641 research outputs found
Tissue steroid levels in response to reduced testicular estrogen synthesis in the male pig, Sus scrofa.
Production of steroid hormones is complex and dependent upon steroidogenic enzymes, cofactors, receptors, and transporters expressed within a tissue. Collectively, these factors create an environment for tissue-specific steroid hormone profiles and potentially tissue-specific responses to drug administration. Our objective was to assess steroid production, including sulfated steroid metabolites in the boar testis, prostate, and liver following inhibition of aromatase, the enzyme that converts androgen precursors to estrogens. Boars were treated with the aromatase inhibitor, letrozole from 11 to 16 weeks of age and littermate boars received the canola oil vehicle. Steroid profiles were evaluated in testes, prostate, and livers of 16, 20, and 40 week old boars using liquid chromatography/mass spectrometry. Testis, prostate, and liver had unique steroid profiles in vehicle-treated animals. Only C18 steroid hormones were altered by treatment with the aromatase inhibitor, letrozole; no significant differences were detected in any of the C19 or C21 steroids evaluated. Testis was the only tissue with significantly decreased free estrogens following treatment with the aromatase inhibitor; estrone and estradiol concentrations were lower (p < 0.05) in testes from 16, 20, and 40 week letrozole-treated boars. However, concentrations of the sulfated conjugates, estrone-sulfate and estradiol-sulfate, were significantly decreased (p<0.05) in 16 and 20 week boar testes, prostates, and livers from letrozole-treated boars. Hence, the distribution of estrogens between the free and conjugated forms was altered in a tissue-specific manner following inhibition of aromatase. The results suggest sulfated testicular estrogens are important estrogen precursors for the prostate, potentially enabling peripheral target tissues to synthesize free estrogens in the male pig
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Tissue steroid levels in response to reduced testicular estrogen synthesis in the male pig, Sus scrofa.
Production of steroid hormones is complex and dependent upon steroidogenic enzymes, cofactors, receptors, and transporters expressed within a tissue. Collectively, these factors create an environment for tissue-specific steroid hormone profiles and potentially tissue-specific responses to drug administration. Our objective was to assess steroid production, including sulfated steroid metabolites in the boar testis, prostate, and liver following inhibition of aromatase, the enzyme that converts androgen precursors to estrogens. Boars were treated with the aromatase inhibitor, letrozole from 11 to 16 weeks of age and littermate boars received the canola oil vehicle. Steroid profiles were evaluated in testes, prostate, and livers of 16, 20, and 40 week old boars using liquid chromatography/mass spectrometry. Testis, prostate, and liver had unique steroid profiles in vehicle-treated animals. Only C18 steroid hormones were altered by treatment with the aromatase inhibitor, letrozole; no significant differences were detected in any of the C19 or C21 steroids evaluated. Testis was the only tissue with significantly decreased free estrogens following treatment with the aromatase inhibitor; estrone and estradiol concentrations were lower (p < 0.05) in testes from 16, 20, and 40 week letrozole-treated boars. However, concentrations of the sulfated conjugates, estrone-sulfate and estradiol-sulfate, were significantly decreased (p<0.05) in 16 and 20 week boar testes, prostates, and livers from letrozole-treated boars. Hence, the distribution of estrogens between the free and conjugated forms was altered in a tissue-specific manner following inhibition of aromatase. The results suggest sulfated testicular estrogens are important estrogen precursors for the prostate, potentially enabling peripheral target tissues to synthesize free estrogens in the male pig
Tissue steroid levels in response to reduced testicular estrogen synthesis in the male pig, Sus scrofa.
