Peripheral Testosterone Concentrations Research Articles

Effect of Acute Melatonin Injection on Metabolomic and Testicular Artery Hemodynamic Changes and Circulating Hormones in Shiba Goats under Sub-Tropical Environmental Conditions.

The beneficial effects of melatonin were investigated to mitigate various detrimental effects and toxicity on reproductive performance. The present study aimed, for the first time, to explore the effect of intravenous melatonin injection on testicular artery hemodynamics (TH) and metabolomic changes, reproductive hormones in heat-stressed bucks. Ten bucks were randomly split into two groups (five each): (1) the melatonin group, treated with a single intravenous dose of melatonin solution containing 10 mg melatonin each, and (2) the control group, which was treated with 10 mL of the vehicle without melatonin. Changes in the TH at the level of the supra testicular artery (STA) were assessed by triplex ultrasonography just before (0 h) and at 0.5, 2, 7, 24, and 168 h after melatonin or vehicle administration. Doppler velocity parameters of peak systolic velocity (PSV; cm/s), end-diastolic velocity (EDV; cm/s), and time average maximum velocity (TAMAX; cm/s) were measured. Doppler indices (resistive index; RI and pulsatility index; PI), systole/diastole (S/D) ratio and total arterial blood flow volume (TABFV; ml/minute) were measured. Peripheral concentrations of FSH, LH, inhibin, melatonin, testosterone (T), estradiol (E2), and cortisol were measured just before injection (0 h) and at 0.5, 2, 7, and 24 h and daily up to day 7 post administration in both groups. Results revealed reductions in the RI values and increases in the TABFV in the melatonin group compared to the control one, especially 2 h after administration. Significant increases in concentrations of FSH, T, E2, and melatonin and decreases in cortisol and inhibin in the melatonin group compared to the control one. Plasma metabolomic analysis at 2 h indicated the up-regulation of L-glutamine, L-arginine, sorbitol, D-glucose, ascorbic acid, and ornithine and the down-regulation of D-xylose, D-arabitol, ribitol, and oleic acid in the melatonin versus the control group. In conclusion, acute administration of melatonin (10 mg IV) enhanced testicular artery blood flow and plasma reproductive hormones in the Shiba goat under heat-stress circumstances.

Concentrations of testosterone, estrone and estrone sulfate in peripheral blood of donkey stallions in relation to season

To assess testicular endocrine function in the male donkey (Equus asinus) during the course of the year. In 5 miniature and 4 standard donkey stallions, peripheral blood concentrations of testosterone (T), estrone (E1) and estrone sulfate (E1S) were determined using radioimmunoassay. There was a highly significant influence of the season (p < 0.0001) on the course of all 3 steroids. Values were low in November until January and high in April, May and June. As delineated by the measurement of E1 the breed also had an effect on the expression of seasonality. Mean T concentration (X̅g × SF ± 1) was 1.58 × 1.20 ± 1 ng/ml, values ranged between 0.39 and 5.95 ng/ml, which is approximately double the plasma T concentrations observed in horse stallions. As in horse stallions, E1 levels were only slightly above the detection limit of the assay (0.10-0.17 ng/ml). Mean E1S concentration amounted to 0.91 ± 0.23 ng/ml, values ranged between 0.34-1.36 ng/ml and taking peak levels into account measured approximately 300-fold lower than in the horse stallion. The data obtained confirm that the donkey belongs to the group of long day breeders. Irrespective of the close phylogenetical relationship the course of E1S concentrations reveals distinct differences between horse and donkey. Even between closely related species established reference values for sex steroids cannot be transferred without verification.

Sexual maturity and fertility-related measures in young Nellore bulls receiving long-term dietary supplementation with rumen-protected polyunsaturated fatty acids

