Effect of traditional Chinese medicine Muniziqi on gonad axis in rats with chronic stress premature ovarian failure

AIM: To investigate the effects of traditional Chinese medicine Muniziqi on chronic premature ovarian failure (POF) by observing the histomorphological changes of pituitary, hypothalamus and ovary in rats with chronic POF. METHODS: Mature Sprague-Dawley rats (female, n=90) were randomly divided into normal group (n=10), and stress model group (n=80). After the model was established, the rats with POF were screened. The model rats were divided into POF group, and POF with high-, medium- and low-dose Muniziqi groups. HE staining and Masson staining were used. The morphological changes of pituitary, hypothalamic and ovarian tissues were observed, and the ovarian and uterus indexes were calculated. The serum levels of estradiol (E₂), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in the rats were measured by ELISA. RESULTS: The traditional Chinese medicine Muniziqi had certain effects on the morphological changes and hormone levels of pituitary, hypothalamic and ovarian tissues in the rats with chronic POF. Compared with POF group, each drug intervention group had different degrees of improvement. Compared with normal group, the E₂ level in POF group was significantly decreased (P<0.05), and the levels of LH and FSH were significantly increased (P<0.05). CONCLUSION: Chronic stress results in the occurrence of POF. The traditional Chinese medicine Muniqizi has the effects on prevention and treatment of POF and improvement of histomorphological changes and hormone levels of the gonaol axis.     

Effects of weightlessness simulated by tail-ventrofixation on reproductive functions in female rats

AIM: To investigate the effects of weightlessness simulated by tail-ventrofixation on reproductive functions in female rats and the underlying mechanism, and to provide some clues to health protection for the space explorers.METHODS: To mimic the weightless state, the rat model of tail-ventrofixation was set up. Seventy-two female Wistar rats were randomly divided into 6 groups: 7-day,14-day and 21-day tail-ventrofixation groups and the corresponding 3 control groups without tail-ventrofixation. The levels of estradiol (E₂), follicle stimulating hormone (FSH) and luteinizing hormone (LH) in the serum were detected by ELISA. The morphological characters of the ovary were examined under microscope with HE staining. The character of senescence was checked by senescence-specific lipofuscin staining in situ. The RNA of the ovary was extracted to detect the mRNA expression levels of telomerase reverse transeriptase(TERT),p53, p27,p21 and P16 by qRT-PCR. The protein levels except TERT were also detected by immunohistochemistry. The male Wistar rats cohabited with the female ones to test the quantity and the survival rate of their offspring.RESULTS: Compared with the corresponding control groups, the serum level of E₂ decreased in tail-ventrofixation groups (P<0.05). However, the levels of FSH and LH increased (P<0.05). At the same time, the number of ovarian follicle in tail-ventrofixation groups reduced compared with the corresponding control groups, and the ovary cells showed the characteristics of senescence. The expression of TERT was inhibited in tail-ventrofixation groups compared with the corresponding control groups not only in the level of mRNA but also of the proteins (P<0.05). Meanwhile, the expression of p53, p27 and p16 increased (P<0.05). Both the number and the survival rate of offspring rats decreased in tail-ventrofixation groups as compared with the corresponding control groups (P<0.01).CONCLUSION: The state of simulated weightlessness results in decreased reproductive functions in female rats. Simulated weightlessness induces cell senescence and endocrine dysfunction of hypothalamus-pituitary-ovarian axis.     

Effects of superovulation on histological changes and functions of reproductive endocrine in rat ovary

AIM: To study the effects of superovulation on the histological changes and reproductive endocrinic functions of rat ovary.METHODS: Thirty female SD rats were randomly divided into 3 groups: the rats in experimental group A were treated with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (HCG) for 6 times; the rats in experimental group B were treated with normal saline for 3 times, subsequently stimulated with the same reagents in experimental group A for 3 times; the control rats were treated with normal saline for 6 times. Half of the rats were killed on the 15th day of the experiment, and the others were killed at the end of the experiment. The ovarian morphology and follicle number were observed. The serum estrodiol-2 (E₂), follicle stimulating hormone (FSH), luteinizing hormone (LH) and FSH/LH levels were determined by radioimmunoassay.RESULTS: The number of primordial follicles and primary follicles in the two experimental groups were significantly lower than those in control group (P<0.05). However, no significant difference of the serum basal hormone level among the 3 groups was observed (P>0.05).CONCLUSION: Superovulation can restrain the development of the follicles in a frequency-dependent manner.     

