Effect of nonylphenol on steroidogenesis of rat Leydig cells

Nonylphenol is the primary final biodegradation product of nonylphenol polyethoxylate (NPE), a non-ionic surfactant that is frequently incorporated into pesticide and detergent formulation. Recent researchers have hypothesized that environmental/ occupational exposure to nonylphenol poses adverse effects on reproductive system of humans and wildlife species. During our study, in vivo and in vitro experiments were performed to examine the effect of nonylphenol on testosterone biosynthesis of rat Leydig cells. In experiment in vivo, serum testosterone (T) as well as luteinizing hormone (LH) levels were detected after animals had been treated with different doses (0 mg/kg/day, 125 mg/kg/day, and 250 mg/kg/day) of nonylphenol for 50 days by gavage, and the final result revealed that testosterone level dramatically declined at the dose of 250 mg/kg/day, while LH level ascended at the dose of 125 mg/kg/day and 250 mg/kg/day. In experiment in vitro, primary cultured Leydig cells were exposed to nonylphenol for 48 h, including low concentrations (0 mg/L, 0.0011 mg/L, 0.0033 mg/L, 0.0055 mg/L, 0.011 mg/L, 0.022 mg/L) and higher concentrations (0.11 mg/L, 0.55 mg/L, 1.1 mg/L, 1.65 mg/L, 2.2 mg/L, 2.75 mg/L, 3.3 mg/L, 5.5 mg/L). Increase of testosterone levels was observed at low concentrations of nonylphenol while reduction was detected at higher concentrations.     

Reproductive effects of tris(4-chlorophenyl)methanol in the rat.

Tris(4-chlorophenyl)methanol (TCPM) is a global contaminant of unknown origin that is structurally related to the endocrine modulating pesticides 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and Dicofol. Therefore, the potential reproductive toxic effects of TCPM were investigated in sexually mature male Sprague Dawley rats (n = 20) treated with 1.0, 10.0 or 100 ppm of TCPM mixed in the diet for 28 days. The calculated TCPM intake was 0.0, 0.1, 1.2 and 12.4 mg/kg/day, respectively. Serum concentrations of follicle stimulating hormone (FSH) in terminal blood samples were significantly (P < 0.02) elevated in the highest dose group compared to the controls. In contrast, dietary exposure to TCPM had no effect on circulating levels of luteinizing hormone (LH), testosterone (T) and the T/LH ratio. Incubation of MCF-7 cells with increasing concentrations of TCPM failed to either induce proliferation or to block the proliferative effect induced by estradiol indicating that TCPM is neither estrogenic or anti-estrogenic. Relative binding affinity studies using androgen receptors from the prostate revealed that TCPM has a binding affinity comparable to 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), the principle metabolite of DDT. In addition, the calculated Ki (0.62 microM) for TCPM is lower than the reported Ki's for the antiandrogenic pesticides p,p'-DDE and vinclozolin. Although TCPM binds with the androgen receptor in vitro, the absence of both an effect on serum T levels and morphological changes in the testis suggests that the mechanism of action for elevated FSH levels seen in vivo may not involve an antiandrogenic effect of TCPM at the dose level used in this study. The no adverse effect level for reproductive effects of TCPM is 10 ppm which is equivalent to a calculated intake of 1.2 mg/kg/day.     

Teratologic assessment of maleic hydrazide and daminozide,and formulations of ethoxyquin,thiabendazole and naled in rats

Abstract

Teratogenicity studies were conducted in rats treated orally from days 6–15 of gestation with single daily doses of 400–1600 mg/kg of maleic hydrazide, 300–1000 mg/kg daminozide, 125–500 mg/kg ethoxyquin or thiabendazole, or 25–100 mg/kg naled. Dams were killed on the 22nd day of gestation, and fetuses were evaluated by routine teratologic methods. No adverse effect was related to any treatment other than an increased incidence of anomalous fetuses at the highest dose (500 mg/kg) of thiabendazole.     

