Inhibition of Gonadotropin and Prostaglandin Stimulation of Testicular Steroidogenesis in Malnourished Rats

The effect of human chorionic gonadotropin (hCG) and prostaglandin E1 (PGE1) on testicular steroidogenesis in protein-deficient and refed rats was studied in vitro. The malnourished, refed, and control rats were found to secret testosterone in response to hCG and PGE1 stimulation. There was a significant reduction in the basal level of secretion in the malnourished rat testis (1.0 +/- 0.4 nMol/3 hr./Testis). Malnourished rats refed with adequate protein diet responded to hCG and PGE1 stimulation in a similar manner to normally-fed adult rats.     

Intratesticular factors and testosterone secretion: The effect of treatment with ethane dimethanesulphonate (EDS) and the induction of seminiferous tubule damage

The role of seminiferous tubule dysfunction in regulating the levels of a factor (or factors) in testicular interstitial fluid (IF) which stimulates Leydig cell testosterone secretion in vitro, was assessed by injecting rats with the Leydig cell toxin, EDS. Within 72 h of treatment EDS destroyed the Leydig cells and concomitantly reduced IF testosterone to undetectable levels. This was associated with nearly a 2-fold increase (P less than 0.001) in levels of the IF-factor(s) as judged by the enhancement of hCG-stimulated testosterone production (= IF bioactivity). By 3 weeks, and thereafter up to 10 weeks post-EDS, Leydig cells regenerated within the testis, and testosterone levels returned to control values, but IF-bioactivity remained significantly increased. The latter was associated with seminiferous tubule dysfunction as indicated initially by testicular morphology, raised serum levels of FSH and reduced testicular weight. For animals with normal testosterone levels, there was a significant negative correlation (r = -0.57, N = 46; P less than 0.001) between testicular weight and IF bioactivity. A similar increase in IF bioactivity in the presence of normal testosterone levels was observed in rats in which patchy severe seminiferous tubule damage had been induced by short-term cryptorchidism. It is concluded that, in addition to testosterone, seminiferous tubule function may dictate the intratesticular levels of the testosterone-stimulating factor(s) in IF.     

Evidence for a direct role of cyclo-oxygenase 2 in implant wear debris-induced osteolysis.

Aseptic loosening is a major complication of prosthetic joint surgery and is manifested as chronic inflammation, pain, and osteolysis at the bone implant interface. The osteolysis is believed to be driven by a host inflammatory response to wear debris generated from the implant. In our current study, we use a selective inhibitor (celecoxib) of cyclo-oxygenase 2 (COX-2) and mice that lack either COX-1 (COX-1-/-) or COX-2 (COX-2-/-) to show that COX-2, but not COX-1, plays an important role in wear debris-induced osteolysis. Titanium (Ti) wear debris was implanted surgically onto the calvaria of the mice. An intense inflammatory reaction and extensive bone resorption, which closely resembles that observed in patients with aseptic loosening, developed within 10 days of implantation in wild-type and COX-1-/- mice. COX-2 and prostaglandin E2 (PGE2) production increased in the calvaria and inflammatory tissue overlying it after Ti implantation. Celecoxib (25 mg/kg per day) significantly reduced the inflammation, the local PGE2 production, and osteolysis. In comparison with wild-type and COX-1-/- mice, COX-2-/- mice implanted with Ti had a significantly reduced calvarial bone resorption response, independent of the inflammatory response, and significantly fewer osteoclasts were formed from cultures of their bone marrow cells. These results provide direct evidence that COX-2 is an important mediator of wear debris-induced osteolysis and suggests that COX-2 inhibitors are potential therapeutic agents for the prevention of wear debris-induced osteolysis.     

