The mechanism of hypotensive effect of siiybin was studied in anesthetized cats and rats. The results show that the hypotensive action caused by siiybin is not central in origin, and not related to the effect of autonomic nervous system and the release of histamine and prostagiandin, but is mainly due to vasodilation.

Antigen challenge of sensitized isolated guinea-pig mesentery perfused under constant pressure resulted in a significant flow reduction which was induced by the release of leukotrienes bioassayed on guinea-pig ileum. 3 min after challenge, the mescnteric perfusion rate dropped to a minimum of 32?12% ( P

Objective: To establish an experimental model of atherosclerosis in rats and to study the atherosclerotic lesions in the aorta,heart and liver.Methods: The rats in experimental groups were injected with a single dose of vitamin D (600 000 IU/kg) and loaded with high fat diet;control group was given saline and basic food.The pathological changes were observed in the aorta,heart and liver after 2,4,6 weeks.The scores were evaluated according to the pathological degrees.Results: No changes were observed after 2 weeks,but after 4 weeks atheroslerotic plaques were seen in the aorta and the score of the lesions were 0.50?0.39; a little lipid were found in coronary arteries;deposition of lipid was seen in the myocardium; many positive red pellets were found in the plasma of cells in the liver.After 6 weeks,more atheroslerotic plaques were observed in the aorta,and atheroslerotic plaques in coronary arteries were formed (pathological score 1.12?0.48); abundant positive red pellets were found in the plasma of the cardiac myocyte.The pathological changes occurred in rats were very similar to that of man.Conclusion: The experimental model of atherosclerosis in rat may be conveniently established by injection of vitamin D with loading of high fat diet,which can be used for the pathological and pharmacological study of atherosclerosis.

The effects of imperatorin (Imp) and iso-imperatorin(Isi) on tumor necrosis factor (TNF) release from mouse peritoneal macrophages were investigated. It was found that Imp and lsi significantly inhibited TNF release from mouse peritoneal macrophages. At the concentration of 10-6～10-4 mol?L-1, the inhibitory effects were presented by Imp and Isi in a dose dependent manner. At 10-4 mol/L TNF release was entirely inhibited by each drug.

This study is to investigate the protein and mRNA expressions of pro-inflammatory and anti-inflammatory cytokines in U937 foam cells and effects of Ginkgo biloba extract (GbE) on the cytokines.U937 cells were cultured with different concentrations of GbE (0.1,1,and 10 μg·L-1),and stimulated by 100 mg·L-1 oxidized low density lipoprotein (ox-LDL) for 24 h.The expressions of interleukin-1β (IL-1β),tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) in culture solution were detected by enzyme-linked immunosorbant assay (ELISA) and reverse transcriptase polymerase chain reaction (RT-PCR).The results showed that incubated with 100 mg·L-1 ox-LDL for 24 h,the U937 cells became foam cells,the protein or mRNA expressions of IL-1β,TNF-α,IL-10,and its receptor IL-10R in U937 foam cells were higher markedly than those in normal U937 cells.When the cells were pretreated with GbE (0.1,1,and 10 μg·L-1),the increases of IL-1β and TNF-α in U937 foam cells were remarkably inhibited,but IL-10 expression increased greatly.Especially when cells were pretreated with 10 μg·L-1 GbE,the protein and mRNA expressions of IL-1β and TNF-α were markedly lower than those in U937 foam cells.The protein expression of IL-10 and mRNA expressions of IL-10 and its receptor IL-10R were markedly higher than those in U937 foam cells.GbE inhibited production of pro-inflammatory cytokines IL-1β and TNF-α,but up-regulated the production of anti-inflammatory cytokine IL-10 and its receptor IL-10R in U937 foam cells,which might be related with its anti-atherosclerotic actions.

Specific receptors for leukotriene C4 LTC4 have been identified on intact smooth muscle cells derived from bovine cerebral microvasculatures. Specific pHJLTC4, binding at a fixed input at 25 ℃ was rapid , reaching the maximum at 20min With incremental inputs of radioligand and a constant cell number, specific [3H]LTC4 binding reached a plateau indicative of a saturable binding site. Analysis of Scatchard plots demonstrated a single high affinity binding site with a dissociation constant (Kd) of 2.01?0.4 nmol/L and Bmax = 156.6?13.1 fmol/106 cells. The specific [3H]LTC4 binding could be inhibited by unlabted LTC4, LTD4 and FPL-55712 with an inhibitory rate of 96.9%, 73.9% and 44.9% at 10-5 mol/L, respectively.

The release of platelet activating factor (PAF) induced 14C-arachidonic acid (14C-AA) in the bovine cerebral microvascular endothdial cells (CMEC) and arterior cerebral artery smooth muscle cells (ACASMC) and the antagonism of SZ-1 are described. The results showed that 14C-AA incorporated into the cells rapidly and PAF 0.1-20?mol/L dose-dependently stimulated the AA release significantly. It indicated that the action of PAF on the cerebrovascular system was associated with the stimulation of AA release. SZ-1 0.2-20?nol/L dose-dependently inhibited the PAF induced AA release in CMBC and ACASMC, and PAF induced aggregation of washed rabbit platelets, but did not inhibited ADP or AA induced aggregation of platelet-rich plasma(PRP), and PAF production in CMEC, indicating the specific antagonism of SZ-1 on PAF receptor.

OBJECTIVE: To evaluate the effects of madecassoside (MC) on the depression behavior of mice and the activities of monoamine oxidase (MAO) in different rat brain regions. METHODS: Imipramine as the positive contrast medicine, effects of MC on the depression behavior of mice were observed by forced swimming test and reserpine antagonist test. Moclobemide and pargyline as the positive controlled medicines, the activities of monoamine oxidase-A (MAO-A) and monoamine oxidase-B (MAO-B) in different rat brain regions were determined after intragastric administration of MC in 3 different dosages for 3 days or 21 days. RESULTS: (1) The low, middle and high dosages of MC (i.g.) significantly reduced the immobility time of mice in forced swimming test (P<0.05). (2) MC in dosages of 10 mg/kg and 20 mg/kg prevented the lowering of temperature induced by reserpine (P<0.05), while 40 mg/kg had no significant effects on it (P>0.05). (3) With acute administration (3 days), the low, middle and high dosagey of MC (i.g.) significantly inhibited the activity of MAO-A in hippocampus (P<0.01), and the high dosage significantly inhibited the activity of MAO-A in hypothalamus (P<0.01), while the 3 dosages had no significant effects on the activity of MAO-A in cortex (P>0.05). With chronic administration (21 days), MC in 3 dosages had no significant effects on the activities of MAO-A in cortex and hypothalamus (P>0.05), and the high dosage (40 mg/kg) significantly enhanced the activity of MAO-A in hippocampus (P<0.01). (4) With acute administration, MC in dosages of 10 mg/kg and 20 mg/kg significantly inhibited the activity of MAO-B in cortex (P>0.05), and MC in dosage of 10 mg/kg significantly inhibited the activity of MAO-B in hypothalamus (P<0.05), and MC in dosage of 20 mg/kg significantly enhanced the activity of MAO-B in hippocampus (P<0.01). With chronic administration, MC of 3 dosages produced no significant effects on the activities of MAO-B in 3 different rat brain regions (P>0.05). CONCLUSION: These results support the idea that MC produces antidepressant effects through MAO inhibition in rat brain, which seems stronger with acute administration than chronic administration, while its mechanism remains to be further studied.