Acute suppression of endogenous teststterone levels by exogenous testosterone in normal men

Fujioka, Minoru; Shinohara, Yoshihiko; Baba, Shigeaki; Irie, Minoru; Inoue, Kazuko

doi:10.1016/0024-3205(87)90681-3

Cited by 13 publications

(8 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The described testosterone effects on the seminiferous tubules in our experiment could be explained by its suppression of FSH and LH (Fujioka et al 1987;Bardin 1989). FSH and LH are both necessary for the completion of spermatogenesis (Awoniji et al 1990;Santulli et al 1990), and therefore for maintaining the normal tubular shape.…”

Section: Discussionmentioning

confidence: 87%

Effects of high doses of testosterone propionate and testosterone enanthate on rat seminiferous tubules — a stereological and cytological study

1993

View full text Add to dashboard Cite

The effects of exogenous testosterone on various testicular variables has become of increasing significance because of its potential use in male contraception. For this reason, high doses of two testosterone esters [testosterone propionate (TP) and testosterone enanthate (TE)] were used in a study of their influence on the morphology, length and curvature of the seminiferous tubules of the rat testis, and on cytological smears of the seminiferous tubules epithelium. TP was given for 14 days (3 mg/100 g body weight, i.m.) to assess the acute effects of testosterone on the seminiferous tubules. TE was administered for 60 days (in the same manner as TP) to study possible chronic effects on the rat testis. After TP and TE treatment the seminiferous tubule epithelium showed disorganization and desquamation of spermatogenic cells. In the TP-treated testes the tubules lined with Sertoli cells only were observed. The values for the length and curvature of seminiferous tubules of the TP- and TE-treated rats were significantly reduced (p < 0.001). All these changes were observed earlier in the TP-treated than in the TE-treated animals. In cytological smears of the testis of the TP- and TE-treated rats an increase of vacuoles and residual bodies in Sertoli cell cytoplasm was noted. In addition, a reduction of spermatogenic cells, particularly sperms, was manifest in the smears after treatment. Large groups of Sertoli cells were seen in the smears from these testes.

show abstract

Section: Discussionmentioning

confidence: 87%

Effects of high doses of testosterone propionate and testosterone enanthate on rat seminiferous tubules — a stereological and cytological study

1993

View full text Add to dashboard Cite

show abstract

“…Unfortunately, any significant differences have not been found between FFA levels in the various rat groups (Table 1). A slightly suppressed level of TT in the group of trained rats treated with a lower TE dose (8 mg kg BM -1 ) as compared to trained, steroid-untreated controls might result from exogenous administration of TE, which is known to induce suppression of endogenous testosterone [26,27]. Notably, for this group, a disappearance of a shoulder at about 75°C on the DSC curve was observed.…”

Section: Resultsmentioning

confidence: 86%

Calorimetric monitoring of the effect of endurance training and testosterone treatment on rat serum denaturation transition

Michnik

Drzazga

Sadowska-Krępa

et al. 2014

J Therm Anal Calorim

View full text Add to dashboard Cite

Differential scanning calorimetry (DSC) was applied to evaluate whether endurance training and/or testosterone treatment affect thermal behavior of rat serum. Thirty-six adolescent male Wistar rats were divided into six groups: three untrained and three trained groups, receiving weekly 0, 8, or 80 mg kg BM -1 of testosterone enanthate (TE) each. Total testosterone was significantly higher in both groups treated with the higher TE dose. The rats' body mass and the levels of serum glucose, uric acid, and free fatty acids were additionally determined. The effect of TE treatment was clearly visible in DSC curves for sedentary rats and much less for trained rats. The differences between averaged endothermic denaturation transitions of serum from sedentary and physically active untreated groups were within an experimental error. A statistically significant increase of the width of peak at its half height and the ratio of excess heat capacity at 75°C and in the temperature of peak maximum (C p75 /C pmax ) were observed due to TE treatment. The same two parameters were significantly lower for physically active rats. Significantly lower values of the enthalpy of serum denaturation (DH) and the first moment of the transition with respect to the temperature axis (M 1 ) were observed for endurance-trained than for sedentary rats.

show abstract

“…In fact, the observed PK profile after a TNG dose is a sum of all sources of testosterone [20, 21]; exogenous and endogenous sources were not independently quantifiable in this study. When exogenous testosterone was administered, there was a suppression of LH and testosterone production.…”

Section: Discussionmentioning

confidence: 91%

Efficacy of Nasal Testosterone Gel (Natesto®) Stratified by Baseline Endogenous Testosterone Levels

Gronski¹,

Grober

Gottesman

et al. 2019

Journal of the Endocrine Society

View full text Add to dashboard Cite

Objective Pharmacokinetic and efficacy data from a phase 3 testosterone nasal gel (TNG) study were stratified by baseline endogenous testosterone level in patients with testosterone deficiency. Total testosterone (TT), LH, and FSH levels, as well as erectile function, mood, and lean body mass for each group were compared. In a subset of patients with very low baseline endogenous testosterone levels (<100 ng/dL), we investigated whether TNG is a suitable treatment option. Materials and Methods Patients with testosterone deficiency (serum TT <300 ng/dL) were treated with TNG for 3 months, followed by safety extension periods of 90 and/or 180 days. Pharmacokinetic parameters were calculated from serum hormone levels on days 30 and 90, along with efficacy measurements, which were analyzed by comparison with baseline values. Baseline and/or predose TT values were used for patient stratification. Results Prestudy and predose endogenous testosterone concentrations correlated. The maximal concentration of TT was nearly identical across all cohorts at days 30 and 90, whereas the average concentration over 24 hours had a slight positive dependence relative to predose levels. LH levels remained in the normal range but were decreased more in patients with higher starting baseline levels. These findings indicate that TNG works with an active hypothalamic-pituitary-gonadal axis that responds to each dose of TNG throughout the treatment period. Patients with the lowest endogenous testosterone levels received maximum exposure impact from each TNG dose. Patients with severe testosterone deficiency had similar efficacy improvements as the remainder of the study population. Conclusion All testosterone-deficient cohorts were successfully treated with TNG.

show abstract

Acute suppression of endogenous teststterone levels by exogenous testosterone in normal men

Cited by 13 publications

References 18 publications

Effects of high doses of testosterone propionate and testosterone enanthate on rat seminiferous tubules — a stereological and cytological study

Effects of high doses of testosterone propionate and testosterone enanthate on rat seminiferous tubules — a stereological and cytological study

Calorimetric monitoring of the effect of endurance training and testosterone treatment on rat serum denaturation transition

Efficacy of Nasal Testosterone Gel (Natesto®) Stratified by Baseline Endogenous Testosterone Levels

Contact Info

Product

Resources

About