Lactational exposure of polychlorinated biphenyls downregulates critical genes in Leydig cells of F1 male progeny (PND21)

Polychlorinated biphenyls (PCBs) are environmental contaminants. The present study was aimed to test the effect of lactational exposure of PCBs on Leydig cellular mRNA and protein expressions of 5α‐reductase, aromatase and androgen receptor (AR) in F1 male offspring. Lactating dams were orally gavaged with different doses of PCBs (Aroclor 1254) 0, 1, 2 and 5 mg kg b.wt^?1 day^?1, respectively, from PND1 to PND21. Male offsprings were sacrificed at PND21. Testes were used to isolate Leydig cells. Blood was collected. Serum testosterone (T) and oestradiol (E₂) were measured. Anogenital distance was measured. Dams’ milk lipid and serum lipids of male pups were estimated. PCB (Aroclor 1254) concentration of dams’ milk and serum of male pups were analysed by GC‐ECD. Leydig cellular mRNA and protein expressions of 5α‐reductase, aromatase and AR were significantly decreased. Our data suggest that lactational exposure of PCBs downregulates selected genes in Leydig cells of F1 generation on post‐natal day 21.     

酒精对大鼠前列腺抗氧化酶活性和脂质过氧化的影响

目的 探讨酒精对大鼠前列腺组织抗氧化酶活性和脂质过氧化水平的影响。方法 40只成年健康SD雄性大鼠随机均分为对照组、低剂量组、中剂量组和高剂量组，分别用50．0％、25．0％、12．5％的乙醇溶液和蒸馏水按10．0ml／kg每晚灌胃1次持续60d后，观察酒精毒染模型大鼠前列腺组织的形态结构的变化；用化学比色法测定前列腺组织中超氧化物岐化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）、丙二醛（MDA）和前列腺酸性磷酸酶（PAP）的水平。结果 随着酒精剂量的增加，SOD、CAT、GSH-Px活力和PAP含量呈先升高后下降的趋势，MDA含量和前列腺相对重量分别呈现上升和下降趋势，前列腺组织馆牛棼缩。结论 长期过量饮洒可导致大鼠前列腺绸织结构和功能异常，氧化应激在其中发挥了重要作用。     

Effects of testosterone and vitamin E on the antioxidant system in rabbit testis

The aim of the study was to investigate the effects of testosterone propionate and vitamin E on the antioxidant system in the testis. Thirty-two male New Zealand White rabbits were randomly divided into four groups. The first group was used as control. The second group was injected with testosterone propionate, the third group vitamin E and the fourth group vitamin E and testosterone propionate combination. All treatments were carried out during 6 weeks and oxidative parameters were evaluated in homogenized testicular tissue. The levels of vitamin E and the activity of glutathione peroxidase were lower (P < 0.05) in the testosterone group than in controls. However, vitamin C and malondialdehyde levels were higher (P < 0.05) in this group than in controls. The levels of reduced glutathione, beta-carotene, vitamin C and E increased, but malondialdehyde levels decreased in the vitamin E group, when compared with controls (P < 0.05). Vitamin E and beta-carotene levels were significantly higher (P < 0.05) in the combination group than in testosterone group. However, MDA levels were lower (P < 0.05) in combination group than in the testosterone group. In conclusion, administration of testosterone propionate led to a significant elevation of oxidative stress. Vitamin E is quite an effective antioxidant which protects rabbit testis against lipid peroxidation, and, testosterone-induced lipid peroxidation could be improved by additional vitamin E treatment.     

Morphometric and ultrastructure features of the ventral prostate of rats (Rattus norvegicus) submitted to long-term nicotine treatment

The harmful effects of nicotine on male genital system fertility have been reported in experimental and clinical studies. However, its effects on prostatic cells and glandular pathogenesis remain unclear. The aim of the present study was to analyse the histological, histochemical and ultrastructural alterations, in addition to stereology, of the ventral lobe of the prostate of rats, submitted to chronic nicotine administration, as well as to establish the relationship between these changes and prostate diseases. Twelve male Wistar rats (Rattus norvegicus) were divided into two experimental groups: group I (nicotine) and group II (control). Samples of the ventral prostate were collected, processed and submitted to histological analysis, acid phosphatase histochemistry and ultrastructural analysis by transmission and scanning electron microscopies. The results showed that in the nicotine group, the secretory epithelial cells of the ventral lobe of the prostate were atrophied, and prostatic intraepithelial neoplasia occurred and reduced the expression of acid phosphatase. The disorganisation of organelles involved in the glandular secretory process, accompanied by biomembrane destructuring, was also observed. In conclusion, nicotine causes drastic alterations in the secretory epithelium of the ventral prostate, compromising its function. Furthermore, nicotine also induces premalignant lesions in the prostate gland, thus representing a risk factor in the development of prostate diseases.     