Selective COX-2 inhibition is favorable to human early and late-stage osteoarthritic cartilage: a human in vitro study

OBJECTIVE: Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used in the treatment of osteoarthritis (OA). For the outcome of treatment the direct effects of NSAIDs on cartilage may be more important than indirect effects on inflammation, considered being secondary in OA. For clinical practice, it is relevant to study effects of NSAIDs on early stages of OA. Therefore we studied the direct effects of celecoxib on human degenerated OA cartilage and compared the effects with those on human healthy cartilage and human end-stage OA cartilage. METHODS: Degenerated, late-stage OA, and healthy human articular cartilage were exposed (7 days of culture) to celecoxib (0.1-10 microM). Changes in cartilage proteoglycan turnover (synthesis, retention, and release), proteoglycan content, prostaglandin E2 (PGE2) and nitric oxide (NO) production were determined. RESULTS: Both degenerated and established OA cartilage showed its characteristic changes in proteoglycan turnover (all P<0.05). Celecoxib at 1 microM was able to increase synthesis of degenerated cartilage and normalize both releases of newly formed and resident proteoglycans. Importantly, 1 microM celecoxib influenced matrix integrity by enhancing proteoglycan content. Similar results were found for end-stage OA cartilage. Enhanced PGE2 production in degenerative and OA cartilage could be decreased by celecoxib, whereas no effect on enhanced NO production was found. No significant effects of celecoxib on normal cartilage were found. DISCUSSION: Celecoxib, in a clinical relevant concentration, showed in vitro a significant beneficial effect, not only on late-stage OA but also on more early stages of OA, whereas healthy cartilage remained unaffected, suggesting chondroprotective properties of celecoxib in the treatment of degenerative joint disorders.     

Regulatory cytokine expression and interstitial fluid formation in the normal and inflamed rat testis are under leydig cell control

Leydig cells have been implicated in several inflammation-related responses of the testis. Specifically, these cells produce the proinflammatory cytokines interleukin-1 (IL-1) and IL-6, stimulate macrophage recruitment, and promote interstitial fluid formation. In addition, the immunoregulatory cytokines macrophage migration inhibitory factor (MIF), transforming growth factor-beta1 (TGFbeta1), and interferon-gamma (IFNgamma) are constitutively expressed by testicular cells, including the Leydig cells. In the present study, the contribution of the Leydig cell to testicular inflammatory responses was examined in adult male rats treated with the Leydig cell-specific toxin, ethane dimethane sulfonate (EDS). Intratesticular testosterone levels were modulated by subcutaneous testosterone implants. After 10 days, animals received an injection of lipopolysaccharide (LPS) to induce an inflammatory response, or saline alone, and were killed 3 hours later. Both depletion of Leydig cells by EDS and LPS treatment caused a decrease in collected testicular interstitial fluid to about 35% of control levels, but the effects were not additive. Maintenance of intratesticular testosterone reversed the interstitial fluid decline following EDS treatment and partially prevented the LPS-induced effect. MIF, TGFbeta1, and IFNgamma were expressed in both the normal and inflamed testis at similar levels. In contrast, EDS treatment caused a significant decline in expression of all 3 cytokines, which was prevented by the testosterone implants. These data indicate that 1) expression of TGFbeta1, MIF, and IFNgamma in the testis is not dependent on the presence of intact Leydig cells but is under direct testosterone control and 2) the decline in testicular interstitial fluid during inflammation involves the Leydig cells, acting via both androgens and nonandrogenic secretions. These data provide further support for a significant role for the Leydig cell in modulating the testicular response to inflammation.     

Changes in the secretion of ABP into testicular interstitial fluid with age and in situations of impaired spermatogenesis

