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1.
Endocrinology ; 163(3)2022 03 01.
Article in English | MEDLINE | ID: mdl-34999782

ABSTRACT

A comprehensive atlas of sex steroid distribution in multiple tissues is currently lacking, and how circulating and tissue sex steroid levels correlate remains unknown. Here, we adapted and validated a gas chromatography tandem mass spectrometry method for simultaneous measurement of testosterone (T), dihydrotestosterone (DHT), androstenedione, progesterone (Prog), estradiol, and estrone in mouse tissues. We then mapped the sex steroid pattern in 10 different endocrine, reproductive, and major body compartment tissues and serum of gonadal intact and orchiectomized (ORX) male mice. In gonadal intact males, high levels of DHT were observed in reproductive tissues, but also in white adipose tissue (WAT). A major part of the total body reservoir of androgens (T and DHT) and Prog was found in WAT. Serum levels of androgens and Prog were strongly correlated with corresponding levels in the brain while only modestly correlated with corresponding levels in WAT. After orchiectomy, the levels of the active androgens T and DHT decreased markedly while Prog levels in male reproductive tissues increased slightly. In ORX mice, Prog was by far the most abundant sex steroid, and, again, WAT constituted the major reservoir of Prog in the body. In conclusion, we present a comprehensive atlas of tissue and serum concentrations of sex hormones in male mice, revealing novel insights in sex steroid distribution. Brain sex steroid levels are well reflected by serum levels and WAT constitutes a large reservoir of sex steroids in male mice. In addition, Prog is the most abundant sex hormone in ORX mice.


Subject(s)
Gonadal Steroid Hormones/analysis , Adipose Tissue, White/chemistry , Androstenedione/analysis , Animals , Dihydrotestosterone/analysis , Estradiol/analysis , Estrone/analysis , Gas Chromatography-Mass Spectrometry/methods , Gonadal Steroid Hormones/blood , Gonadal Steroid Hormones/pharmacokinetics , Male , Mice , Mice, Inbred C57BL , Orchiectomy , Progesterone/analysis , Sensitivity and Specificity , Tandem Mass Spectrometry/methods , Testosterone/analysis , Tissue Distribution
2.
Expert Opin Drug Metab Toxicol ; 16(7): 565-582, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32479127

ABSTRACT

INTRODUCTION: Gender-affirming care may include hormonal therapy to attain desired health outcomes in transgender (trans) individuals. To provide safe, affirming medical care for trans patients, health care providers must identify and manage drug-drug interactions (DDIs) between gender affirming hormonal therapy (GAHT) and other medication therapies. AREAS COVERED: This review summarizes available data on DDIs between GAHT and antiretrovirals (ARVs) or hepatitis C direct acting antivirals (DAAs). Potential pharmacokinetic and pharmacodynamic DDIs are predicted based on GAHT, ARV, and DAA pharmacology and adverse event profiles. Clinical management strategies are discussed. EXPERT OPINION: GAHT may be involved in pharmacokinetic and/or pharmacodynamic DDIs. Certain ARV classes (non-nucleoside reverse transcriptase inhibitors, protease inhibitors) may alter GAHT disposition, whereas selected ARVs (unboosted integrase inhibitors, doravirine, or rilpivirine) may have less impact on GAHT. DAAs may interact with GAHT, but the clinical relevance is unclear. ARV- and/or DAA-associated side effects (including depression, cardiovascular disease, hyperlipidemia) are important to consider in the clinical management of trans patients. Clinicians must evaluate potential DDIs and overlapping side effects between ARVs, DAAs and GAHT when providing care for trans patients.


Subject(s)
Anti-HIV Agents/administration & dosage , Antiviral Agents/administration & dosage , Gonadal Steroid Hormones/administration & dosage , Anti-HIV Agents/pharmacokinetics , Anti-HIV Agents/pharmacology , Antiviral Agents/pharmacokinetics , Antiviral Agents/pharmacology , Drug Interactions , Female , Gonadal Steroid Hormones/pharmacokinetics , Gonadal Steroid Hormones/pharmacology , HIV Infections/drug therapy , Hepatitis C/drug therapy , Humans , Male , Transgender Persons
3.
Endocrinol. nutr. (Ed. impr.) ; 63(4): 171-180, abr. 2016. ilus
Article in English | IBECS | ID: ibc-150566

ABSTRACT

GH and sex hormones are critical regulators of body growth and composition, somatic development, intermediate metabolism, and sexual dimorphism. Deficiencies in GH- or sex hormone-dependent signaling and the influence of sex hormones on GH biology may have a dramatic impact on liver physiology during somatic development and in adulthood. Effects of sex hormones on the liver may be direct, through hepatic receptors, or indirect by modulating endocrine, metabolic, and gender-differentiated functions of GH. Sex hormones can modulate GH actions by acting centrally, regulating pituitary GH secretion, and peripherally, by modulating GH signaling pathways. The endocrine and/or metabolic consequences of long-term exposure to sex hormone-related compounds and their influence on the GH-liver axis are largely unknown. A better understanding of these interactions in physiological and pathological states will contribute to preserve health and to improve clinical management of patients with growth, developmental, and metabolic disorders (AU)