Ex vivo antioxidant effects of D-004, a lipid extract from Roystonea regia fruits, on rat prostate tissue

AIM: To investigate whether oral treatment with D-004, a lipid extract of the Cuban royal palm fruit, produces antioxidant effects in the prostate tissue of normal and testosterone (T)-treated rats. METHODS: In our first experiment, normal rats were distributed into five groups: one group treated with the vehicle and four groups treated with D-004 (100, 200, 400 or 800 mg/kg). In our second experiment, rats were randomized into five groups: a negative control group and four T-injected groups. The latter were comprised of a positive control group treated with the vehicle, and three groups treated with D-004 (200, 400 or 800 mg/kg). RESULTS: In normal rats, D-004 (100-800 mg/kg) inhibited significantly and dose-dependently iron-initiated malondialdehyde (MDA) accumulation in prostate homogenates (35.7%-80.0%) vs the controls. D-004 (200-800 mg/kg) significantly reduced baseline MDA and carbonyl groups in prostate homogenates of normal rats to approximately 80% and 50%, respectively, and totally (100%) in T-treated rats. CONCLUSION: Oral treatment with D-004 reduced MDA and carbonyl groups dose-dependently and markedly in normal and T-injected rats. These findings show that D-004 given at doses effective to prevent prostate hyperplasia also produces antioxidant effects in the prostate tissue.     

Effects of 4-MAPC,a 5α-reductase inhibitor,and cyproterone acetate on regrowth of the rat ventral prostate

Inhibitors of 5α-reductase activity cause less involution of the rat ventral prostate (VP) than does castration. Studies were conducted in adult Sprague Dawley rats to evaluate the effects of a potent 5α-reductase inhibitor, 4-MAPC, and the antiandrogen, cyproterone acetate (CA), on DNA synthesis and apoptosis. In experiment 1, VP weight fell 33%, 53%, and 83%, and DNA per ventral prostate was reduced 24%, 46%, and 71%, by 4-MAPC, CA, and castration, respectively. In experiment 2, adult rats were castrated, and the VP involuted for 7 days prior to 3 daily injections of testosterone propionate (TP; 1 mg/kg/d) ± 10 mg/kg/d of 4-MAPC or CA. ³H-thymidine incorporation into VP DNA was increased in castrated animals treated with TP, and 4-MAPC and CA reduced uptake. In experiment 3, animals were treated for 14 days with the same protocol as that used in experiment 2. VP weight was increased in all animals treated with TP when compared with castration, and was reduced by both 4-MAPC and CA. DNA in rats treated with TP was similar to that in intact animals. DNA was not reduced by 4-MAPC, but was reduced by CA. The mRNA for TRPM-2, a marker of apoptosis, was increased only in untreated castrated rats. It appears that CA has a greater inhibitory effect than 4-MAPC on DNA synthesis. A major reason why castration reduces DNA more than either 4-MAPC or CA is that neither of these agents was able to increase programmed cell death to the degree seen with castration. © 1994 Wiley-Liss, Inc.     

Effect of prolonged whole-body hyperthermia on adult male rat testes and the protective role of vitamin C and E: A histological and biochemical study

Hyperthermia (HT) is a significant risk factor for male infertility. Most researchers investigated the effect of localized and short-term HT on male fertility. This study aimed to assess the harmful impacts of prolonged and generalized HT on testicular histology and ultrastructure in rats. The possible protective effects of vitamin E (Vit E), Vit C, and their combination were also investigated. Thirty male adult Wister rats were used (5 groups). 1- control, 2- HT, 3- Vit C, 4- Vit E, and 5- Vit C + Vit E. Rats in groups 2–5 were subjected to HT (41°C), 1 hr daily for 2 weeks. HT-induced a significant decrease in body weight gain, food and water intake, and serum testosterone. HT showed a damaging effect on the testicular and coda epididymis tissue. HT significantly (p ≤ .05) produced oxidative stress (decreased serum catalase (145.49 ± 8.98), glutathione peroxidase (20.27 ± 4.46), superoxide dismutase (2.68 ± 0.54), and reduced glutathione (5.18 ± 0.33), and increased malondialdehyde (9.46 ± 1.55). Vit E alone and combined with Vit C, significantly protected the gonads against the deleterious effects of HT. The results recommended that prolonged HT of the whole body is harmful to male fertility. Prophylactic therapy with Vit E could help decrease the HT-induced male gonadal harm.     

Age dependency of androgen and estrogen effects on incorporation of (3H)-thymidine by rat prostates in organ culture

Organ culture of the rat ventral prostate has been evaluated as a model for studying the biological effects of androgen agonists, androgen antagonists, and estrogens. Explants were cultured for up to 8 days, and incorporation of (3H)-thymidine and (3H)-uridine by the explants was measured. Dihydrotestosterone (DHT) increased the incorporation of (3H)-thymidine/microgram DNA when compared with the untreated controls at 4 days, P less than .05; and at 6 days, P less than .01. Enhanced uptake in explants from 6 to 8-week old rats also was observed with 10 nM estradiol (P less than .05) and 10 nM cyproterone acetate (P less than .02). DHT (10 nM) caused greater enhancement of uptake in explants from 3-week-old rats than in explants from 6- or 12-week-old rats. In contrast, estradiol (E2) increased incorporation only in prostates from the 6-week-old rats. Since both DHT and E2 can enhance (3H)-thymidine uptake even though they are associated with strikingly different effects on prostate morphology, it suggests that their effects on (3H)-thymidine incorporation are mediated by different cells.