RESUMEN
We have previously demonstrated that the sub-chronic administration of low doses of Toc or α-Toc, glyphosate and zineb to rats (i.p. 1/250 LD50, three times a week for 5 weeks) provoked severe oxidative stress (OS) in testicles. These effects were also reflected in plasma. Lipoic acid (LA) and α-tocopherol are considered as antioxidants due to their ability to neutralize reactive oxygenated species (ROS) and reset endogenous antioxidant levels. To investigate the possible protective effect on reproductive function, LA and Toc (i.p. 25, 50 and 100mg/kg) were administered simultaneously with the pesticide mixture (PM) for 5 weeks. Both drugs prevented OS and the damage to proteins and lipids caused by PM in a dose-dependent manner. The PM-induced increase levels of prostaglandins E2 and F2α was completely restored by LA but not by Toc. Similarly, only LA was able to restore the inhibition of testosterone production, the decrease of 3ß- and 17ß-hydroxysteroid dehydrogenases activities, and the elevation of gonatropins (FSH and LH) levels produced by PM. Furthermore, LA was more efficient than Toc in normalizing the histological alterations produced by PM administration, suggesting that pesticides act though other mechanisms that generate oxidative stress. In our experimental model LA displayed a higher protective role against pesticide-induced damage than that observed by Toc administration. Our results suggest that LA administration is a promising therapeutic strategy for coping with disorders suspected to be caused by OS generators - such as pesticides - in male reproductive system.
Asunto(s)
Antioxidantes/farmacología , Contaminantes Ambientales/toxicidad , Plaguicidas/toxicidad , Testículo/efectos de los fármacos , Ácido Tióctico/farmacología , Tocoferoles/farmacología , Animales , Hormonas Esteroides Gonadales/sangre , Masculino , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismoRESUMEN
The mechanism involved in the inhibition of testosterone (Te) biosynthesis after a sub-chronic exposure to low doses of dimethoate (D) was studied in rat interstitial cells (IC). Expression of COX-2 in IC isolated from D-treated rats increased by 44% over C data, while transcription of StAR decreased by approx. 50% and the expression of this protein was diminished by approximately 40%. PGE(2) and PGF(2alpha) were increased by 61 and 78%, respectively. Te concentration decreased by 49% in IC homogenates. Concomitantly, plasma concentration of LH and FSH both increased. Araquidonate (ARA) and C(22) fatty acyl chains in phospholipids from IC mitochondrial fraction decreased by approx. 30% after D treatment. Protein carbonyls, lipoperoxides and nitrite content increased while alpha-tocopherol and the antioxidant capacity of the soluble cellular fraction decreased significantly. Stimulation with h-CG 10 nM overnight failed to overcome the inhibition caused by D on both Te biosynthesis and 3beta- and 17beta-hydroxysteroid dehydrogenases. Decreased Te biosynthesis may be attributed to (1) inhibition of StAR protein activity due to the stimulation of COX-2 and the overproduction of PGF(2alpha), (2) decreased stimulatory effect of ARA on StAR with a subsequent reduction in the availability of CHO for the androgenic pathway, and/or (3) indirect inhibition of steroidogenic enzymes by a lower transcriptional rate caused by elevated PGF(2alpha). Rofecoxib administration prevents the deleterious effect(s) exerted by D.
