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Plasma Testosterone (plasma + testosterone)
Terms modified by Plasma Testosterone Selected AbstractsLong-term outcome of antiandrogen monotherapy in advanced prostate carcinoma: 12-year results of a phase II studyBJU INTERNATIONAL, Issue 6 2003V. Serretta OBJECTIVE To present the long-term outcome of patients with locally advanced or metastatic prostate carcinoma treated by first-line antiandrogen monotherapy. PATIENTS AND METHODS From 1983 to 1990, 41 patients with advanced prostate carcinoma were treated with flutamide monotherapy until progression or the appearance of toxicity. Twenty-five patients (61%) had T3-T4N0M0 and 16 (39%) T2,4N0,3M1 prostate carcinoma. Consensus criteria were adopted to evaluate the response. Plasma testosterone and sexual function were recorded for the first 3 years. RESULTS Flutamide was administered for up to 147 months; seven patients (17%) interrupted the treatment because of toxicity. There was an objective response in 17 (41%) patients; 20 (49%) had stable disease while four (10%) progressed. There were objective responses, lasting up to 150 months, in 82% of those with M0 and in 18% with M1 disease (P = 0.05). The median time to progression in patients with an objective response and stable disease was 45 and 16 months, respectively (P < 0.001). Thirty-one patients (76%) died from prostate cancer and 10 (24%) from unrelated diseases. The median survival was 67 and 36 months in patients with an objective response and stable disease, respectively (P < 0.001). There was an improvement in performance status in 85% and reduction in bone pain in 83% of the patients; sexual activity was maintained in 63%. CONCLUSION Monotherapy with flutamide is well tolerated. Objective responses are more frequent in patients with locally advanced disease. Patients with an objective response within 6 months have a prolonged progression-free and overall survival. [source] Brain aromatase, 5,-reductase, and 5,-reductase change seasonally in wild male song sparrows: Relationship to aggressive and sexual behaviorDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2003Kiran K. Soma Abstract In many species, territoriality is expressed only during the breeding season, when plasma testosterone (T) is elevated. In contrast, in song sparrows (Melospiza melodia morphna), males are highly territorial during the breeding (spring) and nonbreeding (autumn) seasons, but not during molt (late summer). In autumn, plasma sex steroids are basal, and castration has no effect on aggression. However, inhibition of aromatase reduces nonbreeding aggression, suggesting that neural steroid metabolism may regulate aggressive behavior. In wild male song sparrows, we examined the neural distribution of aromatase mRNA and seasonal changes in the activities of aromatase, 5,-, and 5,-reductase, enzymes that convert T to 17,-estradiol, 5,-dihydrotestosterone (5,-DHT, a potent androgen), or 5,-DHT (an inactive metabolite), respectively. Enzyme activities were measured in the diencephalon, ventromedial telencephalon (vmTEL, which includes avian amygdala), caudomedial neostriatum (NCM), and the hippocampus of birds captured during spring, molt, or autumn. Aromatase and 5,-reductase changed seasonally in a region-specific manner. Aromatase in the diencephalon was higher in spring than in molt and autumn, similar to seasonal changes in male sexual behavior. Aromatase activity in the vmTEL was high in both spring and autumn but significantly reduced at molt, similar to seasonal changes in aggression. 5,-Reductase was not elevated during molt, suggesting that low aggression during molt is not a result of increased inactivation of androgens. These data highlight the relevance of neural steroid metabolism to the expression of natural behaviors by free-living animals. © 2003 Wiley Periodicals, Inc. J Neurobiol 56: 209,221, 2003 [source] Stimulation of reproductive growth in rainbow trout (Oncorhynchus mykiss) following exposure to treated sewage effluentENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2006Birgit Hoger Abstract Rainbow trout (Oncorhynchus mykiss) were exposed to 1.5 and 15% v/v secondary treated sewage effluent for 32 weeks in flow-through mesocosms. The exposure encompassed the full period of reproductive development for rainbow trout. Trout did not show any evidence of a dose-dependent change in growth. Fish exposed to 15% effluent were the only group to show mortality (5%) over the duration of the