Effect of chronic exposure to cadmium on hepatic drug metabolism

Abstract

In an attempt to examine the chronic effect of low levels of cadmium on hepatic drug‐metabolizing enzyme system, an experiment was carried out in which growing male rats were given 0, 5, 10, and 2 0 ppm of cadmium in drinking water for a period of 8 weeks. An ip administration of a hypnotic dose of pentobarbital to the cadmium‐treated and the control rats 2 4 hr following the termination of the experiment exhibited that there was no significant difference in the drug metabolism in control and any of the treated groups. Next, liver microsomes were isolated from animals in all groups to study their ability to metabolize drugs in vitro. The results indicated that the activity of benzphetamine N‐demethylase and aniline hydroxylase, and the concentration of microsomal cytochrome P‐450 were almost identical in the control and treated groups. On the other hand, a single ip dose of cadmium (2 mg/kg) caused significant decrease in the in vivo and in vitro microsomal drug metabolism. These results suggest that although a single ip dose of cadmium (2 mg/kg) causes significant inhibition of drug metabolism, chronic exposure to cadmium up to 2 0 ppm in drinking water over a period of 8 weeks is unlikely to affect hepatic drug metabolism.     

Effect of manganese on the concentration of amino acids in different regions of the rat brain

Abstract

The present study was designed to determine if chronic exposure of weanlings and adult rats to Mn produces significant alterations in amino acid concentrations in different regions of the rat brain. Weanling (30 day old) and adult (90 day old) male rats were exposed to 10 and 20 mg Mn/kg body weight per day, by gavage, for 30 days. Forty‐ eight hours after the last dose, animals were sacrificed by decapitation and brains were dissected into different regions to determine the concentration of amino acids by HPLC/EC. A dose dependent decrease in body weight gain was found in the adult, but not in the weanling rats. Significant increases occurred in concentrations of aspartate, glutamate, glutamine, taurine and y‐aminobutyric acid (GABA) in the cerebellum of the adult rats dosed with 20 mg/kg per day, Mn. A significant decrease in the concentration of glutamine was observed in caudate nucleus and hippocampus of weanling rats dosed with 10 mg/kg, Mn. These data suggest that chronic Mn exposure can produce a decrease in body weight gain in adult rats and alterations in amino acids in different regions of weanling and adult rat brains.     

A teratological assessment of four trihalomethanes in the rat

Abstract

Four trihalomethanes were administered by gavage to Sprague‐Dawley rats from day 6 to day 15 of gestation. Chloroform (Ch) was administered at levels of 100, 200 and 400 mg/kg and bromoform (Br), bromodichloromethane (BDCM) and chlorodibromomethane (CDBM) were administered at levels of 50, 100 or 200 mg/kg/day. A separate control was used for each compound. Maternal weight gain was depressed in all groups receiving Ch and at the highest dose levels of BDCM and CDBM. Ch administration caused decreased maternal hemoglobin and hematocrit values at all dose levels and also produced increased serum inorganic phosphorus and cholesterol at the highest dose. Liver enlagement was observed at all dose levels of Ch but in no other treatment groups. Evidence of a fetotoxic response was observed with Ch, CDBM and Br but not BDCM. No dose‐related histopathological changes were observed in either mothers or fetuses as a result of treatment. None of the chemicals tested produced any teratogenic effects.     

Teratologic assessment of maleic hydrazide and daminozide, and formulations of ethoxyquin, thiabendazole and naled in rats

Teratogenicity studies were conducted in rats treated orally from days 6-15 of gestation with single daily doses of 400-1600 mg/kg of maleic hydrazide, 300-1000 mg/kg daminozide, 125-500 mg/kg ethoxyquin or thiabendazole, or 25-100 mg/kg naled. Dams were killed on the 22nd day of gestation, and fetuses were evaluated by routine teratologic methods. No adverse effect was related to any treatment other than an increased incidence of anomalous fetuses at the highest dose (500 mg/kg) of thiabendazole.     

Effect of long-term dietary lead exposure on some maturation and reproductive parameters of a female Prussian carp (Carassius gibelio B.)