The objective of this study was to evaluate the effects of long-term supplementation with rumen-protected fatty acids (FA) on growth and reproductive parameters of young Nellore bulls in a grazing regime. Forty-eight young bulls were distributed into two groups: FA (supplemented with rumen-protected polyunsaturated FA); and control (control fat-free supplement). The animals were supplemented from 14.3 to 24.6 months of age and growth and reproductive parameters were evaluated at 28-day intervals. The semen was cryopreserved in the last collection and fresh and post-thaw semen samples were evaluated. Feeding FA did not affect (P > 0.05) growth, reproductive parameters (scrotal circumference, sperm concentration per mL of ejaculate, percentage of sperm defects, sperm quality and fertility in vitro), or testicular ultrasonographic characteristics. However, thawed semen from bulls fed FA exhibited better quality (P < 0.05) than control semen for the following parameters evaluated by computer-assisted sperm analysis: average path velocity [μm/s: 90.48 vs. 79.66 post-thaw and 74.81 vs. 72.80 post-rapid thermoresistance test (TRT)], straight-line velocity (μm/s: 72.37 vs. 65.20 post-thaw and 64.96 vs. 63.25 post-TRT), and curvilinear velocity (μm/s: 148.44 vs. 131.31 post-thaw and 115.68 vs. 113.35 post-TRT). In addition, feeding FA increased peripheral concentrations of testosterone, leptin, total cholesterol and high-density lipoprotein. In conclusion, the increase in testosterone concentrations in bulls fed FA was not related to variations in growth parameters and sexual maturity. In addition, post-thawing sperm velocities were enhanced by diet, however, such increases were not related to better in vitro embryo production rates.

Age-related changes in the gross anatomy of the reproductive organs, and associated steroid hormone profiles in male and female guinea fowls (Numida meleagris)

Owing to the paucity of information on the reproductive biology of guinea fowls, a study involving a total of 132 birds was conducted, and this documented the developmental changes in the gross anatomy of the reproductive organs of males and females from hatching until 32 weeks of age (WOA), and associated steroid hormone changes. Testicular anatomical biometric traits increased significantly (p < 0.0001) from 8 WOA, and stabilised between 16 and 20 WOA, while peripheral testosterone concentration peaked at 20 WOA. Correlations among all testicular biometric characteristics were strong and positive (p < 0.0001). Similarly peripheral testosterone concentrations strongly (p < 0.01) and positively correlated with all the testicular anatomical biometric traits. In the female guinea fowl, the ovary and oviduct were discernible and measurable at hatching. Significant (p < 0.0001) increases were seen in ovarian and relative ovarian weights, and oviducal weights and lengths between 24 and 28 WOA. Plasma 17β-oestradiol decreased gradually to a very minimum at 16 WOA, and then began to increase gradually until 28 WOA when it plateaued. Peripheral progesterone concentrations on the other hand increased gradually from 4 WOA and peaked at 12 WOA, and then fluctuated considerably thereafter. Correlations among ovarian/oviducal anatomical parameters were strong (p < 0.0001) and positive. Similarly, peripheral oestradiol concentrations strongly (p < 0.0001) and positively correlated with all ovarian/oviducal anatomical parameters. Testicular anatomical biometric traits stabilised between 16 and 20 WOA, coinciding with peak peripheral testosterone concentrations, while ovarian/oviducal parameters recorded huge increases between 24 and 28 WOA, and may be under the influence of oestradiol.

Developmental changes in the histological structure of the testes, and testosterone profiles in male guinea fowls (Numida meleagris)

Owing to the paucity of information on the reproductive biology of guinea fowls, a study involving a total of 66 males was conducted, and documented the developmental changes in histological structure of the testes of guinea cocks from hatching until adulthood. Changes in testosterone synthesis during sexual development were also determined. Age-related changes were analysed using univariate analysis for completely randomised design and means separated using Tukey's test/Kruskal-Wallis test and medians separated by Mann-Whitney U test. Total germ cell population per testis and testicular histological morphometric parameters increased significantly (p < 0.0001) from 12 weeks of age (WOA), and stabilized between 20 and 24 WOA. Peripheral testosterone concentrations increased gradually from 4 WOA, and peaked at 20 WOA. Correlations among all the testicular morphometric parameters were positive and highly significant (p < 0.01). Similarly, significant (p < 0.05) positive correlations existed between testicular weight and testicular sperm production, tubular diameter, Sertoli cell population, tubular length and peripheral testosterone concentration. Testicular sperm production was positively correlated with meiotic index (p < 0.01) and round spermatids population (p < 0.05). The correlations between peripheral testosterone concentrations, tubular diameter and Sertoli efficiency were also significant (p < 0.05) and positive. Testicular morphometric parameters stabilized between 20 and 24 WOA, while peripheral testosterone concentrations showed two patterns of secretion, initial and final phases of increasing and decreasing testosterone secretions, respectively, and may be implicated in the development of histological structures of the testes and spermatogenesis.