La GH y las hormonas sexuales son importantes reguladores del crecimiento y la composición corporal, el desarrollo somático, el metabolismo intermediario y el dimorfismo sexual. Deficiencias en las actividades fisiológicas de estas hormonas, así como las interacciones de las hormonas sexuales con la GH, repercuten en la fisiología hepática tanto durante el desarrollo corporal como en la edad adulta. Las hormonas sexuales pueden actuar sobre el hígado por mecanismos directos, a través de sus receptores hepáticos, o indirectos, modulando las funciones de la GH a niveles endocrino y/o metabólico. Las hormonas sexuales pueden modular las acciones de la GH a nivel central, regulando su patrón de secreción hipofisaria, y periféricamente, modulando sus mecanismos de señalización intracelular. Las consecuencias endocrinas y/o metabólicas de la exposición prolongada a compuestos relacionados con hormonas sexuales, así como su influencia sobre el eje GH-hígado son, en gran medida, desconocidas. La comprensión de estas interacciones en diferentes estados fisiológicos y patológicos contribuirá a mantener la salud y mejorar el manejo clínico de los pacientes con transtornos del crecimiento, el desarrollo y el metabolismo (AU)


Subject(s)
Humans , Gonadal Steroid Hormones/pharmacokinetics , Human Growth Hormone/pharmacokinetics , Metabolic Diseases/physiopathology , Growth Disorders/physiopathology , Sex Characteristics
4.
Endocrinol. nutr. (Ed. impr.) ; 62(5): 210-216, mayo 2015. tab
Article in English | IBECS | ID: ibc-138674

ABSTRACT

BACKGROUND AND AIMS: Since the onset of cross hormone therapy (CHT) in transsexual individuals, there has been concern about possible chronic side effects. Our objective was to assess baseline differences in lipid profile in individuals with gender identity disorder in relation to prior CHT, and changes in the lipid profile and other cardiovascular (CV) risk factors after 24 months of treatment. Methods: Retrospective longitudinal study including all individuals assisted for the first time in the Gender Identity Unit of Catalonia from 2006 to 2010. Socio-demographical, anthropometric and laboratory data were collected. Results: We evaluated 247 transsexuals, 150 male to female (MtF: 60.7%) and 97 female to male (FtM; 39.3%). At baseline, FtM transsexuals were younger and had started prior CHT less often than MtF (13.4% vs. 64.7%; p < 0.001). During follow up, in MtF weight and BMI increased significantly, as well as systolic and diastolic blood pressure, though these latter remained within normal range. No significant differences in lipid profile were observed. FtM transsexuals also presented an increase in weight and BMI, without differences in blood pressure. A general worsening in lipid profile was observed in this group, with increased total cholesterol (166.0 ± 35.1 vs. 175.6 ± 38.2 mg/dL; p = 0.001), triglycerides (70.6 ± 30.7 vs. 102.3 ± 68.5 mg/dL; p < 0.001) and LDL cholesterol (103.8 ± 28.7 vs. 112.8 ± 30.3 mg/dL; p = .013) and decreased HDL cholesterol (52.2 ± 12.2 vs. 45.4 ± 13.8 mg/dL;p = 0.001), even though final levels were all within normal range. Conclusion: There is no detectable increase in CV risk factors in MtF transsexuals who were treated with currently prescribed estrogenic compounds, while a slight worsening in lipid profile takes place in the FtM group, though within normal limits


ANTECEDENTES Y OBJETIVOS: Desde la introducción del tratamiento hormonal cruzado (CHT) en los individuos transexuales existe preocupación sobre sus posibles efectos secundarios a largo plazo. Nuestro objetivo fue evaluar las diferencias en el perfil lipídico basal de individuos transexuales en relación con haber realizado o no CHT previo, y los cambios en dicho perfil y en otros factores de riesgo cardiovascular (FRCV) tras 24 meses de tratamiento. MÉTODOS: Estudio longitudinal retrospectivo incluyendo todos los pacientes atendidos como primera visita en nuestra unidad entre 2006 y 2010. Se recogieron datos socio-demográficos, antropométricos y de laboratorio. RESULTADOS: Se evaluaron 247 transexuales, 150 de hombre a mujer (MtF: 60.7%) y 97 de mujer a hombre (FtM: 39.3%). Basalmente, los transexuales FtM eran más jóvenes y habían realizado CHT previamente con mayor frecuencia (13.4% vs. 64.7%; p < 0.001). Durante el seguimiento el peso y el IMC aumentaron en MtF de forma significativa, así como la tensión arterial sistólica y diastólica, aunque estos dos últimos se mantuvieron dentro de la normalidad. No se objetivaron diferencias significativas en el perfil lipídico. Los transexuales FtM también presentaron un incremento de peso e IMC, sin diferencias en la tensión arterial. Se observó un empeoramiento generalizado del perfil lipídico en este grupo, con aumento del colesterol total (166.0 ± 35.1 vs. 175.6 ± 38.2 mg/dL; p = 0.001), triglicéridos (70.6 ± 30.7 vs. 102.3 ± 68.5 mg/dL; p < 0.001) y colesterol LDL y empeoramiento del colesterol HDL (52.2 ± 12.2 vs. 45.4 ± 13.8 mg/dL; p = 0.001). CONCLUSIÓN: No se produce un incremento significativo en los FRCV en los transexuales MtF tratados con los compuestos estrogénicos actuales, mientras que se observa un discreto empeoramiento en el perfil lipídico en los transexuales FtM, aunque los valores se mantienen dentro de la normalidad


Subject(s)
Humans , Cardiovascular Diseases/prevention & control , Gonadal Steroid Hormones/pharmacokinetics , Risk Factors , Transsexualism/drug therapy , Retrospective Studies , Lipids/blood , Hyperlipidemias/prevention & control , Time/statistics & numerical data
5.
Nutr. hosp ; 30(4): 825-830, oct. 2014. tab
Article in English | IBECS | ID: ibc-134912