experiment. Trout at the highest effluent concentration had significantly higher liver size than reference water fish. Both male and female trout in the 15% exposure group also exhibited significantly higher gonad weight than the reference group. In female trout, this gonad size increase could be explained by higher egg numbers. Female and male trout both displayed a significant increase in plasma 17,-estradiol levels after exposure to 15% effluent, while neither sex had dose-dependent differences in plasma testosterone. Male trout displayed elevated vitellogenin levels and reduced plasma 11-ketotestosterone concentration after exposure to 15% effluent. Chemical examination of steroidal compounds, including both estrogens and androgens, in the wastewater revealed that only estrone was detectable at a mean concentration of 4.5 ng/L. It is assumed that the effects observed in trout exposed to 15% effluent were consistent with stimulation of reproductive development due to very low levels of estrogens. Overall, long-term exposure to treated sewage effluent containing low levels of estrogen did not have significant negative implications for reproductive development in rainbow trout. [source] Plasma sex steroid concentrations and gonadal aromatase activities in African clawed frogs (Xenopus laevis) from South AfricaENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2004Markus Hecker Abstract Adult African clawed frogs (Xenopus laevis) were collected from a corn-growing region (CGR) and a non-corn-growing region (NCGR) with different exposure profiles for atrazine and related triazines. Physical, chemical, and biological parameters from the catchment areas were also measured. Frogs were surveyed for possible effects of exposure to triazine herbicides on plasma testosterone (T) and estradiol (E2) titers, gonadal aromatase activity, and gonad growth (GSI). Concentrations of both T and E2 varied among locations and were correlated to some accessory factors, such as pH, several ions, and metals. Greatest median plasma T concentrations (males: 19 ng/ml; females: 16 ng/ml) occurred in frogs inhabiting NCGR as compared to those from the CGR (males: 4 ng/ml; females: 1 ng/ml). Median E2 concentrations were also greater in frogs collected from the NCGR (males: 3 ng/ml; females: 28 ng/ml) than those in frogs from the CGR (males: 2 ng/ml; females: 5 ng/ml). Because some exposure to agricultural chemicals at both regions occurred, as did simultaneous exposures to multiple chemicals, a regression analysis was employed. Negative correlations were observed between plasma T concentrations and concentrations of atrazine, deisopropylatrazine, deethylatrazine, and tertbuthylazine in females and between T and diaminochlorotriazine in males. Estradiol in females exhibited a significant negative correlation with atrazine and deethylatrazine. No correlations were observed between gonadal aromatase activity or GSI and any of the agricultural chemicals measured. Median aromatase activities in ovaries varied among sampling sites ranging from 7 to >3,000 times greater than those in males when measurable. Testicular aromatase activity was below the detection limit of the assay in male frogs at most of the sites. Although exposure to agricultural inputs did not affect aromatase activities, effects of atrazine or coapplied pesticides on sex steroid homeostasis cannot be excluded at this point. [source] Cloning of FSH-,, LH-, and glycoprotein hormone , subunits in pejerrey Odontesthes bonariensis (Valenciennes): expression profile and relationship with GnRH expression and plasma sex steroid levels in male fishJOURNAL OF FISH BIOLOGY, Issue 6 2007L. A. Miranda Three cDNAs encoding pejerrey Odontesthes bonariensis follicle stimulating hormone-, (FSH-,), luteinizing hormone-, (LH-,) and glycoprotein-, (GPH-,) subunits were cloned and characterized. Gene expression of these subunits was analysed by real-time polymerase chain reaction (PCR) and compared with the brain gene expression of endogenous gonadotropin-releasing hormones (GnRHs): Pacific salmon GnRH (GnRH-III), pejerrey GnRH (GnRH-I) and chicken GnRH-II (GnRH-II) and plasma sex steroid levels in adult males. The nucleotide sequences of the FSH-,, LH-, and GPH-, subunits are 466, 558 and 677 base pairs long, encoding for mature peptides of 102, 118 and 98 amino acids respectively. Maturing males had high expression of FSH-, and GPH-, subunits, and intermediate levels of LH-, when compared with running ripe and spent stages. These animals had