Effects of season on the reproductive organ and plasma testosterone concentrations in guinea cocks (Numida meleagris)

The physiological basis of seasonal breeding in the guinea fowl (Numida meleagris) still remains unknown, despite the socioeconomic importance of these birds, particularly in Ghana. A study involving a total of 50 local guinea cocks was conducted, and documented gross anatomical and histological differences in the reproductive organs of breeding and non-breeding male guinea fowls. The study also compared peripheral testosterone concentrations in breeding and non-breeding cocks. Seasonal differences in variables measured were determined using two-tailed t-test/Mann-Whitney U-test. All comparisons were made at 5% level of significance. Breeding males had significantly (P = 0.000) higher anatomical biometric parameters than their non-breeding counterparts. Also, breeding birds had thicker (P = 0.000) phalli than their non-breeding counterparts. Histologically, regressing testis was characterized by the presence of sloughed off cells and increased debris in the tubular lumen and within the excurrent duct system, collapsed tubules and reduction in tubular lumen. Germ and Sertoli cell populations and nuclear diameters and actual seminiferous tubular diameter and length in regressing testes were significantly (P = 0.000) lower than in active testes. Leydig cell nuclear diameters and populations were also significantly (P = 0.000) reduced. Relative volume of seminiferous tubules in the testis, testicular sperm production/mg testis and per testis and peripheral testosterone concentrations were all higher (P < 0.05) in breeding than non-breeding testis. The ducts in the epididymal region also saw significant (P < 0.05) reductions in luminal diameters in non-breeding birds. Significant regression in anatomical and histological structures of the guinea cock reproductive tract occurred during the non-breeding season, and lower peripheral testosterone concentrations may be responsible for this phenomenon.

Growth, testis size, spermatogenesis, semen parameters and seminal plasma and sperm membrane protein profile during the reproductive development of male goats supplemented with de-oiled castor cake.

The present study was conducted to evaluate the effect of de-oiled castor cake on reproductive traits of crossbreed goats. Fourteen males were grouped into two lots (n = 7/group), as described: group without de-oiled castor cake (WCC) and group fed with de-oiled castor cake (CC). Goats received two diets containing a mixture of Bermudagrass hay and concentrates with the same energy (73% total digestive nutrients) and protein content (15% crude protein) during 150 days, corresponding to ages from 40 (puberty) to 60 weeks. Blood plasma concentrations of urea, albumin, lactate dehydrogenase, creatinine, alanine aminotransferase and testosterone were determined. We also evaluated scrotal circumference, sperm parameters, quantitative aspects of spermatogenesis and daily sperm production (DSP), as well as the proteome of seminal plasma and sperm membrane. Seminal fluid and sperm proteins were analyzed by 2D SDS-PAGE and mass spectrometry. After 150 days of castor cake feeding, animals had no changes in the biochemical composition of blood plasma, suggesting the absence of intoxication by ingestion of ricin. There were no alterations in dry mater intake, weight gain, testis size, peripheral concentrations of testosterone, sperm concentration, motility and morphology. Sertoli and germ cell populations in the testis and DSP were not affected either. However, there were significant variations in the expression of five seminal plasma proteins and four sperm membrane proteins. In conclusion, the replacement of soybean meal by castor cake (with ricin concentrations of 50mg/kg) did not interfere with the growth and core reproductive development of male goats. However, the diet with ricin altered the expression of certain seminal plasma and sperm membrane proteins, which play roles in sperm function and fertilization. Lower expression of these proteins may impair the ricin-fed animals to perform as high-fertility sires.

Testis size, peripheral concentrations of testosterone, semen criteria and Sertoli and germ cell numbers in Nelore bulls