Asunto(s)
Dimetoato/farmacología , Células Intersticiales del Testículo/efectos de los fármacos , Lípidos/farmacología , Testosterona/biosíntesis , Animales , Peso Corporal/efectos de los fármacos , Células Cultivadas , Inhibidores de la Colinesterasa/farmacología , Ciclooxigenasa 2/genética , Ciclooxigenasa 2/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Crecimiento y Desarrollo/efectos de los fármacos , Insecticidas/farmacología , Células Intersticiales del Testículo/metabolismo , Masculino , Estrés Oxidativo/efectos de los fármacos , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Ratas , Ratas WistarRESUMEN
The aim of this study was to examine the influence of dietary fat on lipid composition, as well as on the steroidogenic function of interstitial cells isolated from Wistar rats that had been fed semi-synthetic diets containing four different commercial oils (S soybean, O olive, C coconut, and G grape seed). Steroidogenic enzyme activities, lipid composition, and androgen production were measured in testicular interstitial cells. Lipid analysis included measurement of the contents of major lipid subclasses (neutral lipids, polar lipids, free and esterified cholesterol), as well as principal polar and neutral lipid fatty acyl compositions. Significant differences in lipid composition were observed among the groups, most of them reflecting the specific fatty acyl composition of the diet tested. Testosterone concentration was higher in O and C groups compared with S or G. In agreement with this observation, the activity of both key enzymes involved in testosterone biosynthesis (3-beta-HSD and 17-beta-HSD) was higher in O and C groups with significant differences between them (O > C). A significant negative correlation was found between cellular testosterone production and cellular cholesterol ester content. Additionally, testosterone concentration directly correlated with cholesterol levels. We conclude that dietary oils qualitatively and quantitatively modified the lipid composition of interstitial cells, producing either a direct or indirect regulatory effect on testicular steroidogenic function.
Asunto(s)
Grasas Insaturadas en la Dieta/farmacología , Lípidos/química , Testículo/efectos de los fármacos , Testosterona/biosíntesis , 17-Hidroxiesteroide Deshidrogenasas/metabolismo , 3-Hidroxiesteroide Deshidrogenasas/metabolismo , Animales , Cromatografía Líquida de Alta Presión , Masculino , Ratas , Ratas Wistar , Testículo/enzimología , Testículo/metabolismoRESUMEN
OBJECTIVE: The present study explored the effect of dietary oils on lipid composition, antioxidant status, and the activity of the main steroidogenic enzymes in the testis. METHODS: Forty Wistar rats were randomly assigned to one of four groups (n = 10) fed for 60 d on the same basal diet plus different lipid sources as commercial oils: soybean, olive, coconut, or grapeseed. After sacrifice, testicular lipids and fatty acid composition, free radical biomarkers, antioxidant levels, hormones, and steroidogenic enzymes were determined. RESULTS: The lipid composition of diets produced significant changes in neutral/phospholipids, free/esterified cholesterol, and plasmalogen proportion. Fatty acid patterns of these lipids were also strongly modified, influencing the double bond index. We also found a close correlation between the type of diet and the generation of free radicals. The oxidative stress in testes was higher with the grapeseed oil-supplemented diet and decreased with the other diets in this order: soybean oil > olive oil > coconut oil. Animals fed with the olive oil and coconut oil diets showed the highest testicular levels of antioxidants in addition to significantly high levels of testosterone and 3beta- or 17beta-hydroxysteroid dehydrogenase enzymes. CONCLUSION: Different oils in the diets strongly modified the homeostasis of the testicular antioxidant defense system and, in consequence, affected steroidogenic function, showing a clear correlation with the damage induced. According to our results, an appropriate mixture of olive and soybean oils could be a healthy recommendation.