the lowest plasma testosterone (T) and 11-ketosterone (11-KT) values as well as low expression of sGnRH, cGnRH-II and pjGnRH. Running ripe males had the lowest expression of FSH-, and the highest expression of LH-, and GPH-, subunits, and of the three GnRH genes. At this stage, the highest values of T and 11-KT were observed. Spent males showed low expression of the three gonadotropin (GtH) subunits, sGnRH, pjGnRH and low levels of T. At this stage, 11-KT levels and cGnRH-II expression showed a tendency to decrease but the values were not statistically significant (P < 0·05) to running ripe stage. The present results would suggest that T and 11-KT modulate the expression of the FSH subunits. The expression of the anterior brain GnRH variants, sGnRH and pjGnRH is correlated with LH-, expression and reinforce the importance of the forebrain GnRH variants on the regulation of pituitary function. [source] Effects of Phase-Shifted Photoperiod Regimes on Oocyte Growth and Hormonal Profiles in Female Striped Bass Morone saxatilisJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2002Verapong Vuthiphandchai Phase-shifted photoperiod cycles did not induce a full shift in oogenesis during the first year cycles, but did in the following years. Spawning time, indicated by maximum oocyte diameters, was advanced up to 4 mo in females maintained under the phase-shifted advanced photoperiod, and delayed up to 4 mo when they exposed to the phase-shifted delayed photoperiod, compared to the natural spawning time in Spring (March-May). Phase-shifted photoperiod regimes shifted the profiles of plasma testosterone (T) and estradiol (E2), corresponding to the shift of oogenesis in the respective groups. Significant increases in T and E2 levels occurred during the vitellogenic phase, and these levels peaked before the occurrence of maximum oocyte diameters. The studies demonstrate that phase-shifted photoperiod regimes can be used to control oogenesis, and have implications for ensuring the year-round supply of mature female striped bass, particularly in domesticated striped bass. [source] ORIGINAL RESEARCH,ENDOCRINOLOGY: Transdermal Testosterone Gel prn Application for Hypoactive Sexual Desire Disorder in Premenopausal Women: A Controlled Pilot Study of the Effects on the Arizona Sexual Experiences Scale for Females and Sexual Function QuestionnaireTHE JOURNAL OF SEXUAL MEDICINE, Issue 1 2007Bella Chudakov MD ABSTRACT Introduction., Several studies suggest that increased plasma testosterone can improve sexual function and desire in post-oophorectomy or postmenopausal women. However, side effects of chronic daily testosterone raise questions about the generalizability of this treatment approach. Sublingual testosterone was reported to cause testosterone levels to peak after 15 minutes and then decline to baseline levels within 90 minutes. Three to 4 hours after reaching testosterone peak, increased genital sensations and sexual lust were reported. Aim., We hypothesized that a singe dose of testosterone given 4,8 hours prior to planned intercourse in women with hypoactive sexual desire disorder (HSDD) might increase desire without side effects associated with chronic use. Methods., The design was randomized double-blind crossover. Premenstrual women with HSDD received eight packets of gel or identical placebo for use before intercourse twice weekly for 1 month. For a second month, the alternate treatment was given. Main Outcome Measures., Ratings were performed using the patient-rated Arizona Sexual Experiences Scale for females and the clinician-rated Sexual Function Questionnaire (SFQ-V1). Results., Ten patients completed the study. On the five-item self-report Arizona, the item "How easily are you aroused?" was significantly improved on testosterone gel vs. placebo, P = 0.03. There were similar trends on the physician-rated SFQ-V1 "arousal,sensation" cluster. Conclusions., These preliminary results suggest that testosterone gel given prn before intercourse has effects on sexual arousal, and further research is needed to define dosage and time schedule to optimize this effect and determine its clinical relevance. Chudakov B, Ben Zion IZ, and Belmaker RH. Transdermal testosterone gel prn application for hypoactive sexual desire disorder in premenopausal women: A controlled pilot study of the effects on the Arizona Sexual Experiences Scale for females and Sexual Function Questionnaire. J Sex Med 2007;4:204,208. [source] Diabetic rat testes: morphological and functional