| Selenium(Se) presented significant impact on immunity and reproduction of animals. Research on its regulation to local cytokines secreted in pregnant uterus is of great importance on its regulation mechanism and application to animal reproduction. This study included following five experiments in order to explore the immunological mechanism of its regulation to goat pregnancy at celular and moleacular level.In Experiment 1 sixty-four adult female rabbits were randomly divided into three experimental groups and a control group. 16 rabbits each. Rabbits in experimental groups were intramuscularly injected with sodium selenite solution respectively at the doses of 0.3. 0.4 and 0.5 mg(Se) ?kg"1 (body weight) and control group with physiological saline (1.0 mL ?kg"'). Each group was treated weekly for eight weeks and then the rabbits in experimental groups acted as subacutely poinsoned model rabbits. Blood samples before treatment and 2. 4, 6 and 8 weeks after treatments were collected from heart or vein and analyzed for selenium content. Female adults in all groups were mated naturally with normal males 8 weeks after treatment. Statistics showed that blood selenium concentration in each experimental group was significantly higher than that of control group (P<0.05 or P<0.01). that the concentration of blood selenium could be clinidally used to diagnose the selenium poisoning, that the toxicity of selenium could cause decrease of oestrus rate, pregnancy rate and the number of fetuses of the births, all proving that the selenious reagent and its doses in this study could result in reproductive barrier in rabbit.In Experinent 2 the peripheral blood mononuclear cells (PBMC) were aseptically isolated from goats not treated by selenium and cultured in vitro in media containing sodium selenite respectively at the levels of 4, 8. 12 and 16 u g ?mL"'. and then their invitro activation and IL-2 levels were tested. The results showed that 8~12 u g ?mL"1 sodium selenite could significantly (P<0.05,orP<0.01) activate goat PBMC in vitro in a dose-dependent manner, that 4 and 16 u g ?mL"' sodium selenite also activated goat PBMC but not significantly(.P>0.05) in comparison to control group (0 u g ?mL"' sodium selenite). The in vitro secretion of IL-2 by goat PBMC was significantly (P<0.01 ) promoted by 8~12 u g -mL"1 sodium selenite but not significantly by 4 and 16 u g ?mL"1 sodium selenite. all indicating that sodium selenite within certain range of doses could dose-dependently stimulate the secretion of IL-2 by goat PBMC.In Experiment 3 totally 12 female adult goats were randomly arranged in experimental goupes A, B and C and central group D, 3 goats each, in order to analyse the effect of Se orally intaken on the activation of goat PBMC. Goats in group A, B and C orally took sodium selenite solution at doses of 0.3, 0.5 and 0.7 mg(Se)-kg~' respectively and those in control group each orally took 1.0 mL ?kg"1 distilled water once a week for three times. Blood samples were collected from goats before all treatments and 24 h after each treatment and tested for selenium. PBMC were aseptically isolated from goat blood before all treatments and one week after each treatment to conduct in vitro activation, with purified phytohemagglutinin(PHA-P) as activator. The results showed that PBMC from goats 2 weeks after oral administration with 0.7 mg(Se) ?kg"1 or 3 weeks after oral administration with 0.5 and 0.7 mg (Se) ?kg"1 could be significantly (P <0.05~) stimulated by PHA-P, implying that oral administration with a certain amount of Se could sensitize the responseof goat immunocytes to antigen.Experiment 4 is designed to test the in vitro actvation of endometrial lymphocytes(EML) by Se. EML were aseptically isolated from pregnant goat, in vitro cultuled inmedia respectively containing 4, 8, 12, 16 u g ?mL"1 of sodium selenite and their in vitroactivation and IL-2, IL-4, TGF- P , and TGF- P 2 secretion were assayed. The resultsshowed that 8?6 u g ?mL"1 sodium selenite significantly activated goat EML in a... |
