15]  S. Osman,et al.  Propionyl-L-carnitine: labelling in the N-methyl position with carbon-11 and pharmacokinetic studies in rats. , 1995, Nuclear medicine and biology.

[16]  L. Rampello,et al.  Trophic action of acetyl-L-carnitine in neuronal cultures. , 1992, Acta neurologica.

[17]  H. Lundqvist,et al.  β+-Selective radiodetector for capillary electrophoresis , 1993 .

[18]  B. Långström,et al.  Synthesis of [1-11C], [2-11C], [1-11C](2H3) and [2-11C](2H3)acetate for in vivo studies of myocardium using PET. , 1994, Nuclear medicine and biology.

[19]  M. S. Murthy,et al.  Carnitine-acylcarnitine translocase deficiency: implications in human pathology. , 1994, Biochimica et biophysica acta.