Androgen-binding protein (ABP) was measured in serum and testicular interstitial fluid (IF) from rats during sexual maturation or in adult rats in which impairment of spermatogenesis had been induced by (i) testosterone withdrawal following Leydig cell destruction, (ii) local heating (43 degrees C) of the testes for 30 min or (iii) induction of unilateral cryptorchidism (UCD). The changes observed were related to the IF levels of testosterone and, in most instances, to the serum levels of FSH. The levels of ABP in serum and IF decreased together with age, being highest at 30 days, falling steeply by 40 days and then slowly but progressively up to 100 days of age. A similar pattern was observed for serum FSH, except that the initial fall occurred beyond 40 days of age. Treatment with EDS or exposure to local heating caused comparable reductions in testicular weight (25-30% by 7 days after treatment, 50% by 21-28 days) and raised the serum levels of FSH. In both groups the levels of ABP in IF were increased by two- to three-fold while the levels of testosterone were either reduced markedly (EDS-treatment) or remained unchanged (local heating). In rats made UCD for 60 days, the weight of the abdominal testis was reduced by 75%, compared with the contralateral scrotal testis, while the IF levels of ABP and testosterone were significantly increased (55%) and decreased (90%), respectively. Short-term (3 days) deprivation of testosterone in adult rats, following immunoneutralization of LH, was without significant effect on IF levels of ABP. It is concluded that ABP secretion into IF is increased in situations of subnormal (or sub-adult) numbers of germ cells and this is usually associated with high levels of FSH. Measurement of ABP levels in IF should prove of value for the monitoring of Sertoli cell function in vivo and may be of diagnostic use for the detection of changes in germ cell numbers.     

塞来昔布联合奥沙利铂对人结肠癌裸鼠移植瘤生长的抑制作用

目的 观察塞来昔布或联合奥沙利铂对人结肠癌裸鼠移植瘤生长的影响并探讨其机制.方法 用人结肠癌HT-29细胞建立移植瘤模型,将裸鼠随机分为对照组、奥沙利铂组、塞来昔布组、联合用药组.给予相应药物35 d后,取移植瘤组织检测COX-2,VEGF mRNA和微血管密度.结果 塞来昔布组、奥沙利铂组和联合用药组抑瘤率分别为34.94%、30.53%和62.87%.奥沙利铂组COX-2,VEGF表达显著高于对照组(分别P＜0.05).奥沙利铂组微血管密度与对照组比较差异无统计学意义(P＞0.05).塞来昔布组和联合用药组COX-2,VEGF和MVD与对照组比较均显著下降(分别P＜0.05).结论 塞来昔布可抑制人结肠癌裸鼠移植瘤的生长和肿瘤血管生成.塞来昔布增加了奥沙利铂的抗肿瘤效果.     

睾酮在精子生成过程中分泌动力学的实验研究

目的　研究睾酮在精子生成过程中的作用浓度。　方法　对ＳＤ 大鼠的精索静脉分别作双、单侧高位结扎后３、２１ 天睾丸间液及不同部位血清的睾酮浓度进行测定,并观察睾丸显微结构的变化。　结果　大鼠体内睾丸间液睾酮浓度最高;血清睾酮浓度依次为睾丸静脉［（４２－５０３ ±１２－７４９） ｍｇ／Ｌ］ 、近端精索静脉［（４２－５０３±１２ ．７４９） ｍｇ／Ｌ］ 、睾丸动脉［（５－５９８ ±３－６４９）ｍｇ／Ｌ］ 、尾静脉［（２．５３３±１－７１９） ｍｇ／Ｌ］和下腔静脉血［（２－４１８ ±１－４９５） ｍｇ／Ｌ］ 。双侧精索内静脉结扎后３ 天,双侧睾丸重量、血清和睾丸间液睾酮浓度均显著下降。左侧精索内静脉结扎后３ 天,左侧睾丸重量、睾丸动脉和睾丸间液睾酮浓度均显著下降;其余在正常水平。所有结扎侧睾丸精曲小管上皮轻度变性,并伴有部分结构不清。２１ 天后均恢复正常。　结论睾酮在体内除了正常循环外,还可能存在１ 个从睾丸睾丸静脉精索静脉精索动脉睾丸动脉睾丸的“小循环”。近端精索静脉的结扎对睾丸内的睾酮浓度和睾丸结构的影响是暂时性的,能自行恢复和修复     