Conduziu-se o presente estudo com o objetivo de avaliar as associações entre biometria testicular, testosterona, parâmetros seminais e aspectos da espermatogênese em touros Nelore (n = 28). Avaliou- se os testículos dos 10 aos 29 meses de idade. Os touros foram tratados com GnRH (12 a 21 meses) e amostras de sêmen coletadas (25 a 29 meses). Aos 30 meses, os animais foram abatidos. Correlações foram consideradas significativas quando p &lt; 0.05. Concentrações elevadas de testosterona basal ocorreram aos 18 meses, indicativo da puberdade dos touros. Aos 30 meses, os túbulos seminíferos representaram 77,9 ± 3,8% do parênquima testicular e quantificou-se 33,6 ± 8,4 espermátides arredondadas/espermatogônia A1/secção tubular, referente a 47,5% de degeneração celular durante a espermatogênese. Aos 30 meses, peso testicular correlacionou-se com o número de células de Sertoli/ testículo (r = 0,77) e espermátides arredondadas/seção tubular, célula de Sertoli e espermatogônia A1 (r = 0,50 – 0,60). A circunferência escrotal (CE) entre 10 e 29 meses correlacionou-se com a percentagem de túbulos com espermátides (r = 0,42 – 0,59) e número de espermatogônias e espermátides arredondadas/ célula de Sertoli (r = 0,49 – 0,68). Detectou-se correlações entre peso epididimário e número de células de Sertoli/testículo e espermátides arredondadas/célula de Sertoli e espermatogônia A1 (r = 0,51 – 0,61). Testosterona pós-GnRH (17 aos 21 meses) apresentou relação com a CE entre 14 e 29 meses (r = 0,48 – 0,60), peso testicular e epididimário (r = 0,41 – 0,64) e parâmetros da espermatogênese (r = 0,44 – 0,58). Motilidade e vigor espermático (25 aos 29 meses) correlacionaram-se com o número de túbulos com espermátides (r = 0,42 – 0,59) e testosterona pós-GnRH aos 12, 13 e 18 meses (r = 0,46 – 0,57). Portanto, a biometria testicular durante e após a ocorrência dos níveis concentrações elevadas de testosterona é um indicador dos parâmetros quantitativos da espermatogênese em touros pós-púberes.

Suppression of fertility in adult cats.

Cats are animals with highly efficient reproduction, clearly pointing to a need for suppression of fertility. Although surgical contraception is highly effective, it is not always the method of choice. This is predominantly because it is cost-intensive, time-consuming and irreversible, with the latter being of major importance for cat breeders. This article reviews the use of progestins, scleroting agents, immunocontraception, melatonin, GnRH antagonists and finally, GnRH agonists, in adult male and female cats in detail, according to the present state of the art. By now, various scientific and clinical options are available for the suppression of fertility in adult cats and the decision as to which should be chosen - independent of the legal registration of any state - depends on different facts: (i) feral or privately owned animal? (ii) temporary or permanent suppression of fertility wanted/needed? (iii) sex of the animal? New effective and available methods for hormonal contraception include melatonin implants for short-term post ponement of oestrus in adult queens and slow-release GnRH-agonist implants containing deslorelin (Suprelorin(®) ) for short- and long-term contraception in male and female companion and breeding cats.

Seasonal Changes in Spermatogenesis and Peripheral Testosterone Concentration in Raccoons (&lt;i&gt;Procyon lotor&lt;/i&gt;) in Hokkaido

Feral raccoons (Procyon lotor) have been increasing in number since 1979 and are currently subject to pest control in Hokkaido. One of the reasons for the increase in numbers is thought to be the high reproductive potential of raccoons, but little is known about their reproduction. The main aim of this study was to clarify seasonal changes in spermatogenesis and peripheral testosterone concentration of raccoons in Hokkaido. In the present study, external characteristics and histology of the testis and epididymis and the plasma testosterone concentration were investigated in 68 feral, male raccoons culled for pest control and once a month in one live, captive male. The feral males exhibited seasonal changes in spermatogenesis, showing active spermatogenesis in autumn, winter and spring (October-June) with noted spermatogenesis and inactive spermatogenesis in summer (July-September) with lower mean levels of spermatozoa in the cauda epididymis. Even in the inactive period, spermatozoa were observed in about half of the individuals (14/26); therefore, individuals producing spermatozoa existed every month throughout the year. Testosterone concentrations were significantly high in the winter mating season. In the captive male, the testosterone concentrations were low from June to August, and spermatozoa could not be observed from July to September. These results suggest that raccoons exhibit seasonality of reproduction, but the time and duration of spermatogenetic decline varies widely among individuals. This individual variation in the inactive period is a feature of male raccoon reproduction and is unique among seasonally breeding mammals.

The Effect of Season on Semen Characteristics and Freezability in Bos indicus and Bos taurus Bulls in the Southeastern Region of Brazil

