[Animal modeling] Detection of salsolinol N-methyltransferase activity in 6-hydroxydopa model rats

  Objective: To establish a rat model of Parkinson's disease (PD) with 6-hydroxydopamine (6-OHDA) and determine the activity of salsolinol N-methyltransferase (SNMT) in peripheral blood lymphocytes of rats.

  Methods: PD model was established by unilateral double point injection of 6-OHDA to damage rat striatum, and behavioral evaluation was carried out on the model; The crude enzyme solution of SNMT was extracted from the peripheral blood lymphocytes of model rats, and a method for the determination of the enzyme reaction product N-methyl salsolinol (NMSal) by high performance liquid chromatography tandem triple quadrupole mass spectrometry was established. The activity of SNMT was characterized by the production of NMSal.

  Results: A total of 7 of 18 rats injected with 6-OHDA were induced by apomorphine to show the rotation of the intact side (>7 r/min) in a constant direction. The success rate of modeling was 38.9%. A method for characterizing SNMT activity with high selectivity, sensitivity and repeatability based on multi reaction monitoring technology was established. In this method, the detection limit and quantification limit of NMSal were 49 pmol/L and 98 pmol/L, respectively, and the intra day and inter day precision were below 6.0%. The results showed that the SNMT activity in peripheral blood lymphocytes of rats in PD group was significantly different from that in sham operation group and normal group (P<0.01, n="5)," while="" there="" was="" no="" significant="" difference="" between="" normal="" group="" and="" sham="" operation="" p="">0.05, n=5).

  Conclusion: SNMT activity in peripheral blood lymphocytes may reflect the pathogenesis of PD and may be one of the diagnostic indicators.