Preoperative chemoradiation followed by transanal excision for rectal cancer

BACKGROUND: Omega-3 fatty acids (n-3 FA) demonstrate significant anti-inflammatory properties thought to occur through three principal mechanisms; (1) displacement of arachidonic acid from the cellular membrane, (2) differential prostaglandin E2 (PGE2) and LTB4 production, and (3) molecular level alterations such as diminished nuclear factor kappa B and AP-1 activation. Recently, n-3 FA have been demonstrated to significantly decrease nitric oxide (NO) production in a lipopolysaccharide (LPS)-stimulated M Phi model. We hypothesized that decreased NO production by n-3 FA occurs through inhibition of cyclooxygenase-2 (COX-2) derived PGE2 and that repletion of the system with PGE2 would obliterate these effects. Selective COX-2 inhibitor (L-748,731) experiments and separate PGE2 repletion studies were used to test this hypothesis. METHODS: NO production was assessed following 24 h with or without LPS/PGE2 in the presence of n-3 FA, L-748,731 (a selective COX-2 inhibitor), or combination (n-3 FA + L-748,731) treatment. Western blots were used to assess inducible NO synthase protein expression. RESULTS: Independently or in the presence of LPS, treatment with a COX-2 inhibitor significantly increased NO production compared with control, n-3 FA, and combination treatment. NO production in combination treatment is slightly increased compared to n-3 FA treatment. In control cells treated with LPS, PGE2 repletion resulted in a significant decrease in NO. All other treatment groups repleted with PGE2 demonstrated no significant alterations in NO production. Inducible NO synthase protein expression levels were similar to NO production across all treatments. CONCLUSION: These experiments disproved our original hypothesis that the decrease in NO production associated with n-3 FA treatment occurs through a COX-2 derived PGE2 dependent mechanism. Eliminating COX-2 derived PGE2 by a selective inhibitor actually increased NO production. Exogenous PGE2 repletion did not restore the system. Therefore, mechanisms other than n-3 FA associated alterations in COX-2 derived PGE2 are likely involved in decreasing NO production in LPS stimulated M Phi.     

Mechanism of Reversible Loss of Reproductive Capacity in a Seasonally-Breeding Mammal

Reversible loss of fertility which occurs annually in seasonally-breeding species appears due to changes in the release of pituitary hormones, the levels of gonadal hormone receptors and the sensitivity of the hypothalamic-pituitary system to inhibition by gonadal steroids. In the golden hamster, exposure to a short photoperiod causes reduction in plasma prolactin (PRL) levels, loss of testicular LH receptors, and gonadal atrophy. Reduction in plasma PRL is probably not secondary to inhibition of testicular steroidogenesis because it cannot be induced by castration or reversed by administration of testosterone. Treatment of gonadally regressed hamsters with PRL increases testicular weight, spermatogenesis, concentration of LH receptors in the testis and plasma testosterone levels. Prolactin-producing ectopic pituitary homografts prevent loss of LH receptors and delay gonadal regression in animals transferred from a long to a short photoperiod. Treatment of adult male hamsters with PRL can increase plasma FSH levels. It is concluded that changes in PRL release play an important role in mediating the effects of photoperiod on testicular activity in the golden hamster.     

Cyclooxygenase-2 (COX-2) inhibition limits abnormal COX-2 expression and progressive injury in the remnant kidney