Lead is reported to be an endocrine disruptor. In the current study, we exposed female Prussian carp to artificial feed, supplemented with five doses of dietary Pb (0, 1 (control), 8, 13, 24, and 49 mg/kg) over either a 24-month period or a 12-month period, followed by further 12 months where the fish were fed the control diet. Periodically, oocyte maturation, gonadosomatic index (GSI), ability to secret luteinizing hormone (LH) as well as gonad Pb concentrations were measured. It was found that the reproductive system of the female Prussian carp is not indifferent to chronic exposure to lead. The negative effect was manifested by a decrease in the GSI after 12 months despite the fact that a higher proportion of oocytes at more advanced maturity stages were concurrently observed. After 12 months of exposure, the effect on LH secretion varied according to the dose. In the group exposed to the lowest dose (8 mg/kg), LH decreased spontaneously, and in the groups exposed to the highest two doses (24 and 48 mg/kg), a significantly higher LHRH-A-stimulated LH secretion was observed. After 24 months of lead exposure, the effects on oocyte maturation and size and on GSI values were not pronounced. Analysis of the effect of lead exposure on LH secretion showed that the relationships were similar to those observed after 12 months but nonsignificant. During chronic a 24-month period exposure to Pb, Prussian carp female appears to acclimate to Pb doses used in the experiment. After 12 months of exposure and 12 months of depuration, the levels of spontaneous and stimulated LH secretion observed in all the groups were similar to the control, which is evidence that depuration eliminates the previously observed effects of exposure to lead. Lead is easily accumulated in the ovary, reaching a fivefold higher level (0.8 mg/kg tissue) compared to the control (0.15 mg/kg tissue), but after discontinuation of exposure, this organ is quickly depurated. The results indicate that environmental Pb can be a potent endocrine disruptor affecting ovarian steroidogenesis, gametogenesis, and ovulation, which may lead to adverse impacts on fish reproduction and population density and that female Prussian carp become resistant to the negative effects of lead with advancing age, and their organs cope by reaching a state of homeostasis.     

Priority organic pollutant assessment of sludges for agricultural purposes

A comprehensive characterization of five of the seven priority organic pollutants listed in the draft of the "Working document on sludge" [EU, 2000. Working Document on Sludge 3rd Draft. Unpublished, 19 p] has been carried out during 2001-2003 in sludge samples from Catalonia (NE Spain). One hundred and thirty-nine samples belonging to 20 Waste Water Treatment Plants (WWTPs), seven sludge treatment (thermal drying) and three composting sludge plants were taken in order to determine the concentration of polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs), di-2-(ethyl-hexyl)-phthalate (DEHP), nonylphenol and nonylphenol ethoxylates with one or two ethoxy groups (NPE), polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). PCDD/F concentrations were in general lower than the 100 ng I-TEQ/kg limit suggested in the above-mentioned document. In the same way, 98.5% for PCBs, 97% for PAH and 92.8% for DEHP of the samples presented concentrations lower than 0.8 mg/kg dm, 6 mg/kg dm and 100 mg/kg dm, respectively. In contrast, the vast majority of samples contained NPE concentrations much higher than 50mg/kg dm limit. The values ranged from 14.3 to 3150 mg/kg dm (median value=286.6 mg/kg) being composted sludge samples the less contaminated ones (17.9-363.4 mg/kg dm; median value=89.3 mg/kg). Special attention should be paid to the Catalan sludge NPE contamination owing to the high levels detected.     