ABSTRACT

Background: The chronic use of steroid hormones can lead to alterations in the lipid profile such as an increase in LDL and decrease in HDL levels . The effect of flaxseed on lipid profiles has been widely investigated. Aim: Evaluate the lipid profile of adult male Wistar rats fed with flax based meals and submitted to androgenic hyperstimulation. Material and Methods: Forty Wistar rats were divided into 4 groups of 10 animals: the Control group (CG); Flax group (FG) fed a flaxseed flour-based meal; Induced group (IG); and the Induced group (IGF) that was fed a flaxseed flour-based meal. The induction was done by using silicone pellets filled with testosterone propionate (1mg), sealed with a surgical adhesive and substituted every 4 weeks. Results: Triglycerides (FG: 71.16 ± 21.95; IG: 99.16 ± 26.00 and IGF: 86.33 ± 27.16 mg/dL) and HDL-cholesterol (FG: 23.05 ± 1.67; IG: 29.06 ± 7.24 and IGF: 26.06 ± 3.56 mg/dL) were significantly lower in the experimental groups. The FG and IGF (41.16 ± 3.97 and 49.66 ± 11.25 mg/dL, respectively) showed significantly lower levels of cholesterol than the other groups(CG: 78,85 ± 11.58 and IG: 70,83 ± 14.85 mg/dL). Regarding LDL levels, the IG showed significantly higher concentrations (21,93 ± 8,84 mg/dL) than the others groups (CG: 7,81 ± 5,37; FG: 3,88 ± 1,32 and IGF: 6,66 ± 7,24 mg/dL). Conclusions: The flaxseed has a relevant effect on the lipid profile of animals submitted to androgenic hyperstimulation (AU)


Introducción: El uso crónico de hormonas esteroides puede causar alteraciones en el perfil lipídico como el aumento de las LDL y reducción de las HDL. Los efectos de la linaza en el perfil lipídico han sido extensivamente investigados. Objetivo: Evaluar el perfil lipídico de ratas Wistar machos adultos alimentados con piensos a base de linaza y sometidos a hiperestimulaciones androgénicas. Materiales y Métodos: Cuarenta ratas Wistar fueron divididos en 4 grupos de 10 animales: Grupo control (GC); Grupo de linaza (GL), alimentados con piensos a base de harina de linaza ; Grupo Inducido (GI); y Grupo Inducido (GIL) alimentados con piensos a base de harina de linaza. La inducción fue realizada utilizando pellets de silicona rellenados con propionato de testosterona (1 mg) cerrados con un adhesivo quirúrgico y sustituidos cada 4 semanas. Resultados: Los triglicéridos (GL: 71.16 ± 21.95; GI: 99.16 ± 26.00; GIL: 86.33 ± 27.16 mg/dL) y colesterol-HDL (GL: 23.05 ± 1.67; GI: 29.06 ± 7.24; GIL: 26.06 ± 3.56 mg/dL) estaban significativamente más bajos en los grupos experimentales. EL GL (41.16 ± 3.97 mg/dL) y GIL (49.66 ± 11.25 mg/dL) presentaron niveles menores de colesterol que los otros grupos (GC: 78,85 ± 11.58; GI: 70,83 ± 14.85 mg/dL) y el GI concentraciones significativamente mayores de LDL (21,93 ± 8,84 mg/dL) que los otros grupos (GC: 7,81 ± 5,37; GL: 3,88 ± 1,32; GIL: 6,66 ± 7,24 mg/dL). Conclusión: La linaza presenta efectos relevantes en el perfil lipídico de animales sometidos a hiperestimulaciones androgénicas (AU)


Subject(s)
Animals , Rats , Gonadal Steroid Hormones/pharmacokinetics , Flax , Seeds , Plant Extracts/pharmacokinetics , Lipid Metabolism , Cholesterol/blood , Protective Agents/pharmacokinetics , Case-Control Studies
6.
Mali Med ; 25(3): 1-9, 2010.
Article in French | MEDLINE | ID: mdl-21441085

ABSTRACT

Eight in 1,000 people in the world suffer from epilepsy, and 80 % of them are in the developing countries [1]. Sub-Saharan Africa and Latin America have higher median prevalence's 15.4 % and 12.4 %, respectively, compared to the prevalence in Europe, 5.4 %, and in North America, 5-10 % [2]. On this epidemiological inequality overlays a considerable disparity in the quality of care given to people with epilepsy, between developed and developing countries, and rural and urban areas. In this context, one of the most controversial subject regarding epilepsy is the care given to epileptic patients and their offspring. In fact, being a woman with epilepsy is not as being a man. The specific concerns about women with epilepsy are essentially sexual development, contraception, reproduction, fertility, and anatomic and cognitive teratogenicity of anti-epileptic drugs. The awareness campaign of women with epilepsy starts from puberty until menopause. About one third of epileptic women experience variations in their disease linked to menses, probably due to the neurotoxicity of oestrogens (not counterbalanced by progestatives). The problem with the teratogenicity of anti-epileptic drugs is not resolved yet despite the availability of new molecules. A close collaboration between health practitioners (obstetricians and neurologists) and an awareness of health professionals are essential for a global care of pregnant epileptic women or at age to conceive.


