3D-QSAR studies on a series of dihydroorotate dehydrogenase inhibitors: analogues of the active metabolite of leflunomide.

The active metabolite of the novel immunosuppressive agent leflunomide has been shown to inhibit the enzyme dihydroorotate dehydrogenase (DHODH). This enzyme catalyzes the fourth step in de novo pyrimidine biosynthesis. Self-organizing molecular field analysis (SOMFA), a simple three-dimensional quantitative structure-activity relationship (3D-QSAR) method is used to study the correlation between the molecular properties and the biological activities of a series of analogues of the active metabolite.

[Effects of paroxetine on protein kinase PKA, PKC and CaMKII activity in different brain regions in a rat depression model].

Objective: To evaluate the effects of paroxetine on protein kinase PKA, PKC and CaMKII activities in different brain regions in a rat model of depression.

Methods: Thirty-six adult male SD rats were randomized into 6 groups, including one control group (I) and 5 groups of depression model established by forcing the rats to swim for 4 weeks. The 5 depression groups received no treatment (II) or were treated with paroxetine at a single dose (III), for a week (IV), 2 weeks (V) or 4 weeks (VI).

[Determination of clonidine in rabbit plasma by HPLC-MS].

Aim: To determine clonidine in rabbit plasma by LC-MS.

Methods: The LC-MS system consisted of Waters Alliance 2790 HPLC and Micromass ZQ-4000 MS. The HPLC was performed by using XTerra C18 (150 mm x 2.