An ocular capacity to promote photoperiodic testicular growth in the quail

1983 ◽  
Vol 96 (1) ◽  
pp. 85-90 ◽  
Author(s):  
J. D. Baylé ◽  
J. Oliver ◽  
B. Sicard

Disk-shaped, 0·6 × 0·2 mm pellets of radioluminous material were inserted in the anterior chamber of the eyes of sexually immature male quail on short daylengths. Two weeks later testicular weights and plasma testosterone levels were significantly increased compared with controls. The effectiveness of the ocular implants varied according to the spectrum of emission of the radioluminous material. Sectioning of the optic nerve suppressed all gonadal response to retinal photostimulation.

1971 ◽  
Vol 68 (3) ◽  
pp. 576-584 ◽  
Author(s):  
K. O. Nilsson ◽  
B. Hökfelt

ABSTRACT Metyrapone was administered either orally, 750 mg every four h, in a total of six doses, or intravenously 30 mg per kg body weight as a four h infusion. In three males with normal endocrine functions, metyrapone given orally or intravenously induced a fall in plasma testosterone and an elevation of androstenedione within 2–8 h. When metyrapone was administered to a patient given dexamethasone to suppress endogenous ACTH production, the androstenedione levels did not alter whereas the testosterone levels showed a slight, transient decrease. In two normal females metyrapone administration was followed by a marked increase in plasma androstenedione whereas testosterone showed only a minor, gradual increase. In one male patient with Addison's disease the basal plasma testosterone was normal whereas the level of androstenedione was low. Following metyrapone intravenously, there was a slight suppression of plasma testosterone but no change in the androstenedione concentration. In one patient with primary hypogonadism, two with secondary hypogonadism and two with Klinefelter's syndrome the plasma testosterone was low under basal conditions and did not change following metyrapone. Basal plasma androstenedione was within the range for normal males and increased markedly following metyrapone in all the cases.


1981 ◽  
Vol 96 (2) ◽  
pp. 273-280 ◽  
Author(s):  
Mridula Chowdhury ◽  
Robert Tcholakian ◽  
Emil Steinberger

Abstract. It has been suggested that treatment of intact male rats with oestradiol benzoate (OeB) causes an interference with testosterone (T) production by the testes by a direct inhibitory effect on steroidogenesis. To test this hypothesis, different doses (5, 10 or 25 IU) of hCG were administered concomitantly with 50 μg of OeB to adult intact or hypophysectomized male rats. The testicular and plasma testosterone, and serum hCG levels were determined. The sex accessory weights were recorded. In the intact OeB-treated group of animals, hCG stimulated both the secondary sex organs and plasma testosterone levels above the intact control group. However, in hypophysectomized animals, although plasma testosterone levels increased above that of intact controls, their secondary sex organ weights did not. Moreover, inspite of high circulating hCG levels, the testicular testosterone content and concentration remained suppressed in OeB-treated animals. The reason for such dichotomy of hCG action on OeB-treated animals is not clear at present.


2005 ◽  
Vol 12 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Ilma Simoni Brum ◽  
Poli Mara Spritzer ◽  
Franyoise Paris ◽  
Maria Augusta Maturana ◽  
Franyoise Audran ◽  
...  

1991 ◽  
Vol 124 (4) ◽  
pp. 399-404 ◽  
Author(s):  
Wieland Kiess ◽  
Linda L. Liu ◽  
Nicholas R. Hall

Abstract. Sex-related differences in immune responsiveness are mediated at least in part by sex steroid hormones. Lymphocyte subset distribution in peripheral blood and natural killer cell function both have been reported to be under hormonal control. In order to gain more insight into sex steroid hormone action on the immune system, we have measured the lymphocyte subset distribution and natural killer cell activity in 18 men with idiopathic hypogonadotropic hypogonadism before treatment, and after hormonal treatment had normalized plasma testosterone levels. In untreated patients, the mean plasma testosterone concentrations were significantly lower than those in the treated men (3.0 ± 0.5 nmol/l vs 16 ± 1.7 nmol/l, p < 0.001). The percentage of peripheral CD3+ lymphocytes, CD8+ cells, the CD4+/CD8+ ratio, and the natural killer cell activity of peripheral mononuclear cells measured in a 51Cr release assay against target K 562 cells did not differ between patients with idiopathic hypogonadotropic hypogonadism and healthy adults, and most importantly, did not change during hormonal treatment which normalized plasma testosterone levels in the patients. In contrast, the percentage of peripheral CD4+ cells was significantly higher in untreated patients compared with normal adult subjects or patients with idiopathic hypogonadotropic hypogonadism after hormonal treatment that resulted in normal plasma testosterone levels (53 ± 2 vs 47 ± 2, p < 0.05). It should be noted that the percentage of peripheral CD 16+ cells was significantly lower in untreated men with low plasma testosterone levels than in normal controls. The percentage of CD16+ cells in peripheral venous blood rose significantly after hormonal treatment restored plasma testosterone levels to normal (6 ± 1 vs 11 ± 1, p < 0.001). In addition, the percentage of peripheral CD16+ cells correlated significantly with the plasma testosterone levels measured in men with idiopathic hypogonadotropic hypogonadism (r = 0.534, p < 0.001). In conclusion, both the percentage of peripheral CD4+ cells (T-helper lymphocytes) and peripheral CD16+ cells (non-T-non-B cells) are related to the plasma testosterone levels in men with idiopathic hypogonadotropic hypogonadism. These data suggest that in vivo human immune cells are under the regulatory influence of endogenous sex steroids.