Subject(s)
Epilepsy/therapy , Women's Health , Abnormalities, Drug-Induced/etiology , Abnormalities, Drug-Induced/prevention & control , Age Distribution , Anticonvulsants/adverse effects , Anticonvulsants/pharmacokinetics , Anticonvulsants/therapeutic use , Contraceptives, Oral, Hormonal/pharmacokinetics , Developing Countries , Disease Management , Drug Interactions , Epilepsy/drug therapy , Epilepsy/epidemiology , Epilepsy/physiopathology , Female , Gonadal Steroid Hormones/pharmacokinetics , Gonadal Steroid Hormones/physiology , Health Services Accessibility , Humans , Infant, Newborn , Infant, Newborn, Diseases/etiology , Infant, Newborn, Diseases/prevention & control , Mali/epidemiology , Pregnancy , Pregnancy Complications/drug therapy , Prevalence , Reproductive Physiological Phenomena/drug effects , Sex Distribution
7.
Basic Clin Pharmacol Toxicol ; 103(2): 157-65, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18816299

ABSTRACT

The cytochrome P450 enzyme CYP1A2 is crucial for the metabolism of many drugs, for example, tizanidine. As the effects of several non-steroidal anti-inflammatory drugs (NSAID) and female sex steroids on CYP1A2 activity in vitro are unknown, their effects on phenacetin O-deethylation were studied and compared with the effects of model inhibitors in human liver microsomes, followed by prediction of their interaction potential with tizanidine in vivo. In vitro, fluvoxamine, tolfenamic acid, mefenamic acid and rofecoxib potently inhibited CYP1A2 [the 50% inhibitory concentration (IC(50)) < 10 microM]. Ethinyloestradiol, celecoxib, desogestrel and zolmitriptan were moderate (IC(50) 20-200 microM), and etodolac, ciprofloxacin, etoricoxib and gestodene weak inhibitors of CYP1A2 (IC(50) > 200 microM). At 100 microM, the other tested NSAIDs and steroids inhibited CYP1A2 less than 35%. Pre-incubation increased the inhibitory effects of rofecoxib, progesterone and desogestrel. Using the free portal plasma inhibitor concentration and the competitive inhibition model, the effect of fluvoxamine and the lack of effects of tolfenamic acid and celecoxib on tizanidine pharmacokinetics in human beings were well predicted. However, the effects of ciprofloxacin, rofecoxib and oral contraceptives were greatly underestimated even when the predictions were based on their total portal plasma concentration. Besides rofecoxib, and possibly mefenamic acid, other NSAIDs were predicted not to significantly inhibit CYP1A2 in human beings. The type of enzyme inhibition, particularly metabolism-dependent inhibition, free inhibitor concentration and accumulation of the inhibitor into the hepatocytes should be considered in extrapolations of in vitro results to human beings.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Contraceptive Agents, Female/pharmacology , Cytochrome P-450 CYP1A2 Inhibitors , Enzyme Inhibitors/pharmacology , Gonadal Steroid Hormones/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Area Under Curve , Contraceptive Agents, Female/pharmacokinetics , Cytochrome P-450 CYP1A2/metabolism , Drug Interactions , Enzyme Inhibitors/pharmacokinetics , Female , Gonadal Steroid Hormones/pharmacokinetics , Humans , In Vitro Techniques , Microsomes, Liver/drug effects , Microsomes, Liver/enzymology , Predictive Value of Tests
8.
Gynecol Obstet Invest ; 66(2): 111-8, 2008.
Article in English | MEDLINE | ID: mdl-18446040

ABSTRACT

BACKGROUND/AIMS: There is a lack of evidence in the literature supporting vaginal application of a combination hormone-containing cream for local and systemic symptom relief. This pilot study examined the extent of absorption of a single cream containing estriol, estradiol, progesterone, DHEA, and testosterone. METHODS: A combination cream was administered to 12 postmenopausal women in two differing doses over two independent time periods. Following 28 days (arm 1) and an additional 14 days (arm 2), measurement of hormones in saliva and blood and measurements of symptom relief, patient tolerability, and health-related quality of life (HRQoL) were obtained. RESULTS: The dosage and time of evaluation for study arm 1 was not ideal for providing documented increases in hormone levels. HRQoL measurements supported measured improvement in this arm. The second arm did document absorption of the various hormones when given vaginally. CONCLUSION: This study is the first documenting systemic absorption of multiple hormones by both saliva and blood as well as improvement of HRQoL. This therapy was generally well-tolerated with only 2 patients experiencing minor irritation, not necessitating discontinuation. Additional studies in larger numbers of patients will provide better knowledge for clinicians wanting to provide similar therapy at the lowest effective dose.


Subject(s)
Gonadal Steroid Hormones/administration & dosage , Gonadal Steroid Hormones/pharmacokinetics , Hormone Replacement Therapy/methods , Mucous Membrane/metabolism , Vagina/metabolism , Administration, Intravaginal , Adsorption , Aged , Dehydroepiandrosterone/administration & dosage , Dehydroepiandrosterone/blood , Dehydroepiandrosterone/pharmacokinetics , Emollients/administration & dosage , Emollients/pharmacokinetics , Estradiol/administration & dosage , Estradiol/blood , Estradiol/pharmacokinetics , Estriol/administration & dosage , Estriol/blood , Estriol/pharmacokinetics , Female , Gonadal Steroid Hormones/blood , Humans , Middle Aged , Pilot Projects , Quality of Life , Saliva/metabolism , Testosterone/administration & dosage , Testosterone/blood , Testosterone/pharmacokinetics
9.
Environ Res ; 104(1): 4-21, 2007 May.
Article in English | MEDLINE | ID: mdl-16616135

