Effects of intracerebroventricular infusion of genistein on gonadotrophin subunit mRNA and immunoreactivity of gonadotrophins and oestrogen receptor-alpha in the pituitary cells of the anoestrous ewe

The present study was designed to demonstrate whether genistein, a synthetic phytoestrogen, infused into the third ventricle of the brain could affect the gonadotrophic cells regarding the presence of oestrogen receptor-alpha immunoreactivity and gonadotrophin subunit mRNA hybridising reaction in the ewe. Ewes (n=7), aged 2 years, in early anoestrous season were infused with Ringer-Locke solution (control, n=3) or 10 microg/100 microl/h of genistein (n=4) into the third ventricle over a 5 h period and slaughtered the following morning. Immunoreactivity of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and oestrogen receptor-alpha (ERalpha) was determined in the adenohypophysis by immunohistochemistry using antibodies raised against LHbeta, FSHbeta, and ERalpha. Messenger RNA analyses were performed by non-isotope in situ hybridisation using sense and antisense riboprobes produced from beta subunits of LH and FSH cDNA clones. Computer image analysis was used to determine the percent of cells exhibiting immunohistochemical and/or hybridising reaction. It was found that in ewes infused with genistein, the percentage of LH-positive cells and the density of immunoreactive-LHbeta material decreased significantly (P相似文献   

Prepubertal changes in the synthesis, storage and release of growth hormone and luteinising hormone and in the immunoreactivity of oestrogen receptor-alpha in lamb pituitary cells. A morphofunctional study

The present study was designed to determine the changes in the synthesis, storage and release of luteinising hormone (LH) and growth hormone (GH) in the hypophyseal cells by investigating the presence of oestrogen receptor-alpha (ERalpha) in developing prepubertal female lambs. The experiment was carried out on 14 prepubertal (17-week-old) and 14 peripubertal (32-week-old) ovary-intact lambs. Morphofunctional changes in the cells of the adenohypophyseal population were assayed with immunohistochemistry (IH), in situ hybridisation (ISH), Real-time PCR and radioimmunoassay (RIA). Blood samples (n=14) were taken every 2 weeks from 17 to 32 weeks of age for estimation of GH and LH by RIA. Computer image analysis was used to determine the percent of cells exhibiting IH and/or ISH reaction. The percentage of cells stained for LHbeta and GH increased for both LH- and GH-producing cells and were higher (P<0.001) in the peripubertal than prepubertal group. The percentage of mRNA LHbeta-expressing cells decreased and were lower for the peripubertal (P<0.001) than prepubertal group. The GH mRNA in pituitaries of prepubertal lambs was higher in comparison to peripubertal ones (P<0.001). The percentage of ERalpha positive cells increased significantly (P<0.001) in peripubertal compared to prepubertal lambs and this increase was significant (P<0.001) in both LH- and GH-producing cells. Plasma LH concentrations increased from 27 weeks of age, while GH concentrations gradually decreased from 17 weeks of age (P<0.05). The histomorphological changes in the LH- and GH-producing cells reflect the increasing pattern of the regulation of secretory processes of these hormones and an escalating regulatory role of oestrogen in the physiology of these cells during the prepubertal period. These results support the involvement of both hormones in the events leading up to puberty.     

The effect of intracerebroventricular infusions of leptin on the immunoreactivity of neuropeptide Y and gonadotrophin releasing hormone neurons in the hypothalamus of prepubertal sheep in conditions of short fasting

