THE EFFECT OF GONADOTROPHIN RELEASING HORMONE ON PITUITARY-GONADAL FUNCTION IN KLINEFELTER'S SYNDROME

1976 ◽  
Vol 83 (4) ◽  
pp. 829-838 ◽  
Author(s):  
A. G. H. Smals ◽  
P. W. C. Kloppenborg ◽  
R. M. Lequin ◽  
Th. J. Benraad
Keyword(s):  
Leydig Cells ◽  
Bolus Injection ◽  
Plasma Testosterone ◽  
Klinefelter’S Syndrome ◽  
Klinefelter's Syndrome ◽  
Releasing Hormone ◽  
Basal Plasma ◽  
Gonadotrophin Releasing Hormone ◽  
The Mean ◽  
Lh Rh

ABSTRACT The mean basal plasma LH and FSH levels in 8 patients with Klinefelter's syndrome were respectively 5 and 15-fold higher than in 8 eugonadal males, whereas plasma testosterone concentration were half the normal value After an intravenous bolus injection of gonadotrophin releasing hormone (100 μg of LH-RH) the gonadotrophin increase in the Klinefelter patients was more marked than in the control subjects, but in both groups the plasma testosterone levels remained essentially unchanged. In contrast to the bolus injection, an 8 h infusion of LH-RH after the bolus elicited a significant plasma testosterone increase in both the eugonadal males (59%) and the Klinefelter patients (51%). These findings indicate that despite an impressive endogenous hypergonadotrophism, Leydig cells in Klinefelter's syndrome can still respond to a sustained further increase of these endogenous gonadotrophins and thus still have functional reserve.

PLASMA TESTOSTERONE IN KLINEFELTER'S SYNDROME: DIURNAL VARIATION AND RESPONSE TO ACTH AND DEXAMETHASONE

1975 ◽  
Vol 78 (3) ◽  
pp. 604-612 ◽  
Author(s):  
A. G. H. Smals ◽  
P. W. C. Kloppenborg ◽  
T. J. Benraad
Keyword(s):  
Plasma Testosterone ◽  
Klinefelter’S Syndrome ◽  
Klinefelter's Syndrome ◽  
Normal Range ◽  
Short Term ◽  
Plasma Testosterone Level ◽  
Testosterone Levels ◽  
Basal Plasma ◽  
Order Of Magnitude ◽  
The Mean

ABSTRACT The mean basal plasma testosterone level in 28 patients with chromatin positive Klinefelter's syndrome was significantly lower than in 58 healthy male controls. In 12 of the patients the hormone levels were in the normal range. In both the eugonadal males and the Klinefelter patients the plasma testosterone levels spontaneously decreased throughout the day, the relative decrease in both groups being of the same order of magnitude. Short term ACTH infusion and the administration of dexamethasone did not significantly influence the plasma testosterone concentration in the Klinefelter patients. These findings do not support the view that the adrenal cortex plays a major role in contributing to the circulating plasma testosterone levels in this syndrome.

THE EFFECT OF SHORT AND LONG TERM HUMAN CHORIONIC GONADOTROPHIN (HCG) ADMINISTRATION ON PLASMA TESTOSTERONE LEVELS IN KLINEFELTER'S SYNDROME

1974 ◽  
Vol 77 (4) ◽  
pp. 753-764 ◽  
Author(s):  
A. G. H. Smals ◽  
P. W. C. Kloppenborg ◽  
Th. J. Benraad
Keyword(s):  
Plasma Testosterone ◽  
Klinefelter’S Syndrome ◽  
Klinefelter's Syndrome ◽  
Absolute Increase ◽  
Testosterone Levels ◽  
Basal Plasma ◽  
Patient Groups ◽  
Pre Treatment ◽  
Secondary Hypogonadism