ABSTRACT

Differences in exposure, anatomy, physiology, biochemistry, and behavior between males and females are a dominant theme in biology, transcending the plant and animal kingdoms. Yet differences due to sex and gender have not received adequate attention in human or animal toxicology nor always in epidemiology. Generalizations are often made about species' responses to xenobiotics, without data or consideration of female/male differences. Despite the leading role that pharmacology and drug development play in elucidating toxicokinetics, gender studies are relatively recent. Phenomenologic or clinical observations of sex differences often go unexplored, but pharmaceutical companies recognize the importance of enhanced understanding of toxicokinetics and toxicodynamics and emphasize the value of translational or integrational research--bringing laboratory findings to bedside applications and bedside questions to laboratory study. However, for many years Food and Drug Administration guidelines specifically precluded participation of females in many drug studies. Many occupational epidemiology studies, on which much of our understanding of toxic effects is based, begin by excluding women and minorities. Sex differentiation begins in the embryo under genetic and hormonal control. Changes affecting exposure, susceptibility, risk, and health continue throughout life. This paper provides a framework for analyzing the level(s) at which gender differences arise. The framework addresses exposure, toxicokinetics, toxicodynamics, and modulating influences. Men and women differ in many aspects of vulnerability to xenobiotics and other stressors, beginning with their opportunities for exposure. Toxicokinetic differences mainly involve metabolism, with few differences in absorption yet demonstrated. In addition, lifestyle, psychosocial, and hormonal factors modify the kinetics and responsiveness. Some phenomena fit the Classic Sex Hormone Paradigm in which castration (with and without hormone replacement) and administration of the opposite sex hormone demonstrate the primary regulatory role of sex hormones. Many phenomena, however, differ between males and females without showing a clear-cut relationship with the sex hormones. Since every cell both has a sex chromosome (X or Y) and is exposed to hormones, elegant techniques are just beginning to tease apart genetic from hormonal influences. Wherever possible, studies should use balanced gender and gender x age designs and should analyze data by sex and interactions, rather than simply adjusting for (discarding) gender. Power should be adequate, or lack of power (if inevitable) should be clearly stated.


Subject(s)
Environmental Exposure , Environmental Pollutants/pharmacokinetics , Environmental Pollutants/toxicity , Sex Characteristics , Toxicology/methods , Animals , Female , Gonadal Steroid Hormones/pharmacokinetics , Gonadal Steroid Hormones/toxicity , Humans , Male , Risk Factors , Sex Factors , Toxicology/standards , Viscera/drug effects , Xenobiotics/pharmacokinetics , Xenobiotics/toxicity
10.
Rev. esp. enferm. metab. óseas (Ed. impr.) ; 14(1): 5-14, ene.-feb. 2005. ilus, graf
Article in Es | IBECS | ID: ibc-038677

ABSTRACT

Es conocido que los esteroides sexuales ejercen un papel regulador en el metabolismoóseo. En los últimos años se han efectuado importantes avances paraesclarecer en qué consiste y cómo se realiza esta regulación, definiendo, apartedel ya conocido mecanismo genómico a través del receptor esteroideo, una acciónautocrina y paracrina mediada por citocinas y un mecanismo no genómicoy no dependiente del sexo que abre una nueva línea de investigación con importantesimplicaciones terapéuticas.Los avances en las técnicas de laboratorio y en la investigación transgénica hanpermitido establecer la localización y función de los receptores esteroideos en losdistintos componentes del compartimento óseo, con hallazgos sumamente interesantesen el campo de los andrógenos y de su receptor.El objetivo de este artículo es revisar los datos derivados de las investigacionesin vitro e in vivo en animales y humanos sobre el mecanismo de acción de los esteroidessexuales en el hueso y su papel en la homeostasis ósea y en la protecciónfrente a la osteoporosis. Prestaremos especial atención a la importancia delsexo en la modulación de su efecto


It is known that sexual steroids have a regulating role in bone metabolism. Inrecent years, important advances have been made to clarify what this regulationconsists in and how it occurs, defining, in addition to the already knowngenomic mechanism through the steroid receptor, an autocrine and paracrineaction mediated by cytokines and a non-genomic mechanism, not gender dependent,that opens a new line of investigation with important therapeutic implications.The advances in laboratory techniques and transgenic investigation have madeit possible to establish the site and function of the steroid receptors in the differentbone compartment components, with extremely interesting findings inthe field of androgens and their receptor.This article aims to review the data derived from in vitro and in vivo researchin animals and humans on the action mechanism of sexual steroids on the boneand their role in bone homeostasis and on protection against osteoporosis. Wegive special attention to the importance of gender in the modulation of theireffect


Subject(s)
Male , Female , Humans , Gonadal Steroid Hormones/pharmacokinetics , Bone and Bones , Paracrine Communication/physiology , Autocrine Communication/physiology , Cytokines/physiology , Sex Factors
12.
Med Princ Pract ; 13(1): 2-9, 2004.
Article in English | MEDLINE | ID: mdl-14657611

ABSTRACT

Hemorrhage following accidental injuries is a common cause of death in the industrialized world. Moreover, the impact of elective surgery and solid organ transplantation sometimes results in low flow conditions similar to those seen following hemorrhagic shock. A shortage in O(2) availability, or hypoxia, leads to sequential changes in cell metabolism and morphology, including inflammatory responses and the expression of hypoxia-inducible transcription factor-1, which controls the cellular adaptation to hypoxia. These endogenous adaptive responses show that O(2) deprivation is not an unforeseen event for cells. The purpose of this review article is to discuss the pathophysiologic principles of shock and the metabolic alterations that cells undergo during low flow conditions. Moreover, the rationale for therapeutic intervention by administering ATP-MgCl(2) and sex steroids following shock and trauma will also be discussed.