Effects of astragaloside on the levels of sex hormone and oxidative stress injury in rats with polycystic ovary syndrome

AIM To investigate the effects of astragaloside on the levels of sex hormone and oxidative stress in rats with polycystic ovary syndrome （PCOS）. METHODS Female SD rats （n=60） were randomly divided into normal control group, model group, Diane-35 （0.339 2 mg/kg） group, low dose astragaloside （12.5 mg/kg） group and high dose astragaloside （50 mg/kg） group, with 12 rats in each group. The PCOS model was induced by letrozole （1 mg/kg）, which was administered by gavage once a day for 3 weeks. After administration, the estrus cycle of the rats was observed by vaginal smear, and the ovarian index was calculated. HE staining was used to observe the histopathological changes of the ovaries. Serum levels of the sex hormones testosterone （T）, estradiol （E₂）, luteinizing hormone （LH） and follicle-stimulating hormone （FSH） were measured by ELISA. The levels of superoxide dismutase （SOD）, malondialdehyde （MDA） and glutathione peroxidase （GSH-Px） in serum and ovarian tissue were detected by colorimetry, and the protein levels of steroidogenetic acute regulatory protein （StAR） and apoptosis-related proteins cleaved caspase-3, Bax and Bcl-2 in ovarian tissue were detected by Western blot. RESULT Compared with control group, the oestrous cycle of the rats in model group was disorder, and the ovarian index was increased, ovary was polycystic. The serum levels of T, LH and MDAwere significantly increased （P<0.05）, while the contents of E2, FSH and the activities of GSH-Px and SOD were significantly decreased （P<0.05）. The levels of MDA, StAR, cleaved caspase-3 and Bax proteins in ovarian tissue were significantly up-regulated （P<0.05）. GSH-Px and SOD activities and Bcl-2 protein levels were significantly down-regulated （P<0.05）. CONCLUSION Astragalosideeffectively balances the levels of sex hormone in PCOS rats and relieves the oxidative stress injury, the mechanism may be related to the inhibition of StAR expression.     

Estradiol promotes growth of decidua derived mesenchymal stem cells by inhibiting miR-16 via estrogen receptor α

AIM: To study the effect of estradiol (E₂) on the viability of mesenchymal stem cells (MSCs) derived from the decidua of the placenta by regulating the expression of microRNA-16 (miR-16). METHODS: The concentration of E₂ in the peripheral blood of normal pregnant women and the patients with severe preeclampsia (PE) was measured. The effects of E₂ at different concentrations on the viability of MSCs were analyzed. The effect of E₂ at different concentrations on the expression of miR-16 in the MSCs was detected, and which estrogen receptor (ER) mediated the regulatory effect of E₂ on miR-16 expression was determined. RESULTS: The concentration of E₂ in peripheral blood of the patients with severe PE was significantly decreased (P<0.01). After treatment with E₂ at 5, 10 and 100 nmol/L for 48 h, the viability of MSCs was increased (P<0.05). The expression level of miR-16 was down-regulated in the MSCs treated with E₂ at 5, 10 and 100 nmol/L for 12 h. After treatment with E₂ at 10 nmol/L for different time (0 h, 3 h, 6 h, 12 h and 24 h), the expression level of miR-16 in the MSCs showed a clear time-dependent downward trend. E₂ significantly promoted the viability of MSCs, and the cell viability was significantly reversed after miR-16 pretreatment. Pretreatment with estrogen receptor antagonists ICI 182780 and tamoxifen for 6 h attenuated the inhibitory effect of E₂ on miR-16 expression. Only ERα agonist propyl pyrazole triol significantly inhibited the expression of miR-16 in MSCs but ERβ agonist diarylpropionitrile did not. CONCLUSION: E₂ promotes the growth of decidua-derived MSCs by inhibiting miR-16 via ERα.     