ABSTRACT The effect of acute (1500 IU/day for 3 days) and chronic HCG administration (1500 IU, 3 times weekly) on plasma testosterone levels in patients with Klinefelter's syndrome was compared with the response observed in patients with hypogonadotrophic eunuchoidism and in eugonadal male controls. Basal plasma testosterone levels in the Klinefelter patients were significantly lower than in the control subjects and significantly higher than in the patients with secondary hypogonadism. In all but one Klinefelter patient the plasma LH levels were markedly elevated even in the presence of normal testosterone levels. No significant correlation could be demonstrated between the plasma testosterone concentrations and the LH levels in the Klinefelter patients. Short term HCG administration resulted in a significant increase in the plasma testosterone levels in each of the 3 groups studied, independent of the basal value. The absolute increase in the Klinefelter patients was quantitatively comparable to that in the patients with secondary hypogonadism, but significantly lower than in the eugonadal controls. During long term HCG treatment the plasma testosterone levels definitely increased in both patient groups, but remarkably in the Klinefelter patients testosterone levels tended to decrease on continuing treatment, though in most patients testosterone levels remained higher than the pre-treatment values. The data on the effect of acute and chronic HCG administration on plasma testosterone levels in this study illustrate again that Leydig cells in Klinefelter's syndrome still retain a functional reserve, though less than in eugonadal males.

BODY PROPORTIONS AND ANDROGENICITY IN RELATION TO PLASMA TESTOSTERONE LEVELS IN KLINEFELTER'S SYNDROME

1974 ◽  
Vol 77 (2) ◽  
pp. 387-400 ◽  
Author(s):  
A. G. H. Smals ◽  
P. W. C. Kloppenborg ◽  
T. J. Benraad
Keyword(s):  
Upper Body ◽  
Clinical State ◽  
Plasma Testosterone ◽  
Klinefelter’S Syndrome ◽  
Body Segment ◽  
Klinefelter's Syndrome ◽  
Testosterone Levels ◽  
Arm Span ◽  
Basal Plasma ◽  
Low Testosterone

ABSTRACT Basal plasma testosterone levels (mean ± sd 290 ± 141 ng/100 ml) (range 72–684 ng/100 ml) in 25 chromatin positive patients with Klinefelter's syndrome (23 XXY, 1 XXYY, 1 XY/XXY) were significantly lower than in 25 age matched controls (mean ± sd 603 ± 169 ng/100 ml). In 11 out of the 25 Klinefelter patients however, plasma testosterone levels were in the normal range and these patients differed significantly from the patients with low testosterone levels with respect to the clinical state of androgenicity. In the group of Klinefelter patients, but not in the controls, a significant negative correlationship was found between plasma testosterone levels and each of the variables: body weight, arm span, length of the lower body segment and the ratio's lower/upper and span/upper body segment.

CORRELATION OF PITUITARY AND TESTICULAR RESPONSES TO STIMULATION TESTS IN CRYPTORCHID CHILDREN

1977 ◽  
Vol 86 (3) ◽  
pp. 641-650 ◽  
Author(s):  
Dominique Gendrel ◽  
Marc Roger ◽  
Jean-Louis Chaussain ◽  
Pierre Canlorbe ◽  
Jean-Claude Job
Keyword(s):  
Leydig Cells ◽  
Significant Positive Correlation ◽  
Plasma Testosterone ◽  
Early Puberty ◽  
Testosterone Levels ◽  
Short Course ◽  
Basal Plasma ◽  
Stimulation Tests ◽  
Lh Rh ◽  
Lh Secretion

ABSTRACT LH-RH test and HCG stimulation test were performed in 154 cryptorchid boys aged 1 month to 15 years (64 unilateral and 90 bilateral). Basal plasma LH levels and LH response to LH-RH were significantly lower from infancy to early puberty in cryptorchids compared with controls. Basal FSH levels and FSH response to LH-RH were normal. The post-HCG rise of plasma testosterone was reduced until mid-puberty. A significant positive correlation was found between post-HCG testosterone levels and pre- and post-LH-RH levels of LH. This correlation suggests that testicular maldescent and the decreased ability of Leydig cells to respond to a short course of HCG may result from an early defect or a delay of pituitary LH secretion.