In the study we evaluated the effects of infusion of exogenous leptin to the third ventricle of the brain on the expression of immunoreactive (ir) neuropeptide Y (NPY) neurons in the hypothalamus and ir gonadotrophin releasing hormone (GnRH) nerve terminals in the median eminence of prepubertal lambs in the conditions of short fasting. Merino female sheep (n=16) were randomly divided into four groups, two fed with standard feeds and two fasted for 72 h. One standard and one fasted groups were infused with Ringer saline (controls), remaining standard and fasted groups with leptin (25 microg/120 microl/h), for 4 h during three consecutive days, and then slaughtered. Ir NPY and ir GnRH were localized by immunohistochemistry using specific polyclonal antibodies. Detection of both hormones was followed by the image analysis and expressed as the percent area stained and integral density of immunostaining. In the hypothalami from all groups the ir NPY perikarya and varicose nerve fibers were localized in three distinct sub-areas, in the arcuate (ARC), paraventricular and periventricular nuclei. In fasted sheep the percent area and integral density for immunoreactivity of NPY increased significantly (P<0.001) in three sub-areas compared to the standard-fed animals. Leptin infusion lowered the both parameters (P<0.001) but solely in the ARC NPY population of fasted sheep. The percent area and integral density of immunostaining for ir GnRH in fasted sheep revealed the augmentation (P<0.001) compared to standard-fed sheep. Leptin infusions diminished (P<0.001) both parameters in fasted, without effects in standard-fed lambs. In conclusion, the enhanced by fasting immunoreactivity of the ARC NPY perikarya and varicose nerve fibers and restrained immunoreaction of GnRH terminals in the median eminence were reversed by exogenous leptin. It is suggested that leptin can affect GnRH release via ARC NPY neurons in conditions of deficit of nutrients in prepubertal, female lambs.     

Effects of maternal deprivation on the adrenocorticotrophic and gonadotrophic axes in the hypothalamo-pituitary unit of preweanling female sheep: the histomorphometric approach

This study was designed to investigate the histochemical effects of maternal deprivation on the adrenocorticotrophic and gonadotrophic axes in the hypothalamo-pituitary unit of preweanling lambs. Twelve-week-old female lambs were divided into either the control (lambs reared under undisturbed maternal conditions; n=3) or the maternally deprived group (lambs separated for three days from their dams; n=3). The corticotrophin-releasing hormone (CRH) and gonadotrophin-releasing hormone (GnRH) in the median eminence and the adenohypophyseal adrenocorticotrophin (ACTH), gonadotrophins (LH and FSH) and mRNAs for their beta-subunits were investigated using the immunohistochemistry or hybridohistochemistry. In maternally deprived lambs, the percentage of the area occupied by immunoreactive (ir)-CRH nerve terminals was lower (P<0.05) and the percentage of the adenohypophyseal area (PAA) occupied by ir-ACTH cells was higher (P<0.05) compared with the control lambs. In the hypothalamo-gonadotrophic axis of maternally deprived lambs the percentage of area occupied by ir-GnRH nerve terminals was higher (P<0.05) and the PAA occupied by ir-FSHbeta cells was lower (P<0.05) in comparison with controls. The PAA occupied by gonadotrophs detected using hybridohistochemistry was higher (P<0.05) for LHbeta-mRNA in contrast to a lower (P<0.05) percentage for FSHbeta-mRNA in maternally deprived lambs compared with those staying with dams. In conclusion, maternal deprivation affected the accumulation of CRH and ACTH. The different and more striking alterations in FSH synthesis and storage in comparison with those concerning LH were observed in maternally deprived lambs. Thus, rupture of the preweanling young-mother social contact can affect the gonadotroph population activity, especially that relating to FSH-producing cells in the infantile female sheep.     

三叶因子3在大鼠腺垂体嗜色细胞中的定位

目的探讨三叶因子3(TFF3)在腺垂体远侧部嗜酸性细胞和嗜碱性细胞中的表达,明确TFF3在远侧部的分布。方法采用相邻切片的免疫组织化学染色,在相邻切片上分别显示TFF3/生长激素(GH)、TFF3/催乳素(PRL)、TFF3/促甲状腺激素(TSH)、TFF3/促肾上腺皮质激素(ACTH)、TFF3/卵泡刺激素(FSH)、TFF3/黄体生成素(LH)的表达。结果 TFF3和各嗜色细胞的免疫反应产物为棕黄色,主要位于细胞质,ACTH免疫阳性信号在胞膜也有表达,主要分布在腺垂体的远侧部。邻片显示TFF3存在于部分GH、PRL、TSH、ACTH、FSH、LH细胞,分别占19.4%、22.4%、9.2%、6.5%、35.7%、8.3%,以FSH最多,PRL、GH次之。结论垂体远侧部TFF3可分别表达于GH、PRL、TSH、ACTH、FSH、LH细胞。     

Microcomputer-controlled device for delivering hormone stimulation to cell suspensions in perifusion: release of luteinising hormone from sheep pituitary cells

A microcomputer-controlled device for delivering arbitrarily complex pulse trains of stimulating hormones or other chemicals simultaneously to as many as 15 samples of dispersed cells or other biological preparations in perifusion is described Effluents containing substances released in response to the stimulating signals are collected automatically in fractions for analysis later. The use of the device is illustrated by applying stimulatory signals of gonadotrophin releasing hormone GnRH to dispersed sheep anterior pituitary cells and analysing the resulting output of luteinising hormone LH. continuous application of the stimulatory signal caused desensitisation (diminished output), showing the need for a recovery period between pulses. A long stimulatory pulse produced less LH per unit of releasing hormone than did short pulses, indicating the importance of the rising edge in the release mechanism. Above a threshold level, increased height of the GnRH pulse had negligible effect on LH output.     