Role of caveolin-1 on down-regulation of LPS-induced monocyte chemotactic protein 1 by 17β-estradiol in vascular smooth muscle cells

AIM: To elucidate the effect of caveolin-1 on the down-regulation of LPS-induced monocyte chemotactic protein 1 (MCP-1) by 17β-estradiol (E₂) in vascular smooth muscle cells (VSMCs).METHODS: The primary-cultured VSMCs were exposed to E₂ at concentrations of 10^-9-10^-6 mol/L. LPS-induced MCP-1 production was assayed by ELISA. The protein expression of caveolin-1 was determined by Western blotting and was silenced by β-methyl cyclodextrin(β-MCD) or caveolin-1 specific siRNA. RESULTS: LPS significantly enhanced MCP-1 production. E₂ at concentrations of 10^-9-10^-6 mol/L inhibited LPS-induced MCP-1 production. The use of caveolin-1 inhibitor β-MCD or silencing the protein expression of caveolin-1 by specific siRNA largely impaired LPS-enhanced MCP-1 production, while E₂ markedly inhibited caveolin-1 expression. CONCLUSION: Inhibition of LPS-induced MCP-1 production by E₂ is related to the suppression of caveolin-1.     

Therapeutic effects of modified Bushen Huoxue granules on ovariectomized osteoporosis rats

AIM: To observe the therapeutic effect of modified Bushen Huoxue granules (MBHG) on ovariectomized osteoporosis rats. METHODS: Female SD rats were randomly given sham operation (n=10) and ovariectomy, and then the model rats were further randomly divided into model group, MBHG treatment groups at doses of 200 mg/kg, 100 mg/kg and 50 mg/kg respectively, and positive control (estradiol valerate) group, with 10 rats in each group by intragastric administration for 12 weeks. The morphology, area, thickness, spacing and area percentage of trabecular bone in the rats were observed. The serum levels of calcium (Ca), phosphorus (P) and alkaline phosphatase (ALP) were mea-sured by automatic analyzer. Bone mineral density (BMD) was analyzed. Serum estradiol (E₂), osteocalcin (BGP), osteoprotegerin (OPG), receptor activator of nuclear factor-κB (RANK) and receptor activator of nuclear factor κB ligand (RANKL) levels were detected by ELISA. RESULTS: Compared with model group, trabecular bone significantly widened in all treatment groups with large number, and net-like structure restored partially. The thickness, area and area percentages of trabecular bone in treatments groups were higher than those in model group,and trabecular spacing was less than that in model group (P<0.05). The serum Ca, P, E₂ and OPG, and femoral BMD were significantly higher in treatment groups than those in model group, and the levels of ALP, BGP, RANK and RANKL were significantly lower than those in model group (P<0.01).CONCLUSION: MBHG has a significant therapeutic effect on ovariectomized osteoporosis rats. The mechanism may be related to the regulation of OPG and inhibition of RANKL secretion.     

Effects of drynaria total flavonoids on serum levels of leptin,interleukin 6, prostaglandin E2 and expression of bone β2-adrenergic receptor in ovariectomized osteoporosis rats

AIM: To investigate the effects of drynaria total flavonoids on serum levels of leptin (LEP), interleukin 6(IL-6), prostaglandin E₂(PGE₂) and the expression of bone β₂-adrenergic receptor (ADRB2) in a rat model of ovariectomized osteoporosis(OP). METHODS: The osteoporosis model was established by ovariectomy. Twelve weeks after modeling,bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry to verify successful modeling.Enzyme-linked immunosorbent assay was applied to detect the concentrations of LEP, IL-6 and PGE₂ in serum. The expression of ADRB2 was determined by immunohistochemical technique. RESULTS: Compared with sham group,BMD of the rats in model group significantly decreased in multiple regions 12 weeks after modeling(P<0.01). The serum levels of LEP, IL-6 and PGE₂ in model group were significantly higher than those in sham group(P<0.05). The levels of LEP, IL-6 and PGE₂ in drynaria total flavonoids group were significantly lower than those in model group(P<0.01). No significant difference of PGE₂ between these 2 groups was observed. The ADRB2 expression in sham group and treatment group was significantly different from that in model group, and no significant difference between sham group and treatment group was found. CONCLUSION: The serum levels of LEP, IL-6 and PGE₂ and the expression of bone ADRB2 increased in OP rats.Drynaria total flavonoids reduce the production of LEP, IL-6 and the expression of ADRB2, and suppress the bone absorption, which may be one of the mechanisms in treating OP.     