Subject(s)
Adenosine Triphosphate/therapeutic use , Gonadal Steroid Hormones/therapeutic use , Shock, Hemorrhagic/drug therapy , Shock, Hemorrhagic/metabolism , Adenosine Triphosphate/pharmacokinetics , Animals , Gonadal Steroid Hormones/pharmacokinetics , Humans , Hypoxia/metabolism , Shock, Traumatic/drug therapy , Shock, Traumatic/metabolism
13.
Can J Physiol Pharmacol ; 81(4): 359-70, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12769228

ABSTRACT

This review examines possible role of progesterone receptor (PR) and androgen receptor (AR) "cross-talk" in the expression of courtship behaviour in the ring dove (Streptopelia risoria). In doves, although androgen has been mostly associated with aggressive courtship behaviour and progesterone with the initiation of incubation, progesterone administration to courting birds terminates the aggressive component of courtship whilst having no effect on nesting behaviour. Recent results in doves have identified a high density of androgen receptor and progesterone receptor immunoreactivity (AR-ir and PR-ir) in the hypothalamus of both sexes in regions known to be directly involved in courtship and incubation behaviour. Nuclear AR-ir in courting birds is widespread throughout the brain. Nuclear PR-ir is only localized in discrete regions of the preoptic hypothalamus of both sexes. In the anterior and posterior hypothalamus of courting birds an increase number of AR-ir and PR-ir neurons colocalizes (70-90%) in the nucleus preopticus anterior (POA), nucleus preopticus medialis (POM), nucleus preopticus paraventricularis magnocellularis (PPM), nucleus hypothalami lateralis posterioris (PLH), and tuberal hypothalamus (Tu). A lower percentage of colocalization is seen in birds at other stages of the breeding cycle. The high percentage of AR-ir and PR-ir colocalization in the preoptic hypothalamus of courting doves supports previous reports involving progesterone acting in these brain regions to terminate the androgen-dependent aggressive courtship behaviour in male doves. The increase in PR-ir staining intensity in AR-ir neurons in courting birds suggests that this progesterone-dependent termination of aggressive courtship display in males occurs at the receptor level and may be orchestrated by central oestrogen.


Subject(s)
Animal Communication , Brain/physiology , Courtship , Gonadal Steroid Hormones/pharmacokinetics , Receptors, Steroid/drug effects , Songbirds/physiology , Animals , Brain/drug effects , Female , Fluorescence , Hypothalamus , Male , Receptors, Steroid/immunology
14.
Endocr Res ; 29(1): 43-51, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12665317

ABSTRACT

Both experimental and clinical research support the conclusion that thyroid tumors are sex dependent. Also, several studies have pointed out that the use of oral contraceptives is associated with a higher risk of thyroid tumor. Most of the existing reports suggest indirect effects of sex steroids on thyroid tumor growth in women. In this work, we present data to support the direct promoting effect of estradiol and testosterone on carcinogen-induced thyroid tumorigenesis. Thyroid tumors were induced in rats by a combination of N-nitrosodiisopropanolamine (DHPN) and phenobarbital (PB) treatment. Serum thyroid hormones, thyroid stimulating hormone (TSH), steroid hormones, thyroidal steroid concentration, androgen and estrogen receptors were quantified. Serum thyroid hormones and TSH suggested euthyroid status of the all experimental animals. Ovariectomy decreased the incidence of DHPN + PB induced thyroid tumor when compared with ovary intact rats and estradiol/testosterone supplementation increased the same. Thyroidal estradiol level and its nuclear receptors increased in the tumor tissue specifically. Testosterone supplementation to DHPN-treated ovariectomized rats specifically induced the development of malignant thyroid tumors. Addition of estradiol in vitro to thyrocytes induced a higher proliferation rate. Our data proves a direct promoting role of estrogen on carcinogen-induced thyroid tumor development.


Subject(s)
Carcinogens , Estradiol/pharmacology , Gonadal Steroid Hormones/pharmacology , Nitrosamines , Testosterone/pharmacology , Thyroid Neoplasms/chemically induced , Animals , Estradiol/pharmacokinetics , Female , Gonadal Steroid Hormones/pharmacokinetics , Hormones/blood , Incidence , Rats , Rats, Wistar , Receptors, Androgen/metabolism , Receptors, Estrogen/metabolism , Testosterone/pharmacokinetics , Thyroid Gland/metabolism , Thyroid Neoplasms/epidemiology
15.
Psiquis (Madr.) ; 24(3): 115-118, 2003.
Article in Es | IBECS | ID: ibc-24798

ABSTRACT

La bulimia nerviosa se caracteriza por la presencia de atracones recurrentes y conductas purgativas conpensatorias o ayuno prolongado. Afecta generalmente a mujeres jóvenes y es raro su inicio en edades avanzadas. Se expone el caso de una mujer de 50 años que comienza con un cuadro de bulimia nerviosa dos años antes, coincidiendo con la menopausia. La bulimia tiene relación con la sintomatología afectiva y la menopausia se asocia con más frecuencia de síntomas depresivos lo que se atribuye a los cambios en los niveles de estrógenos a nivel cerebral. Se analiza el posible efecto antidepresivo de los estrógenos y la relación entre factores hormonales y los trastornos afectivos (AU)


