摘要:

Growth-stimulating activity of plasma was measured, both as thymidine activity using a lymphocyte bioassay and as sulfation activity using a cartilage bioassay, in 72 constitutionally short children aged 1–6 years and 38 age-matched controls. Plasma transferrin was also measured. No significant differences were found between the two groups. However, short children aged 1–3 years did not have a higher thymidine activity than children aged 4–10 years, whereas in normals the thymidine activity was significantly higher in the first years of life. Thymidine activity was lower in female than in male constitutionally short chi

ISSN:1663-2818    

DOI:10.1159/000179837

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

This study of the effect of serum dialysis on thymidine incorporation into lectin-activated blood lymphocytes cultured in vitro showed that (1) after serum dialysis 3H-thymidine incorporation is very low or absent; (2) the addition of L-glutamine to dialyzed sera leads to recovery of 18% of 3H-thymidine uptake, and (3) addition of L-glutamine reduces the difference in the stimulating effects of acromegalic and hypopituitary sera observed before dialysis in a medium free of L-glutamine. Since the plasma level of glutamine is increased in acromegalics and reduced in hypopituitary patients, it is suggested that this amino acid acts as a growth hormone dependent factor or cofactor in the regulation of cell growth.

ISSN:1663-2818    

DOI:10.1159/000179853

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

We attempted to determine whether the suppression by histamine of spontaneous episodic growth hormone (GH) secretion is mediated by an augmented release of somatostatin (SS). Adult male rats were passively immunized against SS by the injection of a specific goat anti-SS antibody. Plasma GH levels in rats bearing indwelling catheters were measured at 15-min intervals for 4 h. Histamine (0.1 µmol/rat) was administered intracerebroventricularly (i.e. v.) 1 h after the start of the experiment and once an hour for the next 2 h. Anti-SS serum (2 ml) was injected 2 h after the beginning of the experiment to two groups of rats, one given saline i.e.v. and the other histamine i.c.v. Histamine was able to suppress not only spontaneous GH secretion but also the antiserum-stimulated GH release. These data suggest that histamine inhibition of GH is not mediated by SS but probably by a reduction of GH-releasing hormone or some other stimulatory signal

ISSN:1663-2818    

DOI:10.1159/000179854

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

The bone mineral content was evaluated in 30 male subjects aged between 60 and 90 years using the relief of the percent cortical area (PCA) at the level of the second phalanx of the left-hand index finger, by Garn’s method. This was to evaluate the rate of bone loss with increasing age. Testosterone, androstenedione, estrone, 17β-estradiol plasma levels were determined in all subjects by the RIA method. 60% of our patients showed increased bone resorption (PCA < 55%); in these subjects testosterone and androstenedione plasma levels were significantly lower than in subjects not affected by osteoporosis. A positive linear correlation is evident between PCA and testosterone, androstenedione and estrone plasma levels. Thus, like in women, decline of gonadic function determines an increased bone resorption in men t

ISSN:1663-2818    

DOI:10.1159/000179855

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

The effect of long-term hCG administration on sperm output was evaluated in a study in 3 hypogonadal patients with a selective deficiency of gonadotrophins (LH and FSH). The diagnosis of complete hypogonadotropic hypogonadism was based on clinical and hormonal findings as well as testicular histology. Pubertal maturation took place gradually during hCG therapy. 2 out 3 patients, who were azoospermic before treatment, had spermatozoa in their ejaculate after 12 and 24 months of therapy respectively. These effects on spermatogenesis were reversed after hCG withdrawal for 4 months and the patients again became azoospermic. This azoospermia was not reversed by testosterone (T) replacement therapy, or by addition of HMG to T. In vitro, the crude hCG preparation stimulated cAMP accumulation in rat Sertoli cell cultures indicating that this hCG preparation possesses an ‘FSH-like’ action. The present findings indicate that hCG therapy alone can induce and maintain spermatogenesis in some patients with complete hypogonadotropic hypogonad