The objectives of this study were to evaluate the effects of season in southeast of Brazil comparing genotypes on semen characteristics, freezability and peripheral plasma concentrations of testosterone. Ejaculates of five Bos indicus bulls and six Bos taurus bulls were evaluated over a period of 27 months, which was divided into winter (July, August, September), spring (October, November, December), summer (January, February, March) and autumn (April, May, June). Semen was evaluated according to standard procedures for ejaculate volume, sperm concentration, gross-motility, progressive motility and sperm morphology. After preparing and freezing the ejaculates according to commercial procedures, the straws were stored in liquid N(2) until post-thaw evaluation. Ejaculate volume, sperm concentration, gross-motility, progressive sperm motility, vigor and morphological sperm defects were significantly influenced by season and genotype (p < 0.05). Heat tolerance was better in B. indicus bulls than in B. taurus bulls characterized by lower values of sperm abnormalities throughout the observation period. The highest values were recorded for abnormal heads followed by cytoplasmatic droplets in B. taurus bulls. The proportion of ejaculates which were eliminated before freezing for reasons of bad quality was lower in the B. indicus bulls. Temporal changes in peripheral plasma testosterone concentrations were higher in B. indicus bulls than in B. taurus bulls not revealing seasonal influences. The results of this study show clear genotype differences regarding semen quality. Freezability of B. taurus semen varies considerably throughout the year, leading to a high proportion of eliminated ejaculates. Collecting semen from B. taurus bulls during the summer in an artificial insemination centre may not be profitable.

A study of Serum Steroid Hormones Concentrations Of Pregnant Cows

The objective of present work is to estimated peripheral blood serum concentrations of pregnancyhormones, oestradiol , progesterone and testosterone , in cows . For this purpose 24 Frezain- Holsteincows at different stages of pregnancy the blood samples were taken from jugular veins. The serumwere separated and frozen at – 20 c until analysis. The serum hormones were measured by a specificELISA technique (ELISA Linear Multi Reader). The data were represented Mean + S.D. Progesteronewas high during pregnancy reaching a maximum of 91.94 + 26.09 ng/ml during last thirds (6-8months) of pregnancy , but was below 9.12 + 2.41 ng/ml for several months during the pregnancy.Oestradiol levels varied from 9.0+ 2.89 pg/ml in the first thirds of pregnancy to 282.6 + 48 .514 pg/mlduring the last month of gestation. While testosterone hormone level was low 0.32 + 0.12 ng /mlduring pregnancy. The result indicated that the major sources of hormones appeared to be the 0vary(corpus luteum ) and the uterus (placenta). The ovarian contribution was greater during the first – thirdsof pregnancy than later, whereas that made by the placenta was higher during the last thirds ofpregnancy

Selective venous sampling for androgen‐producing ovarian pathology

Multiple diagnostic modalities may be needed to establish the source of excessive androgen production in women. The role of selective venous catheterization in this process has not been established fully. A study of hyperandrogenaemic subjects and literature review. Four hyperandrogenaemic women and an additional 132 previously reported cases with available testing data and a pathological diagnosis were evaluated. Serum androgens, diagnostic imaging and ovarian venous effluent sampling. Criteria to distinguish ovarian tumours from other ovarian conditions and to localize the lesion(s) were evaluated. Basal peripheral testosterone levels >or= 4.51 nmol/l (>or= 130 ng/dl) discriminated ovarian tumours from benign causes of hyperandrogenism (sensitivity: 93.8%, 95% CI 85.0-98.2; specificity: 77.8%, 95% CI 66.4-86.7). Single lesions produced higher ipsilateral testosterone concentrations (612.6 +/- 162.0 nmol/l; 17 653 +/- 4670 ng/dl) compared to contralateral values (26.4 +/- 5.2 nmol/l; 761 +/- 150 ng/dl). In women with peripheral testosterone >or= 4.51 nmol/l, a right-to-left (R:L) ovarian testosterone ratio >or= 1.44 correctly identified all 18 women with right-sided tumours and misclassified two with bilateral lesions; 12 out of 14 women with left-sided or bilateral lesions had a lower R:L value. When this criterion was combined with a left-to-right (L:R) ovarian testosterone effluent ratio of > 15 to identify left-sided tumours, overall 66% of women were correctly categorized. Peripheral testosterone concentrations identified ovarian androgen-producing tumours, and venous sampling could correctly localize 66% of these, suggesting a role for sampling when imaging studies are not revealing.

Relationships Among Age, Body Weight, Scrotal Circumference, Semen Quality and Peripheral Testosterone and Estradiol Concentrations in Pubertal and Postpubertal Holstein Bulls

In the present study, the correlations among age, body weight, scrotal circumference (SC), semen quality and peripheral testosterone and estradiol-17beta (E(2)) concentrations were investigated in pubertal (n=5) and postpubertal (n=7) groups of Holstein bulls over a 6 week period. There were significant positive correlations (P<0.01) among age, body weight and SC in both groups, and similar significant correlations between sperm motility and SC in pubertal bulls (P<0.01) and between sperm concentration and SC in postpubertal bulls (P<0.05). The sperm motility after collection (P<0.05) and after freezing and thawing (P<0.01) of the postpubertal bulls correlated positively with the E(2) concentration. Estrogen may be important for the function of postpubertal bull testes, in which it may regulate spermatozoa motility in vivo.