Effect of 17β-estradiol on the levels of plasma oxidized low density lipoprotein in ovariectomized rabbits

AIM: To observe the changes of plasma oxidized low density lipoprotein(oxLDL) levels of ovariectomized cholesterol-fed rabbits with or without 17β-estradiol(E₂) replacement therapy.METHODS: All rabbits were ovariectomized and fed standard chow supplemented with 1.5% cholesterol for 14 weeks. Two weeks after operation, the rabbits were randomly assigned to four groups. Three groups were treated with E₂ 1 mg, 2 mg, 4 mg respectively, the other group served as control. Serum superoxide dismutase (SOD) levels and plasma oxLDL levels were measured at 0, 3, 8, 12 weeks after hormone replacement therapy. The aortic atherosclerotic lesion areas were determined by computer. RESULTS: We found that there were striking increase of serum SOD levels ( P<0.05 ) and significant decrease in both the plasma oxLDL levels and the aortic atherosclerotic lesion areas ( P<0.01 respectively). Moreover, a positive correlation was found between plasma oxLDL levels and the areas of atherosclerotic plaque in all rabbits. CONCLUSIONS: Estrogen attenuates atherogenesis in cholesterol-fed ovariectomized rabbits. And this beneficial effect of E₂ may be duo to its lowering of plasma oxLDL level.     

EP2A promotes human CD34+ cell homing in vitro but not proliferation

AIM: To investigate the role of prostaglandin E₂ receptor 2 agonist (EP₂A) in proliferation and homing of human CD34⁺ cells. METHODS: Bone marrow fluid and peripheral blood containing stem cells were collected from healthy donors mobilized by granulocyte colony-stimulating factor in our department. Human CD34⁺ cells were isolated by the method of magnetic-activated cell sorting microbeads. Bone marrow mononuclear cells were isolated by Ficoll-Paque centrifugation, and the bone marrow mesenchymal stem cells (BMMSC) were cultured with L-DMEM. Human CD34⁺ cells and BMMSC were divided into 4 groups, and treated with PGE₂ (as positive control), DMSO (as negative control), EP₂A and EP₂A+prostaglandin E₂ receptor 2 antagonist (EP₂AA), respectively. After exposed to the reagents, human CD34⁺ cell viability was measured by CCK-8 assay, the number of colonies was evaluated by colony-formation assay, the cell cycle distribution was analyzed by flow cytometry, and the protein expression of survivin, β-catenin and CXC chemokine receptor 4 (CXCR4) was detrmined by Western blot. Moreover, the concentration of stromal cell-derived factor-1α (SDF-1α) in the BMMSC was detected by ELISA. RESULTS: The cell viability and the colony number of human CD34⁺ cells in EP₂A group were not higher than those in negative control group. Furthermore, the proportion of human CD34⁺ cells treated with EP₂A in G₂/M phase was not elevated compared with negative control group. The protein expression of survivin and β-catenin did not up-regulated in human CD34⁺ cells exposed to EP₂A, but the protein expression of CXCR4 in human CD34⁺ cells and the concentration of SDF-1α in BMMSC were elevated. CONCLUSION: EP₂A promotes human CD34⁺ cell homing in vitro but not proliferation.     