1991 ◽  
Vol 6 (1-2) ◽  
pp. 185-191 ◽  
Author(s):  
P.S.P. Gupta ◽  
P.C. Sanwal ◽  
V.P. Varshney

Oecologia ◽  
2021 ◽  
Author(s):  
Martin Těšický ◽  
Tereza Krajzingrová ◽  
Jiří Eliáš ◽  
Hana Velová ◽  
Jana Svobodová ◽  
...  

1965 ◽  
Vol 50 (1) ◽  
pp. 51-54 ◽  
Author(s):  
Enrico Forchielli ◽  
Govind S. Rao ◽  
Inder R. Sarda ◽  
Norman B. Gibree ◽  
Peter E. Pochi ◽  
...  

ABSTRACT The daily oral administration of one mg of ethinyloestradiol to normal men decreased the mean plasma testosterone from 0.84 ± 0.07 μg per 100 ml to 0.20 ± 0.04 in 21 trials and decreased the urinary testosterone from 63 ± 1.1 μg per day to 8 ± 0.3 in 16 trials.


2012 ◽  
Vol 20 (1) ◽  
pp. 53-64 ◽  
Author(s):  
Joanna M Day ◽  
Paul A Foster ◽  
Helena J Tutill ◽  
Fabien Schmidlin ◽  
Christopher M Sharland ◽  
...  

17β-Hydroxysteroid dehydrogenases (17β-HSDs) catalyse the 17-position reduction/oxidation of steroids. 17β-HSD type 3 (17β-HSD3) catalyses the reduction of the weakly androgenic androstenedione (adione) to testosterone, suggesting that specific inhibitors of 17β-HSD3 may have a role in the treatment of hormone-dependent prostate cancer and benign prostate hyperplasia. STX2171 is a novel selective non-steroidal 17β-HSD3 inhibitor with an IC50 of ∼200 nM in a whole-cell assay. It inhibits adione-stimulated proliferation of 17β-HSD3-expressing androgen receptor-positive LNCaP(HSD3) prostate cancer cells in vitro. An androgen-stimulated LNCaP(HSD3) xenograft proof-of-concept model was developed to study the efficacies of STX2171 and a more established 17β-HSD3 inhibitor, STX1383 (SCH-451659, Schering-Plough), in vivo. Castrated male MF-1 mice were inoculated s.c. with 1×107 cells 24 h after an initial daily dose of testosterone propionate (TP) or vehicle. After 4 weeks, tumours had not developed in vehicle-dosed mice, but were present in 50% of those mice given TP. One week after switching the stimulus to adione, mice were dosed additionally with the vehicle or inhibitor for a further 4 weeks. Both TP and adione efficiently stimulated tumour growth and increased plasma testosterone levels; however, in the presence of either 17β-HSD3 inhibitor, adione-dependent tumour growth was significantly inhibited and plasma testosterone levels reduced. Mouse body weights were unaffected. Both inhibitors also significantly lowered plasma testosterone levels in intact mice. In conclusion, STX2171 and STX1383 significantly lower plasma testosterone levels and inhibit androgen-dependent tumour growth in vivo, indicating that 17β-HSD3 inhibitors may have application in the treatment of hormone-dependent prostate cancer.


2017 ◽  
pp. 695-703 ◽  
Author(s):  
J. BABKOVÁ DURDIAKOVÁ ◽  
P. CELEC ◽  
I. KOBOROVÁ ◽  
T. SEDLÁČKOVÁ ◽  
G. MINÁRIK ◽  
...  

Testosterone has been widely investigated in associations with many aspects of social interactions, emotions and behavior. No research has been conducted on its contribution to the variability of love styles in human. The aim of this paper was to uncover the possible relationship between not only the actual plasma testosterone levels, but also the prenatal testosterone level (expressed as 2D:4D ratio) and the sensitivity of androgen receptor and love typology in young healthy men. There are six love styles which are primary including Eros (passionate romantic love), Ludus (playful) and Storge (friendly) and secondary love consisting of Mania (obsessive), Pragma (practical realistic) and Agape (altruistic). Our results pointed out that low testosterone concentrations are associated with higher score for Eros, Ludus, Pragma, Mania love style. No significant association was proved for other tested parameters of androgenicity (2D:4D, sensitivity of androgen receptor) and love style after correction was applied. Different attitudes and behavior in relationships do have a biological foundation related to endogenous testosterone levels in plasma. Future studies should address questions about the family and social background of participants to differentiate here between moral rules or/and social-conventional rules.


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