Animal models of rheumatoid arthritis(RA)especially adjuvant arthritis(AA)in rats and collagen induced arthritis(CIA)in mice have much character similar to human RA in pathological mechanism,clinical representation and so on. The models are more ideal in investigating RA and selecting drugs of anti inflammation and immunity. To discuss the pathological mechanism and the relation between animal models of RA and clinic will be important not only to research RA in pathology,physiology,nervous endocrine immunity and so on,but also to find out safety and effective drugs of treatment RA. The articl summarizes several animal models of RA in establishment,pathological and clinical changes,inflammatory immune regulation and so on.

The effects of selenium-enriched yeast (Sey) on DTH in immunosuppressive mice have been investigated. It was found that Sey (30, 60, 90 mg?kg-l?d-1?6 d, ig) was able to antagonize lowered DTH by cyclophospha-mide (Cy); Meanwhile, the thymus and spleen weights were increased by Sey (30, or 60 mg?kg-1?d-1) in immunosuppressive mice. Sey also potentiated the lowered ConA and LPS-indu-ced proliferation of splenocytes in DTH mice at the doses of 30, 60, or 90 mg ?kg-1 and 60 or 90 mg?kg-1 respectively. These results suggested that Sey could enhance the functions of lymphocytes.

AIM To determine whether microinjection of ? amyloid peptide fragment 25～35 (A?25～35 ) into rat hippocampus induces the learning and memory dysfunction.METHODS Microinjection of A? 25～35 into hippocampus induced the rat learning and memory dysfunction. Step down test, Shuttle box test, and Morris water maze test were used to evaluate rat learning and memory function;The sections were stained with haematoxylin eosin (HE),the amyloid deposits were detected using Congo Red and silver.RESULTS The latency of A? 25～35 treated rats shortened,the stimulating time prolonged,and the numbers of errors increased in the step down test;Shuttle box test showed that A? 25～35 caused the latency and numbers of active escape reduction and the numbers of passive avoidance increase; Also in morris water maze, A?25 35 induced an impairment in rat spatial resolution; In A? 25～35 treated group, a significant decrease in the numbers of neurons in cortex and hippocampus,a massive glial reaction and neurophilic phenomenon were detected by HE staining; the positive vascular amyloidosis by Congo red and fibrils by Ag staining were also observed.CONCLUSION Microinjection of A? 25～35 into rat hippocampus may induce the learning and memory dysfunction and pathological changes which were similar to that found in Alzheimers disease (AD) brain.

AIM To study the analgesic effects of melatonin (MT) and related mechanisms. METHODS The threshold was measured by hot plate test.? endorphine (? EP) was determined by radioimmunoassay (RIA). RESULTS MT (40～160 mg?kg -1 , ip) had significant dose and time dependent analgesic effects in hot plate test. The analgesia was also induced by injection (icv) of MT (0 25 mg?kg -1 ). The day night rhythm of pain threshold was not observed in 7 d after pinealectomy, but it appeared in sham operated rats.? EP content of rat brain measured by RIA indicated that the level of ? EP in hypothalamus and pituitary decreased significantly 1 h after ip MT(100 mg?kg -1 ). The analgesic effect of MT was attenuated by pretreatment of reserpine (3 mg?kg -1 ip) or ? receptor blocker phentolamine (100 mg?kg -1 , sc). CaCl 2 (230 mg?kg -1 ) antagonized the analgesic effect of MT, and EGTA and verapamil significantly enhanced the analgesia of MT in the same situation. CONCLUSION MT has significant analgesic action which may be related to opiate system, adrenergic system, and Ca 2+ content.

AIM: To study the exciting effects of ethanol extract of capitate phrynium (Phrynium Capitatum Willd) stem and leaf on the uterine smooth muscle of rat,mice,guinea pig and rabbit pretreated by diethylstilbestrol. METHODS: Conventional method was adopted to prepare animal uterine specimens both in vivo and in vitro. Different doses of the extract were given to the specimens and recorded their tensility, frequency and activity of contraction with the help of BL-420 biological experimental system. IC_(50) of the extract was calculated, with oxytocin as standard comparison. RESULTS: 95% ethanol extract and 50% ethanol extract of capitate phrynium and leaf had obviously stimulating action on the uterine smooth muscle of rat, mice, guinea pig and rabbit in a dose-dependent manner in vitro, whichinclude accelerating contraction frequency, raising tension (P<0.05, P<0.01). In addition, 50% ethanol extract also had a significant stimulating action on uterine smooth muscle of rabbit in vivo(P< 0.01). CONCLUSION: Ethanol extracts of capitate phrynium have an effect on rodent uterine. Smooth muscle indicates that clinical application of Chinese practitioner used to treat the dysfunctional uterine bleeding proves to be effective.