alterationsANDROLOGIA, Issue 6 2009G. Ricci Summary Reproductive dysfunction is a consequence of diabetes, but the underlying mechanisms are poorly understood. This study investigated the histological and molecular alterations in the testes of rats injected with streptozotocin at prepuperal (SPI rats) and adult age (SAI rats) to understand whether diabetes affects testicular tissue with different severity depending on the age in which this pathological condition starts. The testes of diabetic animals showed frequent abnormal histology, and seminiferous epithelium cytoarchitecture appeared altered as well as the occludin distribution pattern. The early occurrence of diabetes increased the percentage of animals with high number of damaged tubules. The interstitial compartment of the testes was clearly hypertrophic in several portions of the organs both in SPI and SAI rats. Interestingly, fully developed Leydig cells were present in all the treated animals although abnormally distributed. Besides the above-described damages, we found a similar decrease in plasma testosterone levels both in SPI and SAI rats. Oxidative stress (OS) is involved in the pathogenesis of various diabetic complications, and in our experimental models we found that manganese superoxide dismutase was reduced in diabetic animals. We conclude that in STZ-induced diabetes, the altered spermatogenesis, more severe in SPI animals, is possibly due to the effect of OS on Leydig cell function which could cause the testosterone decrease responsible for the alterations found in the seminiferous epithelium of diabetic animals. [source] Chronic immobilization-induced stress increases plasma testosterone and delays testicular maturation in pubertal ratsANDROLOGIA, Issue 1 2000S. A. Almeida Summary. We investigated whether chronic stress, applied from prepuberty to early puberty, interferes with the spermatogenic and androgenic testicular functions. Male pubertal rats (40 days old) were immobilized 6 h per day for 15 days. Plasma concentrations of corticosterone, prolactin and testosterone were significantly augmented following immobilization, whereas plasma luteinizing hormone decreased and follicle-stimulating hormone was not altered. Acute immobilization (5 min) increased prolactin and testosterone levels in control rats but caused a significantly higher increase in these hormones when superimposed on chronic stress. A lower extent of testicular maturation was observed in pubertal rats immobilized from prepuberty. [source] Dexamethasone administration inhibits skeletal muscle expression of the androgen receptor and IGF-1 , implications for steroid-induced myopathyCLINICAL ENDOCRINOLOGY, Issue 1 2010Warrick J. Inder Summary Context, Glucocorticoids are a well-recognized cause of muscle weakness. The early effects of glucocorticoids on skeletal muscle (SkM) androgen and IGF-1 pathways have not been previously investigated in human subjects. Objective, To determine if administration of the potent glucocorticoid dexamethasone down-regulates SkM androgen receptor and the IGF-1 signalling pathway. Methods and subjects, Twenty-four subjects (12 men and 12 women), including 12 with type 2 diabetes and 12 nondiabetics were enrolled. Venous blood sampling and biopsy of vastus lateralis were performed before and after administration of oral dexamethasone 4 mg/day for 4 days. Main outcome measures, Changes in plasma testosterone and IGF-1, SkM androgen receptor mRNA, SkM IGF-1mRNA and SkM IGF-1 receptor mRNA by quantitative RT-PCR after dexamethasone. Results, Relative expression of SkM androgen receptor was similar in male (1·63 ± 0·37) vs. female (1·57 ± 0·30) subjects, despite the significant difference in plasma testosterone levels. Plasma IGF-1 and SkM expression of IGF-1 and IGF-1 receptor were also similar between males and females. Following dexamethasone, there was a significant down-regulation of SkM androgen receptor (1·60 ± 0·23 vs. 1·11 ± 0·16, P < 0·05) and IGF-1 (1·72 ± 0·29 vs. 1·06 ± 0·14, P < 0·05) mRNA, but no change in expression of the IGF-1 receptor. Plasma testosterone fell significantly in both sexes (male: 15·0 ± 1·3 vs. 11·3 ± 1·2 nmol/l, P < 0·01, female: 1·8 ± 0·5 vs. 0·5 ± 0·1 nmol/l, P < 0·05). Conclusions, Exogenous steroid excess results in relative androgen deficiency at two levels, reduced circulating testosterone and SkM androgen receptor mRNA, along with reduced SkM IGF-1 mRNA. These defects may contribute to the development of steroid-induced myopathy. [source] | ||||||||||||||||