Effect of decapitation and chronic in-vivo treatment with a gonadotrophin-releasing hormone agonist on testicular steroidogenesis in the rat fetus

1992 ◽  
Vol 133 (2) ◽  
pp. 245-251 ◽  
Author(s):  
R. Habert
Keyword(s):  
Gnrh Agonist ◽  
Leydig Cells ◽  
Maternal Plasma ◽  
Plasma Testosterone ◽  
Fetal Life ◽  
Rat Fetus ◽  
Control Female ◽  
Releasing Hormone ◽  
Gonadotrophin Releasing Hormone

ABSTRACT To study the effect of in-vivo gonadotrophin-releasing hormone (GnRH) treatment on testicular testosterone production during late fetal life in the rat, 18·5-, or 20·5-day-old fetuses were decapitated and injected with either long-acting microcapsules containing the GnRH agonist d-Trp-6-GnRH or vehicle only. Two days later, fetal and maternal plasma was collected and fetal testes were removed and incubated for 6 h in medium with either 100 ng LH/ml or without LH. The GnRH agonist concentrations in the plasma of GnRH-treated decapitated male fetuses were comparable in the two age-related groups (5 nmol/l). After treatment of the fetus with d-Trp-6-GnRH, the agonist was recovered in maternal plasma, showing that this peptide can cross the fetal–maternal barrier. In 22·5-day-old decapitated vehicle-treated male fetuses, the plasma testosterone level dropped to that observed in control female fetuses, and treatment of decapitated male fetuses with the GnRH agonist did not further reduce it. At both days 20·5 and 22·5, basal in-vitro testosterone secretion by testes from decapitated vehicle-treated fetuses was lower than secretion by testes from intact control fetuses from the same litter, but LH-stimulated secretion was similar in both groups. Both basal and LH-stimulated secretion by testes from GnRH-treated decapitated fetuses was lower than secretion by testes from vehicle-treated decapitated fetuses and larger reductions were measured on day 22·5 than on day 20·5 (−48 vs −18% for basal secretion, and −76 vs −40% for LH-stimulated secretion). These results suggest that, in contrast to immature Leydig cells, fetal Leydig cells are not desensitized to gonadotrophic stimulation after hypophysial deprivation, and that, in the rat, a negative testicular response to a putative intratesticular GnRH or to some other factor using the same intracellular pathway is established during late fetal life. Journal of Endocrinology (1992) 133, 245–251

PITUITARY LH AND FSH AND TESTOSTERONE SECRETION IN INFANTS WITH UNDESCENDED TESTES

1977 ◽  
Vol 85 (3) ◽  
pp. 644-649 ◽  
Author(s):  
Jean-Claude Job ◽  
Dominique Gendrel ◽  
Anne Safar ◽  
Marc Roger ◽  
Jean-Louis Chaussain
Keyword(s):  
Leydig Cell ◽  
Plasma Levels ◽  
Leydig Cells ◽  
Plasma Testosterone ◽  
Normal Range ◽  
Undescended Testes ◽  
Cell Axis ◽  
Testosterone Secretion ◽  
Basal Plasma ◽  
Lh Rh

ABSTRACT Twelve male infants with undescended testes (5 bilaterally, 7 unilaterally) were studied between the ages of 1 week and 11 months. As in older pre-pubertal cryptorchid boys, a significant decrease of the LH response to LH-RH test was found, while basal plasma levels of gonadotrophins and FSH response to LH-RH were normal. Plasma testosterone levels were in the normal range, and Leydig cells responded to stimulation by HCG, the degree of this response being significantly and positively correlated to the LH peak elicited by LH-RH. It may be concluded that some early defect of the pituitary-Leydig cell axis is associated with undescended testes.

Indirect evidence of chronic Leydig cell desensitization in Klinefelter's syndrome

1981 ◽  
Vol 96 (4) ◽  
pp. 552-556 ◽  
Author(s):  
Anthony G. Smals ◽  
Gerlach F. Pieters ◽  
Peter W. Kloppenborg
Keyword(s):  
Leydig Cells ◽  
Response Pattern ◽  
Indirect Evidence ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Klinefelter’S Syndrome ◽  
Klinefelter's Syndrome ◽  
Basal Plasma ◽  
Normal Men ◽  
T Values