BACKGROUND: The pathogenesis of progressive nephropathies involves hemodynamic and inflammatory factors. In the 5/6 nephrectomy model, a selective increase of cyclooxygenase-2 (COX-2) expression was shown, whereas treatment with a nonsteroidal anti-inflammatory or a specific COX-2 inhibitor was renoprotective. We investigated in the 5/6 nephrectomy model (1) the renal distribution of COX-2; (2) the hemodynamic and cellular mechanisms by which chronic COX-2 inhibition prevents renal injury. METHODS: After 5/6 nephrectomy, adult male Munich-Wistar rats were subdivided in two groups: 5/6 nephrectomy (N=20), receiving vehicle, and 5/6 nephrectomy + celecoxib (N=19), treated orally with the COX-2 inhibitor, celecoxib, 10 mg/kg/day. Untreated and treated (celecoxib) sham-operated rats were also studied. Renal hemodynamics were examined at 4 weeks, whereas renal morphologic/immunohistochemical studies were carried at 8 weeks. RESULTS: At 4 weeks, 5/6 nephrectomy rats exhibited marked systemic and glomerular hypertension. Celecoxib attenuated both systemic and glomerular hypertension, without affecting glomerular filtration rate (GFR). At 8 weeks, glomerulosclerosis and interstitial expansion were evident in 5/6 nephrectomy rats, and markedly attenuated in 5/6 nephrectomy rats given celecoxib. In both sham-operated and 5/6 nephrectomy rats, COX-2 was expressed at the macula densa. The extent of COX-2 expression at the macula densa was nearly tripled by celecoxib, indicating the existence of a feedback mechanism. In 5/6 nephrectomy rats, COX-2 was also expressed in glomeruli, arterioles, and the cortical interstitium, mostly at inflamed or sclerosing areas. Celecoxib markedly attenuated renal injury, inflammation, and ectopic COX-2 expression in 5/6 nephrectomy rats. CONCLUSION: Chronic COX-2 inhibition attenuated progressive nephropathy by reducing glomerular hypertension, renal inflammation, and ectopic COX-2 expression, indicating a complex contribution of COX-2 to progressive renal injury in 5/6 nephrectomy rats.     

塞莱昔布超前镇痛用于膝关节镜手术的研究

目的 研究塞莱昔布超前镇痛对膝关节镜手术术后疼痛、关节活动情况及关节液内前列腺素E2(PGE2)的影响.方法 将40例膝关节镜手术患者随机均分为观察组和对照组,观察组术前3 d给予塞莱昔布200 mg,每天2次;对照组给予安慰药(复合维生素片).采用联合腰麻,手术开始前抽取关节液1～2 ml,检测PGE2浓度.术前、手术结束及术后2、4、8、12、24、48 h进行镇痛效果评估,观察术后膝关节活动情况.结果 观察组关节液中PGE2浓度明显低于对照组(P＜0.01).观察组术前VAS明显低于对照组(P＜0.01),术后各时点VAS两组间差异无统计学意义;但观察组术后膝关节活动度明显大于对照组(P＜0.05).结论 塞莱昔布超前镇痛用于膝关节镜手术,能明显减轻炎症反应,增加术后膝关节活动度,有利于术后恢复.     

Synergistic tumoricidal effect between celecoxib and adenoviral-mediated delivery of mda-7 in human breast cancer cells

BACKGROUND: Celecoxib, a selective cyclooxygenase 2 (COX-2) inhibitor, blocks growth and promotes apoptosis in breast cancer cells. The PI3K/Akt pathway is important in cell survival, and COX-2 and Akt might promote growth via a positive feedback loop. We have shown that adenoviral delivery of mda-7 (Ad-mda7) in breast cancer down-regulates Akt. We hypothesized that combining Ad-mda7 and celecoxib could mediate tumor suppression in COX-2 overexpressing breast cancer cells. METHODS: Two COX-2 overexpressing human breast cancer cell lines (Her-18 and MDA-MB-436) were treated with celecoxib (20 micromol/L and 50 micromol/L) and Ad-mda7 (multiplicity of infection, 1000 and 2000 viral particles/cell). Adenovirus encoding the luciferase gene was used as a control. We assessed proliferation, cell cycle, apoptosis, prostaglandin E2 production, and changes in protein expression. Statistical analysis was performed by using the Student t test. RESULTS: Regardless of HER-2/neu status, cell growth was markedly inhibited by celecoxib, Ad-mda7, and the combination compared with controls. Celecoxib + Ad-mda7 showed a greater than additive increase in cell death compared with either monotherapy (P < .05) and resulted in cell cycle block and apoptosis (P < .05). Both cell lines showed decreased prostaglandin E2 production after combination treatment compared with controls (P < .05), with decreased expression of COX-2, Akt, and phosphorylated Akt (P < .05). CONCLUSIONS: Enhanced antitumor activity is achieved in breast cancer by combining celecoxib and Ad-mda7 regardless of HER-2/neu status. This occurs through inhibition of COX-2 expression and down-regulation of Akt. Combining Ad-mda7 with COX-2 inhibition provides a novel method of treatment in breast cancer.     

