Endokrinologie最新文献

Wistar female rats were injected with testosterone (T) or 5 alpha-dihydrotestosterone (5 alpha-DHT) from the day of birth (= day 1) to day 5. Neonatal treatment with 1 mg of T resulted in anovulatory persistent estrous syndrome in 100% of the animals. In the females treated with 1 mg of 5 alpha-DHT, 88.2% of the treated rats were sterile at 120 days of age. Treatment with 0.5 mg 5 alpha-DHT was also effective in inducing anovulatory sterility, the incidence of sterility being 71.4%. In the females injected with 0.1 mg 5 alpha-DHT, 42.9% of the animals were anovulatory at 120 days of age. These results suggest that non-aromatizable androgen, 5 alpha-DHT, can permanently suppress the development of female type of neuroendocrine regulation.

Two batches of synthetic human calcitonin batch A = delivered until 1976, and batch B = distributed since 1977 from Ciba-Geigy, have been tested and compared biologically and radioimmunologically. In the biossay B is almost twice as active as A when compared ampoule content and exerts a biological activity of 188 IU per mg pure hCT. In the radioimmunoassay there is no difference from each other in radioiodination and purification, but using them as standard and again comparing them on declared ampoule content, B contains twice as much immunological activity as A. For those, who are using hCT for analytic or biological purposes it is of importance to consider the increased hormone content of batch B with a twofold biological and immunological activity, in comparison to the preparations delivered before 1977.

Adult, sexually experienced male rats were castrated and two weeks later implanted with 5 or 10 mm long testosterone-filled silastic capsules (inner diameter 1.4 mm). From the seventh up to the fourteenth week following implantation the majority of males was found to be in the state at which they initiated copulatory behaviour with proceptive (darting) females but not with passively receptive (lordotic) females. Being in this state, their copulatory performance was comparable with precastration level except the decreased frequency of intromission befor the first ejaculation. As to the precopulatory behaviour, the males displayed it even towards females which did not stimulate copulatory behaviour in these males. In all the applied measures no difference between the 5 and 10 mm capsules was revealed. The used implants were found behaviourally effective about fourteen or nineteen weeks throughout following implantation or reimplantation, respectively.

Urinary E1, E2, E3 and pregnandiol were determined in 60 premenopausal and 12 postmenopausal breast cancer patients before and after mastectomy, as well as in 30 normal females. Data obtained showed great individual variation. The general findings were low oestrogens in young patients, normal in old premenopausal patients and high in postmenopausal patients. The ratio E3/E1 + E2 showed comparatively high values in premenopausal patients. Pregnandiol excretion was low in almost all premenopausal patients with the exception of few cases in the different age groups. The changes in the hormonal pattern in premenopausal breast cancer patients, before and after mastectomy, and of postmenopausal patients were discussed in view of the current literature.

The effect of abortion on serum concentration of thyroid hormones was studied in 11 normal women. After abortion, serum free and total T3 fall significantly, while free and total reverse T3, T4, TSH and TBG in serum show no significant variation. These data suggest that surgical stress in normal subjects may only influence 5'-deiodinase activity, and that the peripheral conversion of T4 to active T3 and inactive rT3 are controlled by different mechanisms.

Thio-protein disulphide oxidoreductase (TPO) was demonstrated in rat and fish brain by use of the indirect peroxidase-antiperoxidase technique. TPO immunoreactivity was found to be widely distributed throughout rat CNS. Whereas most nerve cells possessed only weak immunoreactivity to the enzyme, the neurosecretory cells of Nuc. supraopticus and Nuc. paraventricularis were heavily laden with immune products. In fishes (rudd) the neurosecret-producing neurons of the Nuc. preopticus were the only locus being positive for TPO. From our findings we conclude that thiol-protein disulphide oxidoreductase might be involved into the process of neurophysin synthesis.

The aim of the present study was to find a relation between the Substance P (SP) content in the median eminence and the pituitary gland in rats and hypothalamic regulaton of the oestrus cycle. SP content was measured by radioimmunoassay in female rat pituitary and median eminence during oestrus, dioestrus and after anterior hypothalamic deafferentation. SP content in rat's pituitary did not vary significantly among individual groups of animals. The greatest average SP content in rat's median eminence was found in dioestrus. Both during cyclic and constant oestrus resulting from anterior hypothalamic deafferentation SP content in median eminence was lower than in dioestrus. This fact indicates the possibility of SP involvement in the control of cyclic LH-RH release from hypothalamus.

Newborn Sprague-Dawley rats were ovariectomized within 24 h of birth and control animals were sham-operated. Immediately, one-half of the rats in each group received a single injection of 500 micrograms testosterone propionate. The other half acted as a vehicle control. Normal male and female rats were also included for comparison. The secretion rate of sebum was measured at the age of 80 days from the amount of skin-surface lipids that could be extracted with acetone and which had been produced during 2 days. Male rats secreted more sebum than female rats. In female rats, irrespective the presence or absence of ovaries, when treated with a single injection of testosterone propionate at birth, although secreted significantly more sebum than vehicle control groups, the increase was still far below the level normally found in the male. On the other hand, implantation of testosterone pellet at the age of 4 weeks in neonatally ovariectomized-androgenized female rats greatly increased sebum secretion to an extent far exceeding that of the normal male rats. It is concluded that testosterone can directly increase sebum secretion in the female rats irrespective the presence or absence of ovaries when given at birth and reinforcement at about puberty produces a full effect of secretion.

Neonatal exposure of rats to oxytocin + TSH damaged the receptor in the same manner as neonatal treatment with high dose of TSH alone. Exposure to oxytocin af adult rats given oxytocin + TSH when newborn depressed hormone reception of a similar degree to TSH, suggesting the possibility of an association between the two receptor sites.