Subject(s)
Female , Middle Aged , Humans , Bulimia/etiology , Menopause/psychology , Estrogen Replacement Therapy , Depression/complications , Gonadal Steroid Hormones/pharmacokinetics
16.
J Control Release ; 79(1-3): 173-82, 2002 Feb 19.
Article in English | MEDLINE | ID: mdl-11853929

ABSTRACT

Starch-g-poly(acrylic acid) copolymers or grafted starches synthesized by 60Co irradiation or chemical modification and co-freeze-dried starch/poly(acrylic acid) mixtures were evaluated on their ex vivo bioadhesion capacity. The buccal absorption of testosterone from a bioadhesive tablet formulated with the grafted starches or starch/poly(acrylic acid) mixtures was investigated. The results were compared to a reference formulation (physical mixture of 5% Carbopol 974P and 95% Drum Dried Waxy Maize). Rice starch-based irradiated grafted starches showed the best bioadhesion results. Partial neutralization of the acrylic acid with Ca(2+) ions resulted in significantly higher bioadhesion values compared to the reference. Ca(2+) and Mg(2+) partially neutralized maltodextrin-based irradiated grafted starches showed significantly higher bioadhesion values compared to the reference formulation. The chemically modified grafted starches showed significantly higher adhesion force values than for the reference tablet. None of the co-freeze-dried starch/poly(acrylic acid) mixtures showed significantly higher bioadhesion results than the reference (Bonferroni test, P<0.05). A chemically modified grafted starch could sustain the 3 ng/ml plasma testosterone target concentration during +/- 8 h (T(>3 ng/ml)). By lyophilization of a partially neutralized irradiated grafted starch, the in vivo adhesion time (22.0 +/- 7.2 h) and the T(>3 ng/ml) (13.5 +/- 1.3 h) could be increased. The absolute bioavailability of the lyophilized formulation approached the reference formulation. Some of the grafted starches showed to be promising buccal bioadhesive drug carriers for systemic delivery.


Subject(s)
Adhesives/chemistry , Starch/analogs & derivatives , Starch/chemistry , Testosterone/pharmacokinetics , Adhesives/pharmacokinetics , Animals , Biological Availability , Chemistry, Pharmaceutical , Dogs , Drug Carriers/chemistry , Drug Carriers/pharmacokinetics , Drug Evaluation, Preclinical , Gonadal Steroid Hormones/chemistry , Gonadal Steroid Hormones/pharmacokinetics , Male , Starch/pharmacokinetics , Testosterone/chemistry
17.
J Androl ; 23(1): 84-91, 2002.
Article in English | MEDLINE | ID: mdl-11780927

ABSTRACT

Men with hypogonadism require testosterone replacement for optimal health. In the United States, testosterone is currently administered by daily transdermal patches, topical gels or intramuscular injections every 1-3 weeks. Biodegradable polylactide-co-glycolide microcapsules are currently used for long-term drug delivery in humans. Such microcapsules that contain testosterone could provide a better means of long-term testosterone therapy. We therefore studied the pharmacokinetics and pharmacodynamics of testosterone release from testosterone microcapsules in men with hypogonadism. Fourteen men who had been treated previously with testosterone were enrolled in an open-label, prospective study of testosterone microcapsule administration. Subjects were enrolled if 2 consecutive serum total testosterone levels were lower than 8.7 nmol/L after a 4-week washout from testosterone therapy. Subjects were injected with a single dose of either 267 mg (n = 7) or 534 mg (n = 7) of (Viatrel) testosterone microcapsule, and serum total testosterone, dihydrotestosterone, estradiol, sex-hormone binding globulin, luteinizing hormone, and follicle-stimulating hormone levels were determined at days -14, -7, and 0 before the injection; at days 1, 2, and 7 after the injection; and then weekly thereafter for 8-12 weeks. Mean serum total testosterone levels peaked immediately following injection on day 1 at 25.2 +/- 2.6 nmol/L in the 267 mg group and 34.7 +/- 2.4 nmol/L in the 534 mg group. Total serum testosterone levels declined gradually and fell below 8.7 nmol/L at 42 days after injection in the 267 mg group, and 70 days after injection in the 534 mg group. Estradiol and dihydrotestosterone levels followed a similar pattern. Mean serum free testosterone also peaked immediately following injection on day 1 at 0.51 +/- 0.05 nmol/L in the 267 mg group and 0.97 +/- 0.08 nmol/L in the 534 mg group. No significant adverse reactions were seen, although 2 subjects complained of transient tenderness and fullness at their injection sites. We conclude that a single injection of 534 mg of testosterone microcapsules to men with hypogonadism normalizes serum hormone levels for up to 10-11 weeks, albeit with a pronounced early peak and a relatively long period of low-normal serum total testosterone. Subcutaneously administered testosterone microcapsules may provide a safe and convenient method for the long-term treatment of male hypogonadism or testosterone replacement in male contraceptive regimens.