ISSN:1663-2818    

DOI:10.1159/000179856

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

Basal plasma prolactin concentration is controlled by tonic inhibition. The major prolactin-inhibiting factor (PIF) is believed to be dopamine. Factors other than dopamine have also been suggested as possible physiological PIF. One of the major candidates for the nondopaminergic PIF is considered to be gamma-aminobutyric acid (GABA). We have carefully examined the possible physiological role of GABA by monitoring, at every 2 min, the circulating prolactin concentration after GABA administration, in conscious freely moving rats. GABA (0.1 or 1 g/kg) had no significant direct effect on plasma prolactin in rats in which the dopaminergic receptors were completely blocked by pimozide, nor in hypophysectomized rats in which a pituitary had been grafted under the kidney capsule and was therefore removed from any hypothalamic influence. The effects of bicuculline, a GABA-receptor-blocking agent, was examined in order to find out whether a tonic inhibition is exerted by GABA after elimination of tonic dopaminergic inhibition on prolactin secretion. The pimozide-treated rat in which the dopaminergic tone is completely eliminated did not show any prominent elevation of plasma prolactin concentration after bicuculline (300 µg/kg) administration. However, GABA did have an inhibitory effect in a primary pituitary cell monolayer culture system. Therefore, we conclude that GABA does not play a significant role as a physiological PIF and that the inhibitory effect of GABA in vitro is of a pharmacological nature

ISSN:1663-2818    

DOI:10.1159/000179857

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

In previous study the major psychoactive ingredient of marihuana (Δ1-THC) has been shown to inhibit ovarian prostaglandin synthesis when administered to normally cycling rats in the early afternoon of proestrus. These results suggested a direct suppressive effect of the drug on the ovary. The purpose of this study was to evaluate the effect of Δ1-THC on steroidogenesis in granulosa cells (GC) in vitro. Incubation of GC with Δ1-THC (10–50 µM) effectively inhibited LH-stimulatable progestin production. This suppressive effect was not abolished by washing the cells after 24 h of culture in the presence of Δ1-THC, indicating the irreversible nature of the blocking effect of Δ1-THC. By contrast, estradiol production following incubation of GC with testosterone (1 µg/ml) was not inhibited by similar concentrations of Δ1-THC, thus suggesting that △1-THC does not inhibit aromatase activity in GC. In addition, Δ1-THC was shown to inhibit cAMP production as well as 125I-hCG binding capacity to GC. Administration of 8-Br-cAMP did not abolish the Δ1-THC-induced block, suggesting that the drug probably acts distal to the cAMP s

ISSN:1663-2818    

DOI:10.1159/000179858

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

We have compared the response of mammary explants obtained from GR mice with those derived from GR/Mtv-2- congenic mice towards hormones and tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA). In explants of the mammary glands of virgin GR mice, insulin, prolactin, progesterone and TPA stimulated the rate of (3H)-thymidine incorporation into DNA. A significantly lower response towards prolactin and TPA was observed in mammary explants derived from GR/Mtv-2- mice. The differential sensitivity of mammary tissues from GR and GR/Mtv-2-mouse strains to the actions of prolactin and tumor promoter is directly correlated to their different incidences of spontaneous tumor formation; it is not known if there is a causal relationship.

ISSN:1663-2818    

DOI:10.1159/000179868

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

The pharmacokinetics of ethynyl estradiolsulfonate labelled with 3H in the steroid nucleus and with 14C in the isopropylsulfonic acid side chain was investigated in male minipigs. The plasma level after intravenous administration was interpreted according to a three-compartment model. After oral administration the first two phases were overlapped by the absoφtion period. The renal and fecal excretion of the two labellings were investigated. In urine the majority of the 3H-labelled steroid was excreted in the unconjugated and in the glucuronide fractions. More than 70% of 14C in urine was unextractable

ISSN:1663-2818    

DOI:10.1159/000179840

出版商:S. Karger AG    

年代:1984

数据来源: Karger