Role of central PGE2 on sympathetic excitation in chronic heart failure

AIM: To observe the effect of central prostaglandin E₂ (PGE₂) on sympathetic activation in chronic heart failure (CHF) and to explore the underlying mechanism. METHODS: Male SD rats were subjected to coronary artery ligation to induce heart failure (HF), and the intracerebroventricular infusion was performed by osmotic pump continuously. The rats in sham group and HF group were given artificial cerebrospinal fluid (0.25 μL/h). The rats in HF plus treatment group was given celecoxib (CLB; 20 mg/h). After 4 weeks, the levels of PGE₂ in cerebrospinal fluid (CSF), the sympathetic nerve excitability and cardiac function were measured, and the changes of corticotropin-hormone releasing hormone (CRH)-containing neurons activation and neurotransmitter contents in the hypothalamic paraventricular nucleus (PVN) were also determined. RESULTS: Compared with the sham-operated rats, the HF rats had raised level of PGE₂ in CSF, up-regulated renal sympathetic nerve activity and plasma norepinephrine, increased left ventricular end diastolic pressure, lung-to-body weight and right ventricular-to-body weight ratios, and decreased maximal increase and decreased rate of left ventricular pressure (P<0.05). In addition, the number of CRH positive neurons in PVN and the level of plasma adrenocorticotropic hormone were higher in HF rats than those in sham-operated rats (P<0.05). After administration of CLB into the lateral ventricle of HF rats, the contents of PGE₂ in CSF were significantly reduced, the number of activation CRH neurons in PVN was decreased, the excitability of sympathetic nerves was down-regulated and cardiac function was improved (P<0.05). Compared with the sham-operated rats, the content of glutamic acid in PVN of HF rats was increased, the content of γ-aminobutyric acid and the number of glutamate decarboxylase 67-positive neurons were decreased (P<0.05). After the CLB was given, the above indexes were reversed (P<0.05). CONCLUSION: These findings indicate that in CHF, the increased central PGE₂ may activate CRH-containing PVN neurons and contribute to the augmented sympathetic drive possibly by modulating the neurotransmitters within the PVN.     

Observation of estrous cycle in sexual maturation and ovariectomized female ICR mice

AIM: To observe the characteristics of estrous cycle of female ICR mice and ovariectomized mice that had reached sexual maturity stage. METHODS: ICR mice were randomly divided into 3 groups, normal group, sham operation group and ovariectomized group. After ovariectomy and sham operating, at the 8th day, the mice were taken vaginal smears twice daily (09:00 and 16:00) for 12 consecutive days. The feature of vulva in the mice and vaginal smear cytology, occurrence rate of regular estrous cycle, duration of estrous cycle and each stage duration of estrous cycle were recorded and observed. RESULTS: The characteristics of estrous cycle in normal group and sham operation group were similar. Nearly 85% of the ICR mice in sexual maturity stage showed regular estrous cycle. The majority manifested 6-day cycle (83%), and only a small number exhibited 5-day cycle (17%). Compared with 5-day group, the duration of oestrus was significantly increased in 6-day group (P<0.05). The number and kind of the cells in vaginal smear were a little different between 5-day and 6-day groups. The ovariectomized mice which showed irregular estrous cycle (76%) were characterized by continuous diestrus. CONCLUSION: Female ICR mice have the strain characteristics of estrus cycle.     

Effects of folic acid on antioxidant enzyme,nitric oxide synthase and nitric oxide in ovariectomized rats

AIM: To observe the effects of folic acid (FA) on antioxidant enzyme, nitric oxide synthase (NOS) and nitric oxide (NO) in ovariectomized (OVX) rats.METHODS: Forty three-month-old female SD rats were randomly divided into 5 groups: sham group, OVX group, diethylstilbestrol group (0.03 mg·kg^-1·d^-1), low-dose FA group (5 mg·kg^-1·d^-1) and high-dose FA group (20 mg·kg^-1·d^-1). Gastric gavage started 1 week after operation and lasted for 10 weeks. The rats in sham group and OVX group were given distilled water instead of FA as controls. At the end of the 10th week, the L₅ vertebra and right femur were removed for determination of bone mineral density (BMD). The bone homogenates were made using the L₃ and L₄ vertebrae. The levels of the total antioxidant capacity (TAC), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), NOS and NO were detected in plasma and bone homogenates.RESULTS: Compared with sham group, the BMD levels in L₅ vertebra and right femur and the levels of GSH-Px and NO in the plasma were all decreased. The levels of TAC, GSH-Px, NOS and NO in the bone homogenates were also decreased, while the MDA concentration was increased in OVX group (all P < 0.01). Compared with OVX group, the levels of TAC, GSH-Px, NOS, NO and BMD of the L₅ vertebra and right femur were all increased, while the MDA concentration was decreased in high-dose FA group (all P < 0.01). CONCLUSION: In female SD rats, ovariectomy leads to a significant reduction of antioxidant enzyme, NOS and NO levels. Oxidative stress is possibly involved in the development of osteoporosis. Protection against osteoporosis by high-dose FA may be linked to improvement of antioxidant enzyme activity, the levels of NOS and NO as well as a reduction of oxidative stress in ovariectomized rats.     

