Testicular oestradiol-17β

Oestrogenic hormones were originally isolated from ovarian follicles and from placental tissue and were believed to occur only in female animals. Laqueur et al. (1927} observed, however, that extracts from human male urine caused vaginal cornification in spayed mice. This discovery of oestrogenic activity in urine from men was so unexpected, that the authors thought it necessary to state that there could be no doubt about the manliness of the subjects studied. One of the oestrogenic substances in human male urine was subsequently identified as oestrone (Dingemanse et al., 1938), while later on oestradiol and oestriol were also found to be present in urine from men (see: Diczfalusy & Lauritzen, 1961). Since then, the occurrence of oestrogens in the urine of male animals from several species has been described (see: Velle, 1966). However, information on the precise origin of these oestrogenic hormones and on the regulation of the production of oestrogens in the male animal is still limited. Therefore, it was decided to investigate these points with special reference to the testis as a possible source of oestradiol

Serum inhibin B as a marker of spermatogenesis

Inhibin B is produced by Sertoli cells, provides negative feedback on FSH secretion, and may prove to be an important marker for the functioning of seminiferous tubules. The purpose of the present study was to examine the relationship between the spermatogenic function of the testis of subfertile men and the plasma concentrations of inhibin B and FSH. These parameters were estimated in a group of 218 subfertile men. Serum inhibin B levels were closely correlated with the serum FSH levels (r = -0.78, P < 0.001), confirming the role of inhibin B as feedback signal for FSH production. The spermatogenic function of the testis was evaluated by determining testicular volume and total sperm count. Inhibin B levels were significantly correlated with the total sperm count and testicular volume (r = 0.54 and r = 0.63, respectively; P < 0.001). Testicular biopsies were obtained in 22 of these men. Inhibin B was significantly correlated with the biopsy score (r = 0.76, P < 0.001). Receiver operating characteristic analysis revealed a diagnostic accuracy of 95% for differentiating competent from impaired spermatogenesis for inhibin B, whereas for FSH, a value of 80% was found. We conclude that inhibin B is the best available endocrine marker of spermatogenesis in subfertile men

Inhibin in immature rat Sertoli cell conditioned medium: a 32 kDa αβ-B dimer

Abstract Conditioned medium of cultured Sertoli cells from 21-day-old rats was used as starting material for the isolation of inhibin. Inhibin activity was monitored by the dose dependent suppression of the folliclestimulating hormone release of cultured rat pituitary cells. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis of the highly purified inhibin preparation revealed a 32 kDa protein after silver staining, which could be separated in subunits of 18 kDa and 12 kDa after reduction. Western blot analysis with an antibody recognizing the 22 N-terminal amino acids of the α-subunit of 32 kDa bovine inhibin confirmed the presence of a 32 kDa inhibin molecule under non-reducing conditions, whereas an 18 kDa a-subunit was found after reduction. An antibody recognizing the β-A subunit of inhibin did not yield a signal after Western blotting. N-terminal amino acid sequence analysis of two highly purified preparations of inhibin obtained using different methods yielded the sequence predicted for a 32 kDa αβ-B dimer on basis of cDNA nucleotide sequence. This result is in agreement with the large excess of β-B over β-A mRNA in the rat testis

Serum dehydroepiandrosterone sulfate levels and pubarche in short children born small for gestational age before and during growth hormone treatment

It has been suggested that the programming of the endocrine axes occurs during critical phases of fetal development and will be affected by intrauterine growth retardation. As a result, children born small for gestational age (SGA) might have several hormonal disturbances. In later life, one of the questions that might arise is: Do short children born SGA have higher serum dehydroepiandrosterone sulfate (DHEAS) levels than their peers? Therefore, we compared serum DHEAS levels of 181 short prepubertal children aged 3-9 yr born SGA [birth length (SD score) below -2 for gestational age] with a control group of 170 prepubertal age-matched, normal-statured children born appropriate for gestational age (birth length between -2 and +2 SD score). Because relatively high serum DHEAS levels at a young age might result in a premature pubarche, we investigated the incidence of premature pubarche. We also investigated the association between serum DHEAS levels and bone maturation. In addition, we analyzed whether 1 yr of GH treatment with 1 and 2 mg/m(2).d ( approximately 0.035 and 0.070 mg/kg.d, respectively) had an effect on serum DHEAS levels of prepubertal short SGA children. Serum DHEAS levels of the SGA group were comparable with those of age-matched appropriate for gestational age controls. The incidence of premature pubarche was comparable with that of the normal population. There was a weak negative correlation between serum DHEAS levels and bone maturation after the age of 7 yr. After 1 yr of GH treatment, the increase of serum DHEAS levels was the same for both GH dosage groups and the untreated group. In conclusion, this study shows that small size at birth, which might be a feature of fetal growth restriction, has no effect on serum DHEAS levels before the age of 9 yr. The incidence of premature pubarche is comparable with the normal population. Finally, 1 yr of GH treatment has no effect on serum DHEAS levels