Ovarian venous sampling to guide localization and treatment of female hyperandrogenism

Virilization with plasma testosterone levels greater than 150 ng/dl raises the possibility of an ovarian or adrenal tumor. While testosterone-producing adrenal tumors are almost always seen on imaging, ovarian tumors may remain occult. In that case, ovarian venous sampling may identify and localize the source of testosterone excess. We report the results of this technique in four patients. Case reports from a tertiary care center. Ovarian ultrasound (US) and MRI were obtained and used to calculate right (R) and left (L) ovarian volumes (OVs). For ovarian venous sampling, catheters were placed and blood was drawn sequentially and simultaneously from each ovarian vein and a peripheral vein before and every 10 minutes after administration of hCG (2000 or 5000 IU IM). The ratios of ovarian:peripheral testosterone concentrations (O:P Testo) were calculated and the right (R) and left (L) ratios compared. A maximal (max) O:P Testo step-up of 2 or more was considered to localize pathology if the contralateral value was near 1. All four patients presented with virilization and hyperandrogenism (all Testo yr> upper normal range). Plasma inhibin A and/or B levels were measured in 3 patients, and were normal or low. All estradiol levels were normal. There were no ovarian masses on US or MRI. 12-year old Patient 1 presented with precocious puberty but no menarche (plasma testosterone 158 ng/dl). ROV was 24 cm3 and LOV was 23 cm3. The R O:P Testo was 4 and the L O:P Testo was 1. The right ovary was removed and found to be hyperthecotic. A subsequent plasma testosterone level was 46 ng/dl. 18-year old Patient 2 (plasma testosterone 219 ng/dl) had a ROV of 14.1 cm3 and LOV of 9.1 cm3. The O:P Testo was 2.7 on the R at 20 minutes, but anomalous blood flow prevented definitive lateralization. (Left O:P Testo = 1.2.) Retrograde flow from the L kidney descended through the ovarian vein and then crossed via pelvic collateral veins to the R ovarian vein where it ascended normally to join the upper inferior vena cava. Thus, elevated R O:P Testo could represent testosterone secretion by either ovary. Given these considerations, surgery was not recommended, and the patient continues to be followed. 62-year old Patient 3 (plasma testosterone 876 ng/dl) had ROV of 2.6 cm3 and LOV 2.8 cm3. Ten minutes after hCG stimulation the R O:P Testo was 1.5 and the L O:P Testo was 1.8. Histologic examination after bilateral oophorectomy revealed a Sertoli-Leydig tumor on the left ovary and cortical stromal hyperplasia of the right. The post-operative plasma testosterone level was 20 ng/dl. 71-year old Patient 4 (plasma testosterone 216 ng/dl) had ROV of 1.7 cm3 and LOV of 1.5 cm3. The max R O:P Testo was 3.6 at 10 minutes post-hCG and the max L O:P Testo was 0.9 at time 0. After bilateral oophorectomy (based on surgical findings) histologic examination showed bilateral hyperthecosis. The plasma testosterone level was 52 ng/dl after surgery. Ovarian venous sampling contributed to the successful identification and removal of an ovarian testosterone source in three patients with unilateral or bilateral hyperthecosis, or with a Sertoli-Leydig tumor and hyperplasia. A fourth patient did not have surgery. Thus, ovarian venous sampling may be a helpful guide to treatment decisions in cases of female hyperandrogenism.

Salivary Hormone Concentrations in Mothers and Fathers Becoming Parents Are Not Correlated

A time- and date-matched set of saliva samples ( N = 229) from nine couples first expecting, and then caring for, their first child were used to test whether hormone changes in the father could be predicted by the hormonal status of the mother. Testosterone, cortisol, and estradiol were quantified from saliva. Neither testosterone nor estradiol concentration was correlated within couples before or after the birth, although there was a positive correlation for cortisol concentration in the mother and father before the birth. As the hormone that might be influenced by chemical signals, that already played a similar role in men and women, and that had been empirically linked to paternal behavior, cortisol concentration was also compared with sex steroid concentrations. The mother's cortisol concentration was positively correlated to the father's testosterone concentration, and the mother's testosterone concentration was positively correlated with the father's cortisol concentration. However, both effects were similar in magnitude to the cortisol to cortisol correlation, and all could parsimoniously be explained by similar responses to a shared environment. Thus, this analysis rejects parallels in peripheral hormone concentrations of estradiol, testosterone, and cortisol in mothers and fathers. However, the available data were not able to test or reject hypotheses about local neuroendocrine homology, nor to control for masking effects of other hormonal demands on men and women, nor to determine the relative importance of shared environment versus mother-father signaling.