Protective effect of progesterone on PC12 cells injured by oxygen-glucose deprivation

AIM: To investigate the effects of progesterone on the cell viability and expression of glucose transporter type 3(GLUT3) in PC12 cells injured by oxygen-glucose deprivation (OGD) in attempt to prove the neuroprotection of progesterone (PROG) against the hypoxic-ischemic injury in cultured cells in vitro. METHODS: Well-differentiated PC12 cells induced by nerve growth factor were randomly divided into 3 groups. In normal group, the cells were cultured without OGD treatment. In OGD group, the culture medium was replaced by glucose-free medium and the cells were transferred to a humidified incubation chamber flushed by a gas mixture of 95% N₂ and 5% CO₂ for 30 min. After that, the cells were fed with glucose-supplemented medium and cultured under normoxic condition for 24 h. In PROG+OGD group, the cells were given the same treatments as those in OGD group except that the medium contained progesterone at concentration of 10 nmol/L. Cellular morphological changes were observed after OGD for 30 min. The cell viability was assessed by WST-8 assay. The degree of the cell damage was evaluated by determining lactate dehydrogenase (LDH) leakage. The expression of GLUT3 at mRNA and protein levels was examined by RT-PCR and Western blotting, respectively. RESULTS: Progesterone attenuated the cellular swelling, decreased the leakage of LDH and improved the viability of PC12 cells injured by OGD (P<0.01). The expression of GLUT3 at mRNA and protein levels in PC12 cells in PROG+OGD group was significantly higher than that in OGD group (P<0.05). CONCLUSION: Progesterone has protective effect on in vitro cultured PC12 cells injured by OGD. The mechanism may be related to the up-regulation of GLUT3 protein.     

Effects of sodium ferulate on function of macrophages in the colonic tissue of colitis rats

AIM: To explore the effects of sodium ferulate (SF) on function of macrophages in colonic tissue of the colitis rats in vivo. METHODS: The immunological colitis model of rats was produced. SF was used intracolonically for 21 days. The contents of malondialdehyde (MDA), nitric oxide (NO), prostaglandin E₂ (PGE₂) and the activity of superoxide dismutase (SOD), interleukin-1 (IL-1), TNF-α, myelopexoxidase (MPO), and the expression level of NF-κB p65 in colonic tissue of the rats were detected. RESULTS: SF (200,400,800 mg/kg) decreased the elevated contents of MDA, NO, PGE₂, the activity of IL-1, TNF-α, MPO, and the expression level of NF-κB p65, while increased the reduced activity of SOD in colonic tissue of the colitis rats in a dose-depended manner. CONCLUSION: SF restrained the activity of activated colonic macrophages and relieved the colonic inflammation reaction in vivo in colitis rats, which may be related to the suppression of NF-κB activation.     