Production of steroid hormones is complex and dependent upon steroidogenic enzymes, cofactors, receptors, and transporters expressed within a tissue. Collectively, these factors create an environment for tissue-specific steroid hormone profiles and potentially tissue-specific responses to drug administration. Our objective was to assess steroid production, including sulfated steroid metabolites in the boar testis, prostate, and liver following inhibition of aromatase, the enzyme that converts androgen precursors to estrogens. Boars were treated with the aromatase inhibitor, letrozole from 11 to 16 weeks of age and littermate boars received the canola oil vehicle. Steroid profiles were evaluated in testes, prostate, and livers of 16, 20, and 40 week old boars using liquid chromatography/mass spectrometry. Testis, prostate, and liver had unique steroid profiles in vehicle-treated animals. Only C18 steroid hormones were altered by treatment with the aromatase inhibitor, letrozole; no significant differences were detected in any of the C19 or C21 steroids evaluated. Testis was the only tissue with significantly decreased free estrogens following treatment with the aromatase inhibitor; estrone and estradiol concentrations were lower (p < 0.05) in testes from 16, 20, and 40 week letrozole-treated boars. However, concentrations of the sulfated conjugates, estrone-sulfate and estradiol-sulfate, were significantly decreased (p<0.05) in 16 and 20 week boar testes, prostates, and livers from letrozole-treated boars. Hence, the distribution of estrogens between the free and conjugated forms was altered in a tissue-specific manner following inhibition of aromatase. The results suggest sulfated testicular estrogens are important estrogen precursors for the prostate, potentially enabling peripheral target tissues to synthesize free estrogens in the male pig
Combined Effects of Gestational Phthalate Exposure and Zinc Deficiency on Steroid Metabolism and Growth
Disruption of steroid hormone signaling has been implicated independently in the developmental abnormalities resulting from maternal phthalate plasticizer exposure and developmental zinc deficiency. This study investigated if secondary zinc deficiency may result from dietary exposure to a low level of di-2-ethylhexyl phthalate (DEHP) through gestation and if this could be associated with altered steroid metabolism. The interaction between marginal zinc nutrition and DEHP exposure to affect pregnancy outcome, zinc status, and steroid metabolism was also assessed. For this purpose, rats were fed a diet containing an adequate (25 mg/kg) or marginal (10 mg/kg) level of zinc without or with DEHP (300 mg/kg) from gestation day (GD) 0 until GD 19. Steroid profiles were measured in dam liver, plasma, adrenal glands, and in fetal liver by UPLC/MS-MS. In dams fed the adequate zinc diet, DEHP exposure decreased maternal weight gain and led to hepatic acute-phase response and zinc accumulation. The latter could compromise zinc availability to the fetus. DEHP and marginal zinc deficiency caused several adverse effects on the maternal and fetal steroid profiles. Interactions between DEHP exposure and marginal zinc deficient nutrition affected 17OH pregnenolone and corticosterone, while pregnenolone levels were specifically affected by DEHP exposure. Maternal marginal zinc deficiency specifically affected maternal progesterone and aldosterone, and presented evidence of increased androgen aromatization activity in maternal and fetal tissues. Results stress the potential major impact of mild DEHP exposure on maternal/fetal steroid metabolism that can be potentiated by nutritional and chronic disease states leading to zinc deficiency
Decreased adiposity and enhanced glucose tolerance in shikonin treated mice
ObjectiveObesity represents a major public health problem, and identifying natural compounds that modulate energy balance and glucose homeostasis is of interest for combating obesity and its associated disorders. The naphthoquinone shikonin has diverse beneficial properties including anti-inflammatory, anti-oxidant, and anti-microbial effects. The objective of this study is to investigate the effects of shikonin on adiposity and glucose homeostasis.MethodsThe metabolic effects of shikonin treatment on mice fed regular chow or challenged with a high-fat diet (HFD) were determined.ResultsShikonin treated mice fed regular chow exhibited improved glucose tolerance compared with controls. In addition, shikonin treated mice fed HFD displayed decreased weight gain and resistance to HFD-induced glucose intolerance. Further, shikonin treatment decreased HFD-induced hepatic dyslipidemia. These findings correlated with enhanced hepatic insulin signaling in shikonin treated mice as evidenced by increased tyrosyl phosphorylation of the insulin receptor and enhanced downstream signaling.ConclusionsThese studies identify shikonin as a potential regulator of systemic glucose tolerance, energy balance, and adiposity in vivo
Prehispanic use of chili peppers in Chiapas, Mexico.