Evaluation of the relative importance of endocrine and paracrine factors in control of the levels of inhibin in testicular interstitial fluid

This study aimed to identify the role of endocrine (FSH, LH, testosterone) or paracrine (Leydig or germ cell) factors in control of the secretion of inhibin into testicular interstitial fluid (IF). This was done by measuring inhibin and testosterone levels in IF, and serum gonadotrophin and testosterone levels in adult rats following the destruction of Leydig cells with ethane dimethane sulphonate (EDS), alone or in combination with testosterone ester (TE) supplementation at various doses initiated at various times after EDS treatment. The effect of germ cell loss (induced by local testicular heating) on its own or in combination with the above treatments was also assessed. Treatment with EDS led to major increases in the levels of inhibin in IF and of FSH and LH in serum whilst testosterone levels in IF and serum fell to undetectable levels. Supplementation with TE (1-25 mg) for 21 days from the time of EDS treatment failed to prevent the initial (+3 days) increase in IF levels of inhibin but thereafter suppressed inhibin to control levels or lower and grossly suppressed FSH and LH levels, irrespective of whether the dose of TE administered did (25 or 5 mg) or did not (1 mg) prevent major seminiferous tubule damage. Partial regeneration of Leydig cells and normalization of testosterone levels occurred in rats 21 days after treatment with EDS alone but this failed to normalize inhibin and gonadotrophin levels. When supplementation with TE (25 mg) was initiated at 3, 6 or 9 days after EDS treatment, IF levels of inhibin were normalized within 3 days and maintained thereafter in parallel with suppression of serum FSH and LH to below control levels. Seminiferous tubule damage induced by local testicular heating (43 degrees C for 30 min) led to increased IF levels of inhibin 3 and 14 days later, in parallel with increased serum levels of FSH (but not LH). Suppression of FSH to subnormal levels in heat-exposed rats by TE treatment (25 mg) restored IF inhibin to control levels or below, a change which still occurred when Leydig cells were destroyed by EDS treatment. It is concluded that secretion of inhibin via the base of the Sertoli cell into testicular IF is controlled primarily by FSH, although local factors may play a minor role. These findings have important implications regarding the possible paracrine role(s) of inhibin in IF during puberty and in the normal adult testis.     

PGE2 and IL-6 production by fibroblasts in response to titanium wear debris particles is mediated through a Cox-2 dependent pathway.

Aseptic loosening of orthopaedic implants is precipitated by wear debris-induced osteolysis. Central to this process are the pro-inflammatory mediators that are produced in response to wear by the fibroblastic cells, which comprise the majority of periprosthetic membranes. Since this pro-inflammatory cascade is mediated by a plethora of factors with redundant functions, it is imperative to establish a hierarchy. Two well-known fibroblast derived pro-inflammatory factors that stimulate wear debris-induced osteoclastic resorption are prostaglandin E2 (PGE2) and IL-6. However, their relationship to each other in this process is poorly defined. Here we show immunohistochemistry of retrieval membranes indicating that COX-2 is the principal cyclooxygenase responsible for PGE2 production in fibroblasts around failed implants. We also performed in vitro experiments with fibroblasts derived from wild-type (WT), COX-1 (-/-) and COX-2 (-/-) mice, which demonstrated that COX-2 is required for Ti wear debris-induced PGE2 production. Interestingly, COX-2 was also required for IL-6 production in these assays, which could be rescued by the addition of exogenous PGE2 (10(-6) M). Pharmacology studies that utilized the COX-1 selective inhibitor SC 560, the COX-2 selective inhibitor celecoxib, and the nonselective COX inhibitor indomethacin confirmed these results. Taken together, these results indicate that selective inhibition of prostaglandin signaling could favorably impact aseptic loosening beyond its direct effects on PGE2 synthesis, in that it inhibits downstream pro-inflammatory/pro-osteoclastic cytokine production.     