Asunto(s)
Grasas de la Dieta/farmacología , Estrés Oxidativo/efectos de los fármacos , Testículo/efectos de los fármacos , Testículo/metabolismo , Testosterona/metabolismo , 17-Hidroxiesteroide Deshidrogenasas/metabolismo , 3-Hidroxiesteroide Deshidrogenasas/metabolismo , Animales , Aceite de Coco , Homeostasis/efectos de los fármacos , Homeostasis/fisiología , Masculino , Aceite de Oliva , Oxidación-Reducción , Aceites de Plantas/farmacología , Distribución Aleatoria , Ratas , Ratas Wistar , Aceite de Soja/farmacología , Testículo/enzimologíaRESUMEN
The aetiology of varicocele is multifactorial although hormonal imbalance and oxidative stress play a key role in the progression of illness. No conclusive evidence has been presented previously, describing the changes in these two factors and the evolution of patients after varicocelectomy. Semen characteristics and hormonal profile were analysed in 36 infertile men with unilateral left varicocele and 33 age-paired controls (proved to be fertile men), after careful inclusion/exclusion selection criteria. Liposoluble and hydrosoluble antioxidants, oligoelements and enzyme activities of the antioxidant defence system were also determined in plasma and erythrocyte from antecubital and spermatic veins, and in spermatozoa. Data were compared between groups at different times before and after varicocelectomy. Decreased levels of liposoluble and hydrosoluble antioxidants and increased activities of the antioxidant defence system enzymes were observed in patients compared with controls. Varicocelectomy normalized this condition at different post-surgical times. Levels of Zn and Se in seminal plasma, protein carbonyls and fragmented DNA remained elevated up to 1 month after surgery. Luteinizing and follicle stimulating hormone concentrations exhibited a biphasic behaviour while testosterone was diminished in patients but normalized soon after varicocelectomy. The results clearly demonstrate the link between the antioxidant defence system, hormonal status and semen characteristics along the post-varicocelectomy period. We suggest that oxidative biomarkers may be appropriate in controlling the evolution of post-varicocelectomy patients, and antioxidant supplementation may improve the clinical condition of infertile men with varicocele.
Asunto(s)
Antioxidantes/metabolismo , Hormonas/sangre , Infertilidad Masculina/etiología , Estrés Oxidativo , Semen/metabolismo , Varicocele/metabolismo , Procedimientos Quirúrgicos Vasculares , Adulto , Argentina , Biomarcadores/sangre , Estudios de Casos y Controles , Fragmentación del ADN , Hormona Folículo Estimulante/sangre , Humanos , Infertilidad Masculina/sangre , Infertilidad Masculina/enzimología , Infertilidad Masculina/metabolismo , Infertilidad Masculina/cirugía , Hormona Luteinizante/sangre , Masculino , Carbonilación Proteica , Semen/enzimología , Proteínas de Plasma Seminal/metabolismo , Espermatozoides/metabolismo , Testosterona/sangre , Factores de Tiempo , Resultado del Tratamiento , Varicocele/sangre , Varicocele/complicaciones , Varicocele/enzimología , Varicocele/cirugíaRESUMEN
Primary culture is a suitable system to study lipid metabolism and polyunsaturated fatty acid biosynthesis. Sertoli cell-enriched preparations were used to determine the fatty acid composition after 5 and 7 days in culture (serum free) as well as the uptake and metabolism of [1-14C]eicosa-8,11,14-trienoic acid. The addition of unlabeled linoleic acid (0.2 and 2.0 microg/ml) was also evaluated. Fatty acid methyl esters derived from cellular lipids were analyzed by gas liquid chromatography and radiochromatography. After 5 days in culture, cells had significantly less 18:2, 20:4, 22:5 and 24:5 and more 18:3, 20:3, 22:4 and 24:4 n-6 fatty acids than non-cultured cells. On day 7, an additional increment in 22:4 n-6 and a decrease in linoleic, gamma-linoleic and 24:4 n-6 fatty acids were observed. The presence of linoleic acid (low dose) produced a significant decrease in saturated and monounsaturated acids and an increase in 18:2, 20:4 and 22:5 n-6 fatty acids. At a high concentration almost all fatty acids belonging to 18:2 n-6 increased significantly. The drop in 20:4 n-6/20:3 n-6 ratio was considered as an indirect evidence of a Delta 5 desaturase activity depression. This assumption was corroborated by studying the transformation of [1-14C]eicosa-8,11,14-trienoic acid into 20:4, 22:4, 22:5, 24:4 and 24:5 n-6 fatty acids. We conclude that Sertoli cells after 7 days in culture evidenced changes in the fatty acid profile similar to those described under fat deprivation. The addition of linoleic acid reverted this pattern and indicated that the Delta 5 desaturase activity is a limiting step in the polyunsaturated fatty acid biosynthesis.