title: Determination method of 1-methyl-1,2,3, 4-tetrahydroisoquinoline, an endogenous parkinsonism-preventing substance, by radioimmunoassay.
abstract: To develop a sensitive and simple assay method for 1-methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ), an endogenous parkinsonism-preventing substance, we designed two kinds of 1MeTIQ-bovine serum albumin (BSA) conjugates to recognize the methyl group at the 1 position of 1MeTIQ since this is the critical structural difference between 1MeTIQ and parkinsonism-inducing substances. These hapten antigens were synthesized from 1MeTIQ analogues and BSA. A specific antiserum against 1MeTIQ was obtained from a rabbit immunized with one of the hapten antigens. To utilize this antiserum for radioimmunoassay, detailed studies were carried out to establish optimum conditions. The antiserum recognized 1MeTIQ and showed little cross-reactivity with endogenous 1MeTIQ analogues and proteins. It was confirmed to be suitable for radioimmunoassay, and a standard curve was prepared in the range of 0.5 to 100 pmol of 1MeTIQ. This method was sensitive enough to measure endogenous 1MeTIQ in rat brain. This method should be applicable for evaluation of the progression or prognosis of Parkinson's disease (PD).
authors.affiliation: Institute of Pharmaceutical Sciences, Hiroshima University School of Medicine, Japan.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Okuda
authors.forename: Yaichiro
authors.initials: Y
authors.lastname: Kotake
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ohta
mesh_terms: D000818:Animals; D000917:Antibody Formation; D015153:Blotting, Western; D001923:Brain Chemistry; D018492:Dopamine Antagonists / Q000032:analysis* / Q000276:immunology; D005260:Female; D006241:Haptens / Q000737:chemistry; D007106:Immune Sera; D007546:Isoquinolines / Q000032:analysis* / Q000276:immunology; D008297:Male; D020734:Parkinsonian Disorders / Q000517:prevention & control; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D012680:Sensitivity and Specificity; D012710:Serum Albumin, Bovine / Q000737:chemistry; D044005:Tetrahydroisoquinolines; D013997:Time Factors
chemical_list: D018492:Dopamine Antagonists; D006241:Haptens; D007106:Immune Sera; D007546:Isoquinolines; D044005:Tetrahydroisoquinolines; D012710:Serum Albumin, Bovine; C050386:1-methyl-1,2,3,4-tetrahydroisoquinoline