Desenvolvimento ponderal e testicular, concentrações periféricas de testosterona e características de abate em touros da raça Nelore

Um experimento foi conduzido com o objetivo de avaliar o desenvolvimento ponderal e testicular, as concentrações periféricas de testosterona (T) e características de abate, dos 10 aos 30 meses de idade, em tourinhos da raça Nelore (n=27). Entre 11 e 21 meses, os animais foram tratados com GnRH e amostras de sangue, coletadas 0, 1,5 e 3,0 horas depois. Aos 30 meses, os animais foram abatidos. O peso vivo (PV) dos animais variou de 195,2 ± 3,8 kg a 439,1 ± 8,1 kg entre 10 e 30 meses e o rendimento de carcaça foi de 55,4 ± 2,3%. Os pesos dos testículos (PT) e do epidídimo (PE) aos 30 meses foram 160,9 ± 7,7 g e 20,4 ± 0,62 g, respectivamente. As concentrações de T apresentaram crescimento maior entre 16 e 18 meses e o tratamento com GnRH ocasionou aumentos nos níveis de T em todas as idades. As concentrações de testosterona estimuladas com GnRH estiveram associadas às concentrações basais (r = 0,41 a 0,63). Houve correlações entre PV e circunferência escrotal (CE) em todas as idades (r = 0,41 a 0,70). O peso corporal entre 10 e 30 meses apresentou correlações com PT (r = 0,48 a 0,62) e PE (r = 0,48 a 0,73) aos 30 meses e animais com maior peso de carcaça também tiveram maiores pesos testicular (r = 0,45) e epididimal (r = 0,63). Houve correlações entre PV (10 e 30 meses) e peso da carcaça (r = 0,65 a 0,93), mas o rendimento de carcaça não apresentou relação com CE, PT, PV ou níveis de testosterona. Foram significativas também as correlações entre a CE aos 30 meses e a CE avaliada entre 10 e 25 meses (r = 0,51 a 0,89). Portanto, medidas testiculares são potenciais indicadores do desenvolvimento ponderal e das características de abate na fase adulta.

Cavernous and systemic testosterone plasma levels during different penile conditions in healthy males and patients with erectile dysfunction

Objectives. To determine the testosterone plasma levels in the cavernous and peripheral blood taken during different penile conditions from patients with erectile dysfunction (ED) and to evaluate whether these courses are different from those detected in the blood of healthy males. Although the determination of the systemic testosterone concentration (TC) has been fairly well established in the diagnostic workup of ED, the exact role of testosterone in adult male sexual function remains unclear. Methods. Blood samples were drawn simultaneously from the corpus cavernosum and cubital vein of 54 healthy males with normal erectile function and 46 patients with ED during the penile stages of flaccidity, tumescence, rigidity (reached by the healthy males only), and detumescence. Tumescence and rigidity were induced by audiovisual and tactile stimulation. The TC was determined by means of a radioimmunoassay. Results. In the flaccid phase, the TC in the cavernous blood taken from the healthy volunteers was 2.9 ± 1.2 ng/mL. The TC significantly increased during tumescence (4.3 ± 1.3 ng/mL) and rigidity (4.4 ± 1.4 ng/mL), P <0.001. In the detumescence phase, the TC decreased appreciably to 3.5 ± 1.4 ng/mL. In the systemic blood, the increase from flaccidity (4.1 ± 1.1 ng/mL) to tumescence (4.4 ± 1.4 ng/mL) was found to be less pronounced but, nevertheless, significant ( P = 0.001). No further increase was detected during rigidity. From rigidity to detumescence, the systemic TC dropped to 4.1 ± 1.2 ng/mL. In the patients with ED, the mean increase in systemic and cavernous testosterone levels from flaccidity (cubital vein 3.0 ± 1.0 ng/mL, corpus cavernosum 2.6 ± 1.0 ng/mL) to tumescence (cubital vein 3.2 ± 1.1 ng/mL, corpus cavernosum 3.0 ± 1.0 ng/mL) was less pronounced. Nevertheless, the course of testosterone detected in the systemic and cavernous plasma of the patients during flaccidity, tumescence, and detumescence resembled that registered in the healthy controls. In the flaccid phase, the mean cavernous TC in the healthy subjects was found to be 30% lower than the level in the peripheral blood; in the patients with ED, this difference was only 13%. Conclusions. In the healthy males, the penile erection was accompanied by an increase in the cavernous and peripheral TC. The difference between the peripheral and cavernous TC in the healthy subjects and patients with ED in the flaccid phase, when the blood flow through the cavernous body is minimized, might be a diagnostic tool to evaluate the amount of bioavailable testosterone, as well as the density of testosterone receptors, in the cavernous smooth musculature.