Impact of molybdenum nanoparticles on survival,activity of enzymes,and chemical elements in <Emphasis Type="Italic">Eisenia fetida</Emphasis> using test on artificial substrata

The influence of molybdenum oxide nanoparticles (MoO₃) on the growth and survival of Eisenia fetida was established. The activity of antioxidant enzymes and changes in concentration of molybdenum in the body of E. fetida were determined. The degree of bacterial bioluminescence inhibition in extracts of substrates and worm was studied using luminescent strain Escherichia coli K12 TG1. The enzymatic activity of substrates before and after exposure with nanoparticles and worms was assessed. Nanoparticles have concentrations of 10, 40, and 500 mg/kg of dry matter, and substrata are made of artificial soil (substrate A) and microcrystalline cellulose (substrate B). Spherical nanoparticles MoO₃, yellow in color, with size 92?±?0.3 nm, Z-potential 42?±?0.52 mV, molybdenum content 99.8 mass/%, and specific area 12 m²/g were used in the study. A significant decrease by 23.3 % in weight was registered (for MoO₃ NPs at 500 mg/kg) on substrate A (p?≤?0.05). On substrate B, the maximum decrease in weight by 20.5, 33.3, and 16.9 % (p?≤?0.05) was registered at a dose of 10, 40, and 500 mg/kg, respectively; mortality was from 6.6 to 73 %. After the assessment of bacterial bioluminescence inhibition in substrates A and B (extracts) and before worms were put, the toxicity of substrates was established at doses of 40 and 500 mg/kg, expressed in inhibitory concentration (IC) 30 and IC 50 values. Comparatively, on days 7 and 14, after exposure in the presence of E. fetida, no inhibition of bioluminescence was registered in extracts of substrates A and B, indicating the reduction in toxicity of substrates. The initial content of molybdenum in E. fetida was 0.9?±?0.018 mg/kg of dry matter. The degree of molybdenum accumulation in worm tissue was dependent on the dose and substrate quality. In particular, 2–7 mg/kg of molybdenum accumulated from substrate A, while up to 15 kg/kg of molybdenum accumulated from substrate B (day 7). Molybdenum concentration decreased by 64.8 and 57.4 % at doses 40 and 500 mg/kg, respectively, on day 14. The reaction of antioxidant enzymes was shown in an insignificant increase of glutathione reductase (GSR) and catalase (CAT) at concentrations of 10 and 40 mg/kg in substrate A, followed by the subsequent reduction of their activity at the dose of 500 mg/kg MoO₃. The activity of GSR in substrate B against the presence of MoO₃ nanoparticles decreased, with significant difference of 33.5 % (p?≤?0.05) at the dose of 500 mg/kg compared with untreated soil. In experiments with substrate A, an increase of catalase activity was registered for the control sample. The presence of MoO₃ nanoparticles at the concentration of 10 mg/kg in the environment promoted enzymatic activity on days 7 and 14, respectively. A further increase of nanoparticle concentration resulted in the decrease of catalase activity with a minimum value at the concentration of MoO₃ of 500 mg/kg. In the experiment with substrate B at the concentration of MoO₃ nanoparticles of 40 mg/kg, enzymatic activity increases on day 7 of exposure. However, the stimulating effect of nanoparticles stops by day 14 of the experiment and further catalase activity is dose dependent with the smallest value in the experiment with MoO₃ having the concentration of 500 mg/kg.     

Determination of nonylphenol ethoxylates and octylphenol ethoxylates in environmental samples using 13C-labeled surrogate compounds

Alkylphenol polyethoxylates (APEOs) have been widely used as nonionic surfactants in a variety of industrial and commercial products. Typical compounds are nonylphenol polyethoxylates (NPEOs) and octylphenol polyethoxylates (OPEOs), which serve as precursors to nonylphenol (NP) and octylphenol (OP), respectively. NP and 4-t-OP are known to have endocrine disrupting effects on fish (medaka, Oryzias latipes), so it is important to know the concentrations of APEOs in the environment. Because the analytical characteristics of these compounds depend on the length of the ethoxy chain, it is necessary to use appropriate compounds as internal standards or surrogates. We synthesized two 13C-labeled surrogate compounds and used these compounds as internal standards to determine NPEOs and OPEOs by high-performance liquid chromatography (LC)-mass spectrometry. Method detection limits were 0.015 microg/L for NP (2)EO to 0.037 microg/L for NP(12)EO, and 0.011 microg/L for OP(3,6)EO to 0.024 microg/L for OP (4)EO. NPEO concentrations in water from a sewage treatment plant were less than 0.05-0.52 microg/L for final effluent and 1.2-15 microg/L for influent. OPEO concentrations were less than 0.05-0.15 microg/L for the final effluent and less than 0.05-1.1 microg/L for influent.     