The genus Capsicum is New World in origin and represents a complex of a wide variety of both wild and domesticated taxa. Peppers or fruits of Capsicum species rarely have been identified in the paleoethnobotanical record in either Meso- or South America. We report here confirmation of Capsicum sp. residues from pottery samples excavated at Chiapa de Corzo in southern Mexico dated from Middle to Late Preclassic periods (400 BCE to 300 CE). Residues from 13 different pottery types were collected and extracted using standard techniques. Presence of Capsicum was confirmed by ultra-performance liquid chromatography (UPLC)/MS-MS Analysis. Five pottery types exhibited chemical peaks for Capsicum when compared to the standard (dihydrocapsaicin). No peaks were observed in the remaining eight samples. Results of the chemical extractions provide conclusive evidence for Capsicum use at Chiapas de Corzo during a 700 year period (400 BCE-300 CE). Presence of Capsicum in different types of culinary-associated pottery raises questions how chili pepper could have been used during this early time period. As Pre-Columbian cacao products sometimes were flavored using Capsicum, the same pottery sample set was tested for evidence of cacao using a theobromine marker: these results were negative. As each vessel that tested positive for Capsicum had a culinary use we suggest here the possibility that chili residues from the Chiapas de Corzo pottery samples reflect either paste or beverage preparations for religious, festival, or every day culinary use. Alternatively, some vessels that tested positive merely could have been used to store peppers. Most interesting from an archaeological context was the presence of Capsicum residue obtained from a spouted jar, a pottery type previously thought only to be used for pouring liquids
Hepatic overexpression of steroid sulfatase ameliorates mouse models of obesity and type 2 diabetes through sex-specific mechanisms
The steroid sulfatase (STS)-mediated desulfation is a critical metabolic mechanism that regulates the chemical and functional homeostasis of endogenous and exogenous molecules. In this report, we first showed that the liver expression of Sts was induced in both the high fat diet (HFD) and ob/ob models of obesity and type 2 diabetes and during the fed to fasting transition. In defining the functional relevance of STS induction in metabolic disease, we showed that overexpression of STS in the liver of transgenic mice alleviated HFD and ob/ob models of obesity and type 2 diabetes, including reduced body weight, improved insulin sensitivity, and decreased hepatic steatosis and inflammation. Interestingly, STS exerted its metabolic benefit through sex-specific mechanisms. In female mice, STS may have increased hepatic estrogen activity by converting biologically inactive estrogen sulfates to active estrogens and consequently improved the metabolic functions, whereas ovariectomy abolished this protective effect. In contrast, the metabolic benefit of STS in males may have been accounted for by the male-specific decrease of inflammation in white adipose tissue and skeletal muscle as well as a pattern of skeletal muscle gene expression that favors energy expenditure. The metabolic benefit in male STS transgenic mice was retained after castration. Treatment with the STS substrate estrone sulfate also improved metabolic functions in both the HFD and ob/ob models. Our results have uncovered a novel function of STS in energy metabolism and type 2 diabetes. Liver-specific STS induction or estrogen/estrogen sulfate delivery may represent a novel approach to manage metabolic syndrome. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc
Site map of Chiapa de Corzo by CE 500 showing principle structures mentioned in text (Drawing by Ayax Moreno based on original map by Gareth W. Lowe).
<p>Site map of Chiapa de Corzo by CE 500 showing principle structures mentioned in text (Drawing by Ayax Moreno based on original map by Gareth W. Lowe).</p
MRM method parameters used in chilli analysis.
<p>MRM method parameters used in chilli analysis.</p
UPLC/MS-MS chromatograms illustrating (a) Standard dihydrocapsaicin (b) Blank (c) Representative Corza sample confirming the presence of dihydrocapsaicin.
<p>Insets: MS/MS spectra of standard dihydrocapsaicin (A) and from sample extract (B). Samples were extracted and analyzed as described in methods.</p
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