Absence of Photoperiodic Modulation of Gonadotrophin Secretion in HPD Rams Following Chronic Pulsatile Infusion of GnRH

Hypothalamo-pituitary disconnected Soay rams (HPD rams) were treated chronically with a pulsatile infusion of GnRH (250 ng/2 h) for 10 weeks to reactivate the pituitary-gonadal axis under long days (16L:8D; LD group n=8) and short days (8L:16D, SD group n=8). The aim was to establish whether photoperiod modulates the secretion of gonadotrophins (presumably through the daily melatonin signal) by an action at the level of the pituitary gland. The treatment of the HPD rams with GnRH induced a marked, long-term increase in the peripheral blood concentrations of FSH, LH and testosterone, growth of the testes and reappearance of the androgen-dependent sexual skin colouration. There were parallel changes in the short-term, pulsatile fluctuations in the blood concentrations of LH and FSH, the pituitary responsiveness to GnRH and the testicular responsiveness to a standardized injection of oLH, as observed previously in normal intact rams during reactivation of the reproductive axis induced by a switch from long to short days. There were no significant differences in any of the reproductive parameters between the LD and SD HPD groups, although the blood concentrations of prolactin were significantly higher in the LD group, and GnRH provoked a chronic increase in the blood concentrations of prolactin, particularly in the SD group. Overall, the results support the conclusion that (i) melatonin does not act within the pituitary gland to mediate effects of photoperiod on GnRH-induced gonadotrophin secretion; and (ii) changes in prolactin secretion which result from the local action of melatonin in the pituitary gland do not affect gonadotrophin secretion in the ram.

Seasonality in male Australian cashmere goats: Long term effects of castration and testosterone or oestradiol treatment on changes in LH, FSH and prolactin concentrations, and body growth

Australian cashmere goat bucks exhibit marked seasonal changes in gonadotrophin secretion and growth. We investigated the mechanisms underlying these changes by testing the effects of castration and gonadal steroid replacement in grazing bucks at 29 °S, 153 °E over a period of 2 years. Three year old bucks were either left intact ( n = 6), castrated ( n = 6), or castrated and treated with testosterone propionate ( n = 5) or oestradiol-17β ( n = 5). Oestradiol- 17β (E 2) was provided by 2 subcutaneous Silastic ® implants while testosterone propionate (TP) was provided by implanting four 23.5 mg pellets subcutaneously every 12 weeks. Intact bucks exhibited marked circannual cycles of plasma LH, FSH, prolactin and testosterone concentration, body mass, paired testicular mass and male odour. Castration resulted in long term increases in LH and FSH concentration and abolition of the circannual pattern of change in these hormones without affecting prolactin concentrations. It also reduced the magnitude of seasonal changes in body mass. Treatment of castrates with TP, which produced peripheral concentrations of testosterone in the lower physiological range (mean 1.2 ± 0.08 μg L −1), had no effect on plasma concentrations of LH, FSH or prolactin. On the other hand treatment with E 2, which produced E 2 concentrations in the mid physiological range (mean 12.3 ± 1.08 ng L −1), re-imposed a circannual pattern in plasma LH and FSH, albeit significantly different from that of intact bucks. It had no effect on prolactin concentrations. Treatment with both steroids resulted in growth cycles of intermediate magnitude between those of intact bucks and castrates. We conclude that the circannual cycle of gonadotrophin concentrations in goat bucks is dependent upon the presence of the testis, and suggest that circulating metabolites of testosterone, including oestradiol, are more important than testosterone itself in the maintenance of this cycle. We also suggest that the seasonal growth cycle observed in these bucks is driven by factors other than prevailing nutrition, probably photoperiod, and is mediated by both steroid-dependent and independent mechanisms.