Effect of chronic exposure to cadmium on hepatic drug metabolism

In an attempt to examine the chronic effect of low levels of cadmium on hepatic drug-metabolizing enzyme system, an experiment was carried out in which growing male rats were given 0, 5, 10, and 20 ppm of cadmium in drinking water for a period of 8 weeks. An ip administration of a hypnotic dose of pentobarbital to the cadmium-treated and the control rats 24 hr following the termination of the experiment exhibited that there was no significant difference in the drug metabolism in control and any of the treated groups. Next, liver microsomes were isolated from animals in all groups to study their ability to metabolize drugs in vitro. The results indicated that the activity of benzphetamine N-demethylase and aniline hydroxylase, and the concentration of microsomal cytochrome P-450 were almost identical in the control and treated groups. On the other hand, a single ip dose of cadmium (2 mg/kg) caused significant decrease in the vivo and in vitro microsomal drug metabolism. These results suggest that although a single ip dose of cadmium (2 mg/kg) causes significant inhibition of drug metabolism, chronic exposure to cadmium up to 20 ppm in drinking water over a period of 8 weeks is unlikely to affect hepatic drug metabolism.     

Toxic effects of 2,4‐D herbicide on fish

Abstract

Acute and subacute 2,4‐D toxicity to carp (Cyprinus carpio L.) were investigated. Acute toxicity (LC‐ 50) was investigated in semi‐static test during a 24, 48, and 96‐ hours exposition. Subacute toxicity was investigated by exposing fish to different 2,4,‐D concentrations (150, 200, and 250 mg/L) for 14 days. Biochemical and morphological changes in certain organs and tissues were investigated.

LC‐ 50 values at 24 hours exposure was 310.0 mg/L, 295.0 mg/L for 48 hours, and 270.0 mg/L for 96 hours exposure.

Subacute toxicity tests show that 2,4‐D induce changes in the enzyme activities (AP, GOT, GPT) and morphological changes in the gills, liver and kidneys, but changes are of limited biological importance.     

Ochratoxin A and Penicillic acid interaction in mice

Abstract

Penicillic Acid (PA) and Ochratoxin A (OA) are toxic fungal metabolites that are synergistic in combination. This interaction was investigated using mice which were dosed orally as follows: control, none; solvent control, 0.2 ml bicarbonate buffer; PA, 40 mg/kg; OA, 10 mg/kg and combination, 40 mg/kg PA + 10 mg/kg OA. The only significant histopathologic change observed was an acute multifocal toxic tubular nephrosis which appeared most severe in the combination‐treated mice killed on day 10. While the combination group had a death rate of 20% (5/25), no deaths occurred in the other treatment groups. The increased death rate and the extensive nephrotoxic findings in the combination group indicate a toxic interaction between OA and PA at sub‐lethal dose levels and is consistent with a renal site of action.     

Effects of acute postnatal exposure to 3,3',4,4'-tetrachlorobiphenyl on sperm function and hormone levels in adult rats

Polychlorinated biphenyls (PCBs) are considered potential endocrine disruptors due to their ability to act as estrogens, antiestrogens and goitrogens. The aim of this study is to ascertain whether acute postnatal treatment with 3,3',4,4'-tetrachlorobiphenyl (CB 77) affects sperm function and hormone levels in adult rats. Male Sprague-Dawley rats received CB 77 by ip injection of 2 or 20 mg/kg at day 21 and sacrificed at day 112. At day 112, right and left testis weights were significantly increased, whereas sperm count, motility, total motile sperm count, curvilinear velocity, average path velocity, straight-line velocity, and beat-cross frequency for motile sperm were significantly decreased in rats treated with 20 mg/kg CB 77. Sperm-oocyte penetration rate was significantly reduced in rats treated with either 2 or 20 mg/kg CB 77. There was high sperm acrosome reaction rate (ARR) in the 20 mg/kg CB 77-treated rats. There was a significant increase in thyroid-stimulating hormone level in the 20 mg/kg CB 77 group. However, no changes were seen in serum testosterone, thyroid hormones, or prolactin concentrations at day 112. In summary, this study showed that postnatal exposure to CB 77 might affect spermatogenesis, motility, ARR, and ability of fertilizing oocytes in mature rats. These results suggest that the sperm functions may be more susceptible or adapt less readily than the thyroid functions to endocrine disruption caused by dioxin-like PCB congeners.     