Plasma testosterone in fetal rats and their mothers on day 19 of gestation

Plasma testosterone levels were higher in pooled samples from male fetuses than from female fetuses on day 19 of pregnancy. Plasma testosterone from female fetuses with males located caudally in the uterus was higher than from females that lacked such males. Testosterone level of both male and female fetuses was correlated with maternal testosterone. No correlation was found between maternal testosterone and number of males in the litter, male-to-female ratio, or litter size. These results corroborate earlier findings of a sex difference in plasma testosterone levels on fetal day 19 in rats, and provide support for the hypothesis that female rats receive androgens from males located caudally in the uterus. No evidence was found that testosterone of pregnant females is affected by the sex ratio or size of her litter

Effects of Testicular and Ovarian Inhibin‐Like Activity, Using In Vitro and In Vivo Systems

Inhibin‐like activities in charcoal‐treated bovine follicular fluid (FF) and medium from cultured Sertoli cells (SCCM) were assayed in an in vitro bioassay system, using cultured pituitary cells. Addition of both fluids resulted in parallel dose‐dependent decreases of the concentration of follicle‐stimulating hormone (FSH) in the medium, both in the presence or absence of luteinizing hormone‐releasing hormone (LH‐RH). A single injection of FF into immature and adult male and female rats resulted in decreased peripheral levels of FSH, but not of LH, after 4 or 8 h. This decrease was larger and occurred faster in adult female rats than in prepubertal female animals. Injection of FF into adult female rats, immediately after unilateral ovariectomy (ULO) prevented the specific increase of FSH levels, occurring in control animals. This suppression could not be obtained after treatment with steroids. Daily treatment of adult female or immature male rats for periods longer than 5 days did not result in prolonged suppression of circulating FSH concentrations; LH levels were significantly increased. The female animals showed cyclic vaginal smear changes and normal ovulation; in the male rats testis weight and numbers of spermatogenic cells were reduced. It is concluded that testicular and ovarian inhibin‐like activities have similar properties. Injections of FF into male and female rats cause similar effects on FSH and LH. The effect of FF in ULO‐animals suggests that inhibin could play a role in the short‐term regulation of the number of developing follicles in the ovary. Injection of FF into male rats causes a probably transient impairment of spermatogenesis through an initial suppression of FSH. Copyrigh

Decrease of free thyroxine levels after controlled ovarian hyperstimulation

Controlled ovarian hyperstimulation could lead to opposing effects on thyroid function. Therefore, in a prospective study of 65 women undergoing controlled ovarian hyperstimulation, thyroid hormones, T4-binding globulin, TPO antibodies, gonadotropins, estradiol, and PRL were measured before and after controlled ovarian hyperstimulation. After ovarian stimulation (mean +/- SE of mean): free T4 decreased, 14.4 +/- 0.2 vs. 12.9 +/- 0.2 pmol/L (P < 0.0001); thyroid-stimulating hormone increased, 2.3 +/- 0.3 vs. 3.0 +/- 0.4 mU/L (P < 0.0001); T4-binding globulin increased, 25.2 +/- 0.7 vs. 33.9 +/- 0.9 mg/L (P < 0.0001); total T4 increased, 98.1 +/- 2.3 vs. 114.6 +/- 2.5 nmol/L (P < 0.0001); total T3 increased, 2.0 +/- 0.04 vs. 2.3 +/- 0.07 nmol/L (P < 0.0001); TPO antibodies decreased, 370 +/- 233 U/mL vs. 355 +/- 224 U/mL (P < 0.0001); LH decreased, 8.1 +/- 1.1 vs. 0.4 +/-0.1 U/L (P < 0.0001); FSH did not change, 6.5 +/- 0.6 vs. 7.9 +/- 0.9 U/L (P = 0.08); human CG increased, <2 +/- 0.0 vs. 195 +/- 16 U/L (P < 0.0001); estradiol increased, 359.3 +/- 25.9 pmol/L vs. 3491.8 +/-298.3 pmol/L (P < 0.0001); and PRL increased, 0.23 +/- 0.02 vs. 0.95 +/- 0.06 U/L (P < 0.0001). Because low maternal free T4 and elevated maternal thyroid-stimulating hormone levels during early gestation have been reported to be associated with impaired psychomotor development in the offspring, our findings indicate the need for additional studies in the children of women who where exposed to high levels of estrogens around the time of conception