摘要:

Since correct assessment of testicular function and androgenic status in humans requires multiple sampling, a sensitive and accurate radioimmunoassay (RIA) of testosterone (T) was established for male and female saliva samples. This easily collected biological fluid, which contains nonprotein-bound T, may represent an attractive alternative or a complement to total plasma T assays. In saliva samples from 5 normal males, a clear circadian rhythm was observed, and morning concentrations (135 ± 31 pg/ml) were significantly higher (p < 0.02) than evening samples (85 ± 23 pg/ml). In 11 normal females, morning saliva levels were 12.8 ± 1.8 pg/ml. The levels of T in male saliva, in response to both exogenous T administration (100 mg i.m.) and HCG stimulation (2 × 2,000 IU i.m.), accurately reflected the changes observed in plasma T, and the magnitude of increase in T levels was clearly greater in saliva than in plasma samples during the intramuscular administration of the long-acting T preparation. In males, significant correlations were observed between salivary and plasma T concentrations in morning samples (r = 0.61, p < 0.01), following HCG stimulation (r = 0.89, p < 0.05) and during T administration (r = 0.87, p < 0.05). In women, the correlation at 8 a.m. was also significant (r = 0.82, p < 0.

ISSN:1663-2818    

DOI:10.1159/000180291

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The circadian variation of 17-hydroxyprogesterone levels in 3 male obligatory carriers of 21 -hydroxylase deficiency (salt-losing form) was not significantly different from that of normal noncarrier male subjects.

ISSN:1663-2818    

DOI:10.1159/000180292

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

This report describes a 38-year-old patient with prolactinoma, without adrenal or thyroid insufficiency, with syndrome of inappropriate secretion of vasopressin due to downward resetting of the hypothalamic osmoreceptors. Random measurements of plasma and urine osmolality revealed an inappropriately high urine osmolality for a given plasma osmolality. Simultaneous plasma vasopressin levels were within normal limits. Urine dilution after water load was normal. During infusion of hypertonic saline, the osmotic threshold was demonstrated at plasma osmolality of 267 mosmol/kg, which is markedly lower than the normal 287.3 ± 3.3 mosmol/kg. Thirst sensation seemed to be intact. The defect in the osmoreceptor function might have been induced by the tumor mass or by chronic hyperprolactinemia

ISSN:1663-2818    

DOI:10.1159/000180293

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The intravenous administration of 250 µg D-Ala2-MePhe4-Met-enkephalin-O-ol (DAMME) caused a marked increase in circulating growth hormone (GH) and prolactin (PRL), and a fall in cortisol, in 14 normal subjects. Neither the α1-antagonist thymoxamine, nor the α2-antagonist yohimbine, significantly altered the GH and PRL responses to DAMME, suggesting that in man the growth hormone- and prolactin-releasing effects of exogenous opioids are not mediated through adrenoceptor pathways. The fall in cortisol induced by DAMME was not affected by thymoxamine, but was significantly attenuated by yohimbine, indicating that opioids may lower circulating cortisol via an interaction with noradrenergic pathwa

ISSN:1663-2818    

DOI:10.1159/000180294

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

We studied the effect of natural and synthetic androgens on children’s erythropoietic precursor cells in culture. Cultures of normal marrow were carried out according to a miniaturized methylcellulose method in the presence of erythropoietin. We then evaluated the effects of testosterone, nortestosterone, fluoxymesterone and etiocholanolone (10-9–10-6M) on erythroid colony-forming units (CFU-E) and burst-forming units (BFU-E). Androgen-induced growth of erythroid progenitors was quantified by directly scoring colonies and by a biochemical determination of the uroporphyrinogen I synthase activity (UROS). We observed a significant increase (p ≤ 0.05) in the number of CFU-E and BFU-E and in the UROS activity of derived colonies in the presence of androgens (10-8 or 10-7M). This microculture assay could be useful not only to study the effect of androgens on erythroid progenitor cells in culture, but also to predict the best androgenic treatment of anemia in children and a