AIMTo investigate the effects of the recombina nt human endostatin on adjuvant arthritis (AA) in rats and its mechanisms. METHODSThe model of rat AA was induced by injection of intradermal CFA. ConA and LPS induce d splencytes proliferation was examined by MTT asssy and the activities of inter leukin-1 (IL-1) and IL-2 were measured by the method of thymocytes prolifera tion. Synoviocytes were dispersed with incubation of collagenase and trypsin, an d IL-1, TNF production of synoviocytes was estimated with radio-immunity assay . RESULTSThe secondary inflammation of AA rats appeared on the 1 0th day after injection of CFA. The therapeutic administration of endostatin (0 1, 0 5, 2 5 mg?kg -1 ?d -1 , sc, ?7 d) was given at that time(d 10). It was found that endostatin significantly inhibited the secondary paw swel ling. The increased ConA-induced splenic lymphocyte proliferation reaction and the activated IL-1 and IL-2 activity of AA rats was reversed by the treatment with endostatin. Meanwhile,IL-1 produced by PM? was increased. Endostatin inh ibited IL-1 production from PM? and IL-1 and reduced TNF level of Synoviocyte s in AA rats. CONCLUSIONThe recombinant human endostatin has the rapeutical effect on AA rats, its mechanisms is related to its immunoregulative function.

AIM: To study the exciting effects of ethanol extract of capitate phrynium(Phrynium Capitatum Willd) stem and leaf on the uterine smooth muscle of rat、mice、guinea pig and rabbit pretreated by diethylstilbestrol. METHODS: Conventional method was adopted to prepare animal uterine specimens both in vivo and in vitro.Different doses of the extract were given to the specimens and recorded their tensility,frequency and activity of contraction with the help of BL-420 biological experimental system.IC_50 of the extract was calculated,with oxytocin as standard comparison. RESULTS: 95% ethanol extract and 50% ethanol extract of capitate phrynium and leaf had obviously stimulating action on the uterine smooth muscle of rat,mice,guinea pig and rabbit in a dose-dependent manner in vitro,which include accelerating contraction frequency,raising tension(P

AIM To investigate whether melatonin improve the learning and memory dysfunction in the amnesic rats induced by amyloid ? peptide 25～35 (A? 25～35 ) via cholinergic nervous system or not.Methods The amnesic model in adult rats was induced by injection of A? 25～35 into hippocampus; Morris water maze was used to determine the effects of A? 25～35 and melatonin on the learning and memory. The activity of the choline acetyltransferase and acetylcholinesterase were determined by immunohistochemistry and spectrophotometry respectively. RESULTS Injection of A? 25～35 20 ?ginto the adult rats hippocampus induced learning and memory dysfunction, and a decrease in the number of ChAT immunoreactive neurons in hippocampus. Melatonin (0 1, 1, and 10 mg?kg -1 , ig?10 d) improved the A? 25～35 treated rats cognitive function and increased the number of ChAT immunoreactive neurons in hippocampus. CONCLUSION Improvement of the cholinergic dysfunction by melatonin in adult rats induced by amyloid ? peptide 25～35 may be via cholinergic nervous system.

AIM To study immunomodulation and antitumor activity of paeonol. METHODS Paeonol was administered singlely to HepA bearing mice. 14 d later, the inhibition of tumor weight were observed. IL-2 and TNF-? content in serum, IL-2 secretion by splencytes, TNF-? production by PM? were measured by RIA. RESULTS Paeonol possess markedly inhibitory activity on the growth of HepA tumor in mice, and IL-2 and TNF-? were induced signficantly. CONCLUSION Paeonol has the effects of antitumor. This effect may be derived from inducing IL-2 and TNF-? production.

AIM To determine the concentration of paeonol in the bulk drug and injection, a method of reversed-phase high performance liquid chromatography (RP-HPLC) was developed. METHODS Lichrospher C_ 18 column(4.6 mm?250 mm, 5 ?m)was used with methanol-acetonitrile-water(30∶40∶30)as mobile phase at a flow rate of 0.8 ml?min -1 . 20 ?l of sample was injected into the C_ 18 column where the temperature was 25℃. The detection wavelength was 274 nm. RESULTS The linear regression equation for paeonol was = 3 772.525 8 X- 0.747 4 (r = 1.000 0, n =5) under the linearity range from 0.02 mg?L -1 to 25.60 mg?L -1 . The average recovery was 99.87%. The relative standard deviations of the intra-day and inter-day were less than 4%. CONCLUSION The method is simple and rapid, which may be used for the determination of paeonol and its preparation for different purpose.