Abstract. The basal plasma 17α-hydroxyprogesterone (17-OHP) and testosterone (T) levels were proportionally decreased in 10 hypergonadotropic patients with Klinefelter's syndrome. The ratio 17-OHP to T was however about twice as high as in 10 eugonadal male controls, suggesting the presence of a block in the conversion of 17-hydroxylated steroids to androgens in the Klinefelter patients under basal circumstances. Administration of human chorionic gonadotrophin (hCG, 1500 IU im daily for 3 days) to the Klinefelter patients disclosed a response pattern quite different from that observed in controls. In the control subjects 17-OHP and the ratio 17-OHP/T sharply rose to maximum values at 24 h after the first injection. Thereafter both progressively fell to lowest values at 72 h, when T levels reached their maximum. In the Klinefelter patients the T response to hCG administration was greatly diminished but the 17-OHP response was similar to that in the controls. Maximum 17-OHP and 17-OHP/T values however were not achieved until 72 h after the first injection when T levels also reached their maximum. Unlike in the controls in the Klinefelter patients maximum 17-OHP and T increments and the 17-OHP and T levels 48 and 72 h after the injection were positively correlated. Together the findings of a decreased T synthesis and reserve in the presence of relative 17-OHP accumulation, further increasing after acute hCG administration in a pattern quite different from that in normal men, suggest that in Klinefelter's syndrome the Leydig cells may be chronically desensitized by the persistent endogenous hypergonadotropism.

HYDROXYSTEROID DEHYDROGENASES IN NORMAL AND ABNORMAL HUMAN TESTES

1966 ◽  
Vol 35 (3) ◽  
pp. 239-NP ◽  
Author(s):  
A. H. BAILLIE ◽  
W. S. MACK
Keyword(s):  
Similar Pattern ◽  
Leydig Cells ◽  
Seminiferous Tubules ◽  
Klinefelter’S Syndrome ◽  
Klinefelter's Syndrome ◽  
Colour Reaction ◽  
Adult Human ◽  
Hydroxysteroid Dehydrogenases

SUMMARY 3α-, 3β-, 11β-, 16β-, 17β- and 20β-hydroxysteroid dehydrogenases have been localized histochemically in the Leydig cells of prepubertal and adult human testes; 3α-, 16β- and 17β-hydroxysteroid dehydrogenases were present in the seminiferous tubules also. A similar pattern was found in cryptorchid testes. In addition 3β-sulphoxy steroids, including DHA sulphate, gave a good colour reaction in human Leydig cells. Testes from oestrogen-treated subjects had no histochemically demonstrable hydroxysteroid dehydrogenases and this applied also to infarcted testes. Testes from a case of Klinefelter's syndrome were found to lack 17β- and 20β-hydroxysteroid dehydrogenases in the Leydig cells. The biochemical significance of these results is discussed.

THE EFFECT OF CYPROTERONE ACETATE ON THE PLASMA GONADOTROPHIN RESPONSE TO GONADOTROPHIN RELEASING HORMONE

1976 ◽  
Vol 81 (3) ◽  
pp. 680-684 ◽  
Author(s):  
Richard A. Donald ◽  
Eric A. Espiner ◽  
R. John Cowles ◽  
Joy E. Fazackerley
Keyword(s):  
Testosterone Level ◽  
Cyproterone Acetate ◽  
Luteinising Hormone ◽  
Follicle Stimulating Hormone ◽  
Plasma Testosterone ◽  
Plasma Testosterone Level ◽  
Releasing Hormone ◽  
Lh Release ◽  
Gonadotrophin Releasing Hormone ◽  
Male Patients

ABSTRACT Cyproterone acetate (100–150 mg daily) was administered to 8 male patients with excessive libido. Within 3 months a significant fall (P < 0.02) in plasma testosterone was demonstrated. The plasma luteinising hormone (LH) and follicle stimulating hormone (FSH) responses to gonadotrophin releasing hormone (LH/FSH-RH) were also significantly impaired (P < 0.05). A direct correlation between the resting plasma testosterone level and the LH response to LH/FSH-RH was demonstrated (r = 0.743). It is concluded that the fall in plasma testosterone levels in patients receiving cyproterone acetate may be attributed to suppression of LH release, rather than an antiandrogen effect on the testis or hypothalamus.

Sign in / Sign up

Export Citation Format

Share Document