Subject(s)
Gonadal Steroid Hormones/pharmacokinetics , Hypogonadism/drug therapy , Testosterone/pharmacokinetics , Affect/drug effects , Capsules , Contraceptive Agents , Dihydrotestosterone/blood , Ejaculation/drug effects , Estradiol/blood , Gonadal Steroid Hormones/administration & dosage , Gonadal Steroid Hormones/adverse effects , Gonadal Steroid Hormones/blood , Humans , Injections, Subcutaneous , Male , Polyesters , Sex Hormone-Binding Globulin/metabolism , Testosterone/administration & dosage , Testosterone/adverse effects , Testosterone/blood
18.
J Clin Endocrinol Metab ; 86(4): 1814-22, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11297623

ABSTRACT

Human male hormonal contraceptive regimens do not consistently induce azoospermia, and the basis of this variable response is unclear. This study used nine adult macaque monkeys (Macaca fascicularis) given testosterone (T) implants for 20 weeks to study changes in germ cell populations in relation to sperm output. Germ cell numbers were determined using the optical disector stereological method. Four animals achieved consistent azoospermia (azoo group), whereas five animals did not (nonazoo group). T-induced gonadotropin suppression in all animals decreased A pale (Ap) spermatogonia to 45% of baseline within 2 weeks, leading to decreased B spermatogonia (32--38%) and later germ cells (20--30%) after 14 and 20 weeks. Though the reduction in later germ cell types could be primarily attributed to the loss of spermatogonia, the data suggested that some cells were lost during the spermatocyte and spermatid phase of development. B spermatogonial number was more markedly suppressed in azoospermic animals, compared with the nonazoo group, as was the conversion ratio between Ap and B spermatogonia. Abnormal retention of elongated spermatids (failed spermiation) was also prominent in some animals after long-term T administration. We conclude that: 1) the variable suppression of sperm output is attributed to the degree of inhibition of germ cell development from type B spermatogonia onwards, and this is related to the degree of FSH suppression; and 2) inhibition of Ap and B spermatogonial development and of spermiation are the major defects caused by long-term T administration to monkeys.


Subject(s)
Gonadal Steroid Hormones/pharmacology , Gonadotropins/antagonists & inhibitors , Sertoli Cells/physiology , Spermatogonia/drug effects , Spermatogonia/physiology , Spermatozoa/drug effects , Spermatozoa/physiology , Testosterone/pharmacology , Animals , Follicle Stimulating Hormone/blood , Gonadal Steroid Hormones/pharmacokinetics , Luteinizing Hormone/blood , Macaca fascicularis , Male , Sperm Count , Spermatogonia/classification , Spermatozoa/cytology , Testosterone/pharmacokinetics
19.
J Vet Pharmacol Ther ; 23(3): 121-9, 2000 Jun.
Article in English | MEDLINE | ID: mdl-11110098

ABSTRACT

Androgenic steroids are used in female greyhound dogs to prevent the onset of estrus; moreover, these steroids also have potent anabolic activity. As anabolic steroids increase muscle mass and aggression in animals, the excessive use of these agents in racing greyhounds gives an unfair performance advantage to treated dogs. The biotransformation of most anabolic steroids has not been determined in greyhound dogs. The objective of the present study was to identify the urinary metabolites of testosterone, methyltestosterone, mibolerone, and boldenone in greyhound dogs. These steroids were administered orally (1 mg/kg) to either male or female greyhound dogs and urine samples were collected pre-administration and at 2, 4, 8, 12, 24, 72, and 96 h post-administration. Urine extracts were analyzed by high-performance liquid chromatography/mass spectrometry (HPLC/MS) to identify major metabolites and to determine their urinary excretion profiles. Major urinary metabolites, primarily glucuronide, conjugated and free, were detected for the selected steroids. Sulfate conjugation did not appear to be a major pathway for steroid metabolism and excretion in the greyhound dog. Phase I biotransformation was also evaluated using greyhound dog liver microsomes from untreated dogs. The identification of several in vivo steroid metabolites generated in this study will be useful in detecting these steroids in urine samples submitted for drug screening.


Subject(s)
Anabolic Agents/metabolism , Gonadal Steroid Hormones/metabolism , Methyltestosterone/metabolism , Microsomes, Liver/metabolism , Nandrolone/analogs & derivatives , Testosterone/analogs & derivatives , Testosterone/metabolism , Administration, Oral , Anabolic Agents/pharmacokinetics , Anabolic Agents/urine , Animals , Biotransformation , Chromatography, High Pressure Liquid , Dogs , Female , Gonadal Steroid Hormones/pharmacokinetics , Gonadal Steroid Hormones/urine , Male , Methyltestosterone/urine , Nandrolone/metabolism , Nandrolone/urine , Testosterone/pharmacokinetics , Testosterone/urine
20.
Eur J Pharm Sci ; 11(1): 59-68, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10913754

ABSTRACT

The optimal skin type for in vitro permeability studies depends on the purpose of the specific transdermal study. In a number of cases, it may be advantageous to use animal skin as an alternative to human skin although they have different characteristics. Recently, Göttingen minipigs have been reported as good models in toxicological and pharmacokinetic studies of drug substances. In this paper, the potential use of skin from the Göttingen minipig is evaluated by studying three model drug substances (nicotine, salicylic acid and testosterone) through skin from humans, domestic pigs and three ages of the Göttingen minipig. An analysis of variance and a Student's t-test showed that both the skin from the Göttingen minipig and the domestic pig possessed transdermal permeabilities, which correlated with human skin and exhibited a lower intra- and intervariation. Furthermore, it was shown that permeability and variation of fluxes through skin from Göttingen minipigs were dependent on the age of the minipig and of the drug substance. It is concluded that the Göttingen minipig, like the domestic pig, is a good skin model for in vitro permeation through human skin.


Subject(s)
Skin Absorption/physiology , Skin/metabolism , Swine, Miniature/metabolism , Administration, Cutaneous , Age Factors , Animals , Anti-Infective Agents/pharmacokinetics , Gonadal Steroid Hormones/pharmacokinetics , Humans , Nicotine/pharmacokinetics , Nicotinic Agonists/pharmacokinetics , Salicylic Acid/pharmacokinetics , Swine , Testosterone/pharmacokinetics
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