Effects of icariin on expression of transforming growth factor β1 and type Ⅳ collagen in diabetic rat testis

AIM: To determine the beneficial effects of icariin on streptozotocin (STZ)-induced diabetic testopathy in rats. METHODS: The diabetic animal model was induced in male Sprague-Dawley rats by an injection of streptozotocin (40 mg/kg, iv). The rats were randomly divided into 3 groups: control group, model group and icariin (80 mg/kg, ig) group. Twelve weeks after injected with streptozotocin, all rats were anaesthetized and killed to remove the testes from scrotum. Serum concentrations of glucose and testosterone, and the levels of succinate dehydrogenase (SDH), acid phosphatase (ACP), γ-glutamyl transpeptidase (γ-GT) and lactate dehydrogenase (LDH) in testes were measured. The morphology of the testicular tissues was observed under light microscope. Immunohistochemistry was employed to determine the protein levels of TGF-β₁ and type Ⅳ collagen. RESULTS: Compared with control group, the content of serum glucose increased while the serum level of testosterone and the activitiy of SDH, ACP, γ-GT and LDH in testis decreased in model group (P<0.01). The histopathological examination showed that the diameters of seminiferous tubules and various grades of spermatocytes in the testis were markedly decreased. Compared with control group, the expression of TGF-β₁ and collagen Ⅳ was significantly increased in model group. These alterations were significantly attenuated in icariin group (P<0.01). CONCLUSION: Icariin evidently relieves testicular damage in rats with diabetic testopathy by improving the secretion of testosterone and reducing the expression of TGF-β₁ and collagen Ⅳ at protein level.     

Estrogen affects reactivity of rat mesenteric artery through ATP-sensitive potassium channel

AIM: To observe the expression of ATP-sensitive potassium (K_ATP) channel mRNA in mesenteric artery smooth muscle of rats with estrogen administration, and to evaluate the role of K_ATP channel in the effects of estrogen on the reactivity of mesenteric artery in rats. METHODS: Forty-eight female Sprague-Dawley rats, weighing (100?10) g, were randomly divided into 3 groups: sham operation (sham) group, ovariectomy (Ovx) group and ovariectomy with estrogen administration (Ovx+E) group. The mRNA expression of K_ATP subunits in mesenteric artery smooth muscle was detected by quantitative real-time PCR. Artery reactivity in the rats was observed by norepinephrine-induced pressor response. RESULTS: Compared with sham group, the mRNA expression of Kir6.1 and SUR2B was significantly decreased in Ovx group (P<0.05), but increased in Ovx+E group (P<0.05). Compared with sham group and Ovx+E group, the pressor response induced by norepinephrine in the rats were enhanced in Ovx group (P<0.05). No significant difference between sham group and Ovx+E group was observed. After administered with glibenclamide (a K_ATP channel blocker), the pressor response induced by norepinephrine was enhanced in sham group and Ovx +E group, and no changes in Ovx group. Meanwhile, no difference among the 3 groups was found. CONCLUSION: Estrogen up-regulates the expression of K_ATP channel subunits, which may be involved in estrogen-reduced pressor response to norepinephrine.     

不同红蓝LED组合光源对叶用莴苣光合特性和品质的影响及节能评价

 为了探求适合叶用莴苣生长的节能高效的光源参数,采用红、蓝光波峰组合分别为红光（R）660 nm + 蓝光（B）450 nm的LEDA型和红光（R）630 nm + 蓝光（B）460 nm的LEDB型光源,每种光源设置R/B分别为6、8和10的3种比例,处理叶用莴苣。结果表明：LEDA型与LEDB型光源处理的叶用莴苣光合速率、蒸腾速率、气孔导度、胞间CO2浓度、维生素C、总糖和硝酸盐含量均无显著差异,但均较荧光灯光源（对照）显著提高了光合速率。两种光源不同R/B处理的上述指标变化趋势一致,均表现为R/B = 8时（LEDA2、LEDB2）最优,其中LEDA2处理比荧光灯处理光合速率提高38%,维生素C含量增加8.3%,硝酸盐含量降低9.2%;LEDB2处理时光合速率提高48%,硝酸盐含量降低6.5%。LEDA型光源处理的叶绿素a、b和（a + b）含量显著高于LEDB型光源处理,且分别表现为LEDA3和LEDB2处理的含量最高。此外,对光源装置耗电量的计算表明,LEDB型光源的单株耗电量比LEDA型和荧光灯（对照）分别节省53.3%和27.7%。因此,红、蓝光波峰分别为630 nm + 460 nm的组合LED光源,R/B = 8的条件下,在提高叶用莴苣光合速率和品质以及降低耗电量3个方面体现优势。