Neurotoxic effects of leptophos (PhosvelR) in chickens and rats following chronic low-level feeding.

Leptophos (O-[4-bromo-2,5 dichlorophenyl] O-methyl phenylphosphonothioate) (PhosvelR) was administered orally to chickens and rats in doses of 0.5 and 5.0 mg/kg/day for 26 weeks. Hens fed 5.0 mg/kg, except one, showed ataxia and became paralysed in the legs at varying times from 8 to 19 weeks. A fifth hen showed ataxia early in the experiment but recovered fully for the remainder of the experiment. Rats fed both doses and chickens fed 0.5 mg/kg showed no signs of delayed neurotoxicity. All hens fed 5.0 mg/kg stopped laying by about the third week. Animals of both species fed 5.0 mg/kg either lost weight (chickens) or gained less weight (rats) than the others. Erythrocyte acetylcholinesterase (AChE) of the chickens given both doses was significantly depressed at first, then increased, and later dropped to control levels. AChE of rats fed 0.5 mg/kg was significantly inhibited but soon recovered to within control levels. On the other hand, the AChE of rats fed 5.0 mg/kg was inhibited throughout the experiment. Plasma cholinesterase (ChE) of both species was first inhibited and then recovered erratically for both insecticide concentrations. Histological alterations in the spinal cord of paralysed hens included axon and myelin degeneration in the ventral, lateral and posterior columns. In the paralysed hens, 79% of the neurotoxic esterase in the brain were inhibited, whereas in the non-paralysed hens (including the one non-paralysed hen receiving 5.0 mg/kg/day) and all rats only about half as much was inhibited.     

Specific resistance to filtration of biomass from membrane bioreactor reactor and activated sludge: effects of exocellular polymeric substances and dispersed microorganisms.

This study investigates the effect of dispersed microorganisms and exocellular polymeric substances on biomass dewaterability. Specific resistance to filtration (SRF) was measured for biomass from a membrane bioreactor and a completely mixed activated sludge system. Both laboratory-scale reactors were fed with synthetic wastewater and operated at a high food-to-microorganism ratio (F/M) (1 to 11 kilograms chemical oxygen demand per kilogram mixed liquor volatile suspended solids per day [kgCOD/(kg MLVSS.d)]) and short solids retention times (0.25 to 5 d). The SRF values were affected by strong interactions of three parameters: (1) the mixed liquor suspended solids concentration, (2) the amount of dispersed microorganisms, and (3) the exocellular polymeric substances (EPS) concentration. At F/M smaller than 2 kg COD/(kg MLSS.d) and mixed liquor suspended solids (MLSS) concentration higher than 2000 mg/L, increasing amount of dispersed microorganisms in the biomass yielded higher SRF values. However, at high F/M (> 5 kg COD/kg MLSS.d) and low MLSS concentrations (< 600 mg/L), lower EPS concentrations resulted in slightly smaller SRF values, even though the amount of dispersed microorganisms in the biomass was much higher. Thus, at low MLSS concentrations, EPS concentrations rather than the amount of dispersed microorganisms tend to control SRF.     