ISSN:1663-2818    

DOI:10.1159/000180295

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The effects of histamine (HA) and related compounds on thyrotropin-releasing hormone (TRH) and thyrotropin (TSH) secretion in rats were studied. Histidine (1.0 g/kg), HA (5.0 mg/kg) or histamine antagonists mepyramine (MP) (100 mg/kg) or famotidine (FA) (5.0 mg/kg) were injected intraperitoneally, and the rats were decapitated at various intervals after the injection. The hypothalamic immunoreactive TRH (ir-TRH) content increased significantly after histidine or HA injection, decreased significantly after FA injection, but was not changed by MP. The plasma ir-TRH concentration did not change significantly after injection of these drugs. The plasma TSH levels decreased significantly in a dose-related manner after histidine or HA injection and increased significantly in a dose-related manner after FA injection. The plasma thyroid hormone levels showed no changes. In the FA-pretreated group, the inhibitory effect of histidine or HA on TSH levels was prevented, but not in the MP-pretreated group. The plasma ir-TRH and TSH responses to cold were inhibited by histidine or HA and enhanced by FA. The plasma TSH response to TRH was inhibited by histidine or HA and enhanced by FA. The inactivation of TRH immunoreactivitiy by hypothalamus or plasma in vitro after histidine, HA, MP or FA was not different from that of the control. These findings suggest that histamine may act both on the hypothalamus and the pituitary to inhibit TRH and TSH release, and that its effects may be mediated via H2-receptor.

ISSN:1663-2818    

DOI:10.1159/000180296

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The temporal effects of intracerebroventricular (icv) infusion of prolactin (PRL) on endogenous PRL secretion was investigated in intact, freely moving, cycling rats. An icv infusion of 10 ng or 100 ng rat-PRL/min from 13.00 to 17.00 h during the proestrous afternoon did not affect endogenous PRL secretion; infusion from 09.00 to 13.00 h showed a tendency to delay the time of onset of the PRL proestrous afternoon surge. The results do not indicate the involvement of an autoregulatory mechanism in the expression or the termination of the proestrous afternoon surge of PRL secretion.

ISSN:1663-2818    

DOI:10.1159/000180297

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The effect of 5-hydroxytryptamine (5-HT) alteration on brain dopamine (DA), norepinephrine (NE), β-endorphin (βE) and immunoreactive insulin (IRI) was studied in Sprague-Dawley diabetic and control rats. Diabetes was induced using alloxan (45 mg/kg), 15 days prior to sacrificing. Both control and diabetic animals were treated with either p-chlorophenylalanine (PCPA, 300 mg/kg) 3 days prior to sacrificing or fluoxetine (10 mg/kg) twice daily for 3 days. PCPA treatment significantly decreased brain content of 5-HT and 5-hydroxyindole acetic acid (5-HIAA) while it caused significant increase and decrease in brain βE and insulin levels, respectively, in both normal and diabetic rat. Meanwhile, the administration of fluoxetine resulted in significant increase in brain content of 5-HT, DA, NE and insulin but significant decline of βE in diabetic and saline control rats. The results of this experiment indicate that 5-HT may be regulating both βE and insulin regardless of the availability of pancreatic ins

ISSN:1663-2818    

DOI:10.1159/000180298

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

In the present study we investigated the effects of castration on androstenedione (A), testosterone (T) and dihydrotestosterone (DHT) plasma levels in adult male rats 5 and 47 days after castration. In another group of 60-day-old castrated rats, the three steroids have been evaluated during testosterone propionate administration. Our data show that 5 days after orchiectomy all three steroids were significantly decreased (p < 0.001) with respect to control values. 47 days after orchiectomy, T and DHT were also significantly decreased with respect to the control group. In both groups of orchiectomized rats the A/T ratio increased significantly with respect to controls. On the contrary, the T/DHT ratio sharply decreased. This suggests that DHT, in orchiectomized rats, could derive from precursors other than T A negative correlation between A and the T/DHT ratio was observed 47 days after castration in adult animals and emphasized upon testosterone propionate administration. In the latter group, T was significantly lower while A is significantly augmented with respect to control values. Finally, the above-mentioned negative correlation indicates a possible prevalent role of A in contributing to the circulating levels of DHT in adult orchiectomized rats.

ISSN:1663-2818    

DOI:10.1159/000180299

出版商:S. Karger AG    

年代:1986

数据来源: Karger

ISSN:1663-2818    

DOI:10.1159/000180300

出版商:S. Karger AG    

年代:1986

数据来源: Karger