性激素与原发性高血压

目的探讨性激素与高血压发病的关系。方法采用放射性免疫分析法检测５６例男性ＥＨ患者和２１例健康男性对照，４１例绝经后女性ＥＨ患者和２１例健康绝经后女性对照血清雌二醇（Ｅ２），孕酮（Ｐ）和睾酮（Ｔ）水平，进行对比研究。结果（１）男性ＥＨ组血清Ｔ水平明显低于对照组；（２）绝经后女性ＥＨ组Ｅ２水平明显低于对照组。结论血清性激素水平与男性及绝经后女性ＥＨ的发病有关。     

Androgen support of lacrimal gland function

The effects of dihydrotestosterone (DHT) (1 mg/kg) on biochemical parameters related to lacrimal secretion, basal tear flow rate, and pilocarpine-stimulated lacrimal gland fluid secretion, in mature ovariectomized rabbits were studied. The effects of the synthetic estrogen, diethylstilbestrol (DES) (100 μg/kg), on lacrimal gland biochemical parameters in normal mature female rabbits was also studied. Ovariectomy decreased the total serum levels of testosterone (T) by 88.5% and androstenedione by 35.9%, without changing the levels of dehydroepiandrosterone (DHEA) or its sulfate. Ovariectomy caused a significant regression of the lacrimal glands, decreasing total DNA by 35%, and total protein by 22%. DHT treatment of ovariectomized animals prevented lacrimal gland regression, increasing total gland DNA (31%) and total protein (18%). DHT treatment also increases Na⁺,K⁺-ATPase activity (29%) and ?-adrenergic receptor binding sites (23%) compared to the ovariectomized group. DHT increased pilocarpine stimulated lacrimal gland fluid secretion (13.26±1.47 μL/min) compared to the ovariectomized group (7.72±0.41 μL/min), but DHT treatment paradoxically decreased basal tear flow rate (1.02±0.04 μL/min) as compared to the ovariectomized rabbits (1.96±0.12 μL/min). DES decreased the total serum T from 59.33±10.54 pg/mL to 21.5±6.06 pg/mL. DES decreased total Na⁺,K⁺-ATPase by 12% and increased ?-adrenergic receptor binding sites by 83.3%. These results suggest that androgens play a major role in supporting lacrimal gland secretory function. Additionally, they suggest that estrogens may influence certain aspects of lacrimal functions, although it is not clear to what extent those actions are elicited directly or indirectly.     

雄激素与老年男性颈动脉粥样硬化的研究

目的探讨老年男性颈动脉粥样硬化与雄激素水平的关系。方法选择100例老年男性患者,根据多普勒超声测定的颈动脉内膜中层厚度(IMT)分为动脉粥样硬化组和无颈动脉粥样硬化组,并检测血清睾酮(T0)水平。结果100例老年男性患者中,66例发生颈动脉粥样硬化,老年男性颈动脉粥样硬化组的T0水平[(4.52±0.82)μg/L]明显低于无颈动脉粥样硬化组[(5.56±0.92)μg/L,P<0.01],IMT与T0水平呈负相关,T0与高密度脂蛋白胆固醇呈正相关,与脂蛋白呈负相关。结论老年男性颈动脉粥样硬化与雄激素水平有密切关系,雄激素补充治疗可能为降低老年男性动脉粥样硬化的发生提供新的方法。     

Neonatal screening of beta-thalassemias by thin layer isoelectric focusing

As an alternative to the recently proposed screening for beta-thalassemias by isoelectric focusing (IEF) of denatured globin chains in urea-detergent gels [6], IEF of intact hemoglobins, obtained from umbilical cord blood in neonatal units, is reported here. For maximum separation, IEF should be performed in nonlinear pH gradients, in gels containing 0.2 M beta-alanine and 0.2 M 6-amino caproic acid, which flatten the pH gradient around pH 7, thus increasing the resolution between HbA and HbFac. The method can unambiguously detect homozygous and heterozygous beta-thalassemic conditions. A bimodal distribution of HbA at birth has been found: In heterozygous patients, HbA values of 9.02% (range 6.8-9.98%) have been found while in normal newborns HbA levels of 20.34% (range 11.02-30.6%) have been demonstrated.     