α-Amylase and α-glucosidase inhibitor effects and pancreatic response to diabetes mellitus on Wistar rats of Ephedra alata areal part decoction with immunohistochemical analyses

Ephedra alata, known as a medicinal plant in China, was used in this study as aqueous extract from aerial parts, for diabetes mellitus treatment. This study was carried out on two parts, in vitro, we tested the effect of the studied extract on the inhibition of α-glucosidase and α-amylase activities, and in vivo on Wistar male rats receiving alloxan intraperitoneally at a rate of 125 mg/kg. Extract (100, 200, and 300 mg/kg of body weight) was administrated for 28 days by oral gavage. Blood glucose, amylase, lipase, and lipid profile level were determined. Oxidative stress was evaluated by enzymatic activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), and by estimation of lipid peroxidation and protein carbonyl (PC) level. Histopathological changes in pancreas were investigated under photonic microscopy using immunohistochemical procedure. Our findings showed that aqueous extract inhibited in vitro both α-glucosidase and α-amylase activities and its use in vivo at 300 mg/kg of body weight restored pancreas weight and weight gain, ameliorated significantly (p ? 0.05) biochemical parameters; it prevented the increase in lipid and protein oxidation and the decrease in enzymatic and non-enzymatic defense system. Histological study of treated animals showed a comparable healed regeneration of beta cells.

     

Effect of Isoflavones on Reproductive Performance,Testosterone Levels,Lipid Peroxidation,and Seminal Plasma Biochemistry of Male Rabbits

Abstract

The objective of this study was to determine the effect of either 2.5 mg/kg Body Weight or 5 mg/kg Body Weight (BW) doses of isoflavones on semen quality, testosterone levels, lipid peroxidation and semen biochemistry of male New Zealand White rabbits. Animals were given both 2.5 mg/kg BW and 5 mg/kg BW doses of isoflavones. The tested doses were given to rabbits orally every other day for 13 weeks. Treatment with isoflavones caused an increase (p < 0.05) in libido (by decreasing the reaction time), sperm concentration, sperm motility (%), total motile sperm per ejaculate (TMS), packed sperm volume (PSV), total functional sperm fraction (TFSF), total sperm output, initial fructose concentration and normal sperm, while dead sperm was reduced compared to control animals. On the other hand, ejaculate volume, initial hydrogen ion concentration (pH) and plasma testosterone levels did not change in treated animals with both doses of isoflavones as compared to control. Concentrations of thiobarbituric acid-reactive substances (TBARS), total lipids, and low density lipoprotein were significantly (p < 0.05) reduced in seminal plasma of rabbits treated with either 2.5 mg/kg BW or 5 mg/kg BW doses of isoflavones. While, the activities of glutathione S-transferase (GST), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), acid phosphatase (AcP), and alkaline phosphatase (AlP) were significantly (p < 0.05) increased in seminal plasma of treated animals. Also, total cholesterol, percentage cholesterol (out of total lipids), and high density lipoprotein were significantly (p < 0.05) increased, while triglyceride did not change in seminal plasma of treated animals. Supplementation at either level of isoflavones did not cause changes in live body weight (LBW), dry matter intake (DMI), and relative weights of testes and epididymis. The present results showed that either 2.5 mg/kg BW or 5 mg/kg BW doses of isoflavones caused an improvement of some semen characteristics and did not have negative effects on male fertility.     

Effect of manganese on the concentration of amino acids in different regions of the rat brain

The present study was designed to determine if chronic exposure of weanlings and adult rats to Mn produces significant alterations in amino acid concentrations in different regions of the rat brain. Weanling (30 day old) and adult (90 day old) male rats were exposed to 10 and 20 mg Mn/kg body weight per day, by gavage, for 30 days. Forty-eight hours after the last dose, animals were sacrificed by decapitation and brains were dissected into different regions to determine the concentration of amino acids by HPLC/EC. A dose dependent decrease in body weight gain was found in the adult, but not in the weanling rats. Significant increases occurred in concentrations of aspartate, glutamate, glutamine, taurine and gamma-aminobutyric acid (GABA) in the cerebellum of the adult rats dosed with 20 mg/kg per day, Mn. A significant decrease in the concentration of glutamine was observed in caudate nucleus and hippocampus of weanling rats dosed with 10 mg/kg, Mn. These data suggest that chronic Mn exposure can produce a decrease in body weight gain in adult rats and alterations in amino acids in different regions of weanling and adult rat brains.