The effects of maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin on testicular steroidogenesis in infantile male rats

Exposure of adult male animals to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) decreases serum androgen concentrations. Reduction in androgen levels after maternal exposure has also been reported, but these results have not been reproduced. We have earlier shown that TCDD stimulates rather than inhibits testosterone synthesis in the prenatal rat testis. The aim of the present study was to elucidate in utero-induced effects of TCDD on testicular steroidogenesis in the 14-day-old infant rats. At that time the foetal Leydig cell population is still the prevailing source of androgens. Pregnant Sprague-Dawley dams were given a single oral dose of TCDD (0, 0.04, 0.2, or 1.0 microg/kg) on day 13 of pregnancy. On postnatal day 14, the body weight of male offspring was reduced after exposure to 1.0 microg/kg TCDD (from 33.9 +/- 1.66 g to 31.6 +/- 2.67 g). Relative testis weight, plasma testosterone, luteinizing hormone and follicle-stimulating hormone levels remained unaltered in all exposure groups. Moreover, in ex vivo incubations, testosterone and cAMP production was not affected. StAR protein level in the freshly isolated testes was increased in the 0.2 microg/kg group, and seminiferous cord diameter in the 0.04 microg/kg group. The present study confirms our earlier findings in in utero TCDD-exposed foetal testis indicating that maternal TCDD exposure does not negatively influence the developmental testosterone production of foetal type Leydig cells in rats.     

Influence of rat testicular macrophages on Leydig cell function in vitro

The influence of co-cultures of rat testicular macrophages and Leydig cells (LC) on LC morphology and steroidogenesis was investigated with and without macrophage stimulation by a bacterial lipopolysaccharide (LPS). LC showed an elongated form in the presence of stimulated testicular macrophages. In the presence of non-stimulated testicular macrophages a significant inhibition of testosterone production was observed (decrease of 33%) from 48 h in co-culture while an increase of 16% was obtained at the same culture time, after stimulation of macrophages by LPS. When LC were treated with testicular macrophage-conditioned media (MCM) obtained from LPS-treated macrophages, they became fusiform and there was stimulation (78%) of steroid production. After human FSH stimulation (1-1000 mIU ml-1), MCM from testicular macrophages was no more effective in enhancing testosterone production by LC than was media from untreated LC. Similar experiments with LPS were conducted with macrophages of peritoneal origin. Peritoneal macrophages stimulated or not by LPS in co-cultures with LC or peritoneal MCM did not significantly modify testosterone production. However, these cells were able to modify LC morphology when LPS-MCM was added to LC-culture medium. The present results suggest strongly that testicular macrophage-LC interactions could be important in the control of LC steroidogenesis.     

塞来昔布(celecoxib)通过前列腺素E2途径影响胆管癌细胞株生长和凋亡

目的：研究塞来昔布（celecoxib)对环氧合酶－2（COX－2）高表达人胆管癌细胞系QBC939和COX－2低表达人胆管癌细胞系SK－Cha-1生长和凋亡的影响及其作用机制。方法：采用四唑盐（MTT）比色法检测细胞增殖，光镜和电镜形态学观察，末端脱氧核苷酸转移酶介导的原位酶标记法（TUNEL）计数细胞凋亡，流式细胞仪测定细胞周期，酶联免疫吸附测定（ELISA）检测前列腺素E2（PGE2）含量。结果：塞来昔布抑制QBC939生长和诱导调亡，这种抗增殖作用能被PGE2拮抗；塞来昔布对结构性低表达COX－2胆管癌细胞SK－Cha-1无显著性作用。结论：塞来昔布通过PGE2途径抑制人胆管癌细胞生长和诱导凋亡。针对COX－2结构性高表达肿瘤塞来昔布可能是一种有效的化学治疗和化学预防药物。