Endocrinology: The impact of cigarette smoking on the plasma concentrations of gonadotrophins, ovarian steroids and androgens and upon the metabolism of oestrogens in the human female

This study compares the plasma gonadotrophin, oestradiol, andandrogen and salivary progesterone concentrations in a singlemenstrual cycle between 25 normal pre-menopausal women who smokecigarettes and 21 who are non-smokers. The effect of smokingon luteinizing hormone (LH) pulsatility and the urinary excretionof oestrogens is also described. Cigarette smoking did not consistentlysuppress LH pulsatility. There was no significant differencein the length of either the follicular or luteal phases. Therewere no significant differences in the mean plasma oestradiolconcentrations in the follicular phase in smokers compared tonon-smokers. There were no significant differences in the meansalivary progesterone concentration in the luteal phase in smokerscompared to non-smokers. There was no significant differencein plasma concentrations of testosterone, androstenedione anddehydroepiandrosterone sulphate. There was also no significantdifference between the urinary concentrations of oestradiol,oestrone or oestriol. We have been unable to demonstrate a detrimentaleffect of cigarette smoking on any of the important endocrinecharacteristics of the menstrual cycle, and we conclude thatthese data suggest that the anti-oestrogenic effect of smokingdoes not work through alterations in pituitary or follicularendocrine function or in alterations in the metabolism of oestrogens.     

Three cases of androgen-dependent disease associated with myotonic dystrophy

Three cases of androgen-dependent disease in females with myotonic dystrophy are described. Serum androgens in individuals affected by myotonic dystrophy are known to be lower on average than in normal controls. Despite this these three females developed diseases that are androgen dependent, including acne, hidradenitis suppurativa, androgenetic alopecia and keratosis pilaris. These cases support the hypothesis that the peripheral response to androgens rather than absolute circulating levels of androgens is important in androgen-dependent conditions.     

Concentrations of androgens in human benign prostatic hypertrophic tissues incubated for up to three days

Twenty-one samples of surgically removed benign prostatic hypertrophy (BPH) were brought to the laboratory either in an insulated container (ambient temperature) or on ice. They were cleaned and roughly minced at room temperature. In 18 cases, samples of up to 1 g were kept at various temperatures (4 degrees C, c. 20 degrees C, and 37 degrees C) for up to 77 h; some were taken for storage (-70 degrees C) at the beginning and others at various times within this period. In three cases, portions of tissue were incubated in liquid medium in the absence and presence of testosterone. The concentrations of six androgens (testosterone, 5 alpha-dihydrotestosterone (5 alpha-DHT), 5 alpha-androstane-3 alpha, 17 beta-diol, androstenedione, 5 alpha-androstanedione, and androsterone) were measured by radioimmunoassays. The results indicated that in conditions resembling those after death, the BPH tissue content of 5 alpha-DHT falls to a variable degree, while concentrations of 5 alpha-androstane-3 alpha, 17 beta-diol, 5 alpha-androstanedione, and androsterone increase. After 2 to 3 days, the 5 alpha-DHT concentrations remained greater than those reported previously from this laboratory (and others) in normal prostate tissue removed at autopsy.     

Bone Mass Is Preserved and Cancellous Architecture Altered Due to Cyclic Loading of the Mouse Tibia After Orchidectomy

Introduction : The study of adaptation to mechanical loading under osteopenic conditions is relevant to the development of osteoporotic fracture prevention strategies. We previously showed that loading increased cancellous bone volume fraction and trabecular thickness in normal male mice. In this study, we tested the hypothesis that cyclic mechanical loading of the mouse tibia inhibits orchidectomy (ORX)‐associated cancellous bone loss. Materials and Methods : Ten‐week‐old male C57BL/6 mice had in vivo cyclic axial compressive loads applied to one tibia every day, 5 d/wk, for 6 wk after ORX or sham operation. Adaptation of proximal cancellous and diaphyseal cortical bone was characterized by μCT and dynamic histomorphometry. Comparisons were made between loaded and nonloaded contralateral limbs and between the limbs of ORX (n = 10), sham (n = 11), and basal (n = 12) groups and tested by two‐factor ANOVA with interaction. Results : Cyclic loading inhibited bone loss after ORX, maintaining absolute bone mass at age‐matched sham levels. Relative to sham, ORX resulted in significant loss of cancellous bone volume fraction (?78%) and trabecular number (?35%), increased trabecular separation (67%), no change in trabecular thickness, and smaller loss of diaphyseal cortical properties, consistent with other studies. Proximal cancellous bone volume fraction was greater with loading (ORX: 290%, sham: 68%) than in contralateral nonloaded tibias. Furthermore, trabeculae thickened with loading (ORX: 108%, sham: 48%). Dynamic cancellous bone histomorphometry indicated that loading was associated with greater mineral apposition rates (ORX: 32%, sham: 12%) and smaller percent mineralizing surfaces (ORX: ?47%, sham: ?39%) in the final week. Loading resulted in greater BMC (ORX: 21%, sham: 15%) and maximum moment of inertia (ORX: 39%, sham: 24%) at the cortical midshaft. Conclusions : This study shows that cancellous bone mass loss can be prevented by mechanical loading after hormonal compromise and supports further exploration of nonpharmacologic measures to prevent rapid‐onset osteopenia and associated fractures.