Seasonal changes in the hypothalamo‐pituitary‐testes axis of the japanese wood mouse (Apodemus speciosus)

Seasonal changes in the hypothalamo‐pituitary‐testes axis of the Japanese wood mice (Apodemus speciosus) were studied. The testes, epididymis, pituitary and hypothalamus were compared between mice in the breeding season (July) and non‐breeding season (October) using morphological techniques, and the plasma testosterone level was evaluated by enzyme immunoassay. Significant differences in these tissues were observed between the breeding season and the non‐breeding season. Specifically, differences in the non‐breeding season included 1) a decline in testicular and epididymal weights, arrest of spermatogenesis and decrease of serum testosterone concentration; 2) a decrease in the number of luteinizing hormone (LH)‐, follicle stimulating hormone (FSH)‐, prolactin (PRL)‐, and growth hormone (GH)‐immunoreactive cells, and decrease in the size of FSH, PRL, and GH‐immunoreactive cells; and 3) an increase in the size of gonadotropin‐releasing hormone (GnRH)‐immunoreactive neurons. Our findings indicate that the male adult Japanese wood mouse exhibits unique seasonal changes in the hypothalamo‐pituitary‐testes axis which are not found in laboratory mice. Anat Rec 260:366–372, 2000. © 2000 Wiley‐Liss, Inc.     

Current concepts on ultradian rhythms of luteinizing hormone secretion in the human

A cardinal physiological feature of anterior pituitary hormonesecretion is its pulsatile mode of signalling to remote targettissues. The pulsatile release of anterior pituitary hormonesis orchestrated by episodic neuronal activation of hypothalamiccontrol centres, which release relevant effector molecules intermittently.The anterior pituitary gland in turn secretes hormones in ultradianbursts, and thereby communicates with and governs the functionof peripheral target organs. In the case of the reproductiveaxis, the release of gonadotrophin-releasing hormone (GnRH)from the hypothalamus in intermittent secretory bursts is aprimary neural determinant of pulsatile gonadotrophin [luteinizinghormone (LH) and follicle stimulating hormone (FSH)] secretion.In men, women and pubertal children, the pulsatile mode of GnRHrelease is critical for sustained physiological function ofgonadotroph cells and is an absolute prerequisite for reproductivecapability. Furthermore, various clinical pathophysiologicalstates, such as inadequate nutrient intake, stress and uraemia,may dramatically impair the pulsatile release of gonadotrophichormones. Here, we review some recent studies in reproductive(neuro)endocrinology that illustrate physiological regulationand pathophysiological disruption of pulsatile LH signallingin the human. Keywords: FSH/gonadotrophin/LH/men/pulsatile/women     

Effects of intracerebroventricular infusion of genistein on gonadotrophin subunit mRNA and immunoreactivity of gonadotrophins and oestrogen receptor-α in the pituitary cells of the anoestrous ewe

The present study was designed to demonstrate whether genistein, a synthetic phytoestrogen, infused into the third ventricle of the brain could affect the gonadotrophic cells regarding the presence of oestrogen receptor-α immunoreactivity and gonadotrophin subunit mRNA hybridising reaction in the ewe. Ewes (n = 7), aged 2 years, in early anoestrous season were infused with Ringer–Locke solution (control, n = 3) or 10 μg/100 μl/h of genistein (n = 4) into the third ventricle over a 5 h period and slaughtered the following morning. Immunoreactivity of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and oestrogen receptor-α (ERα) was determined in the adenohypophysis by immunohistochemistry using antibodies raised against LHβ, FSHβ, and ERα. Messenger RNA analyses were performed by non-isotope in situ hybridisation using sense and antisense riboprobes produced from β subunits of LH and FSH cDNA clones. Computer image analysis was used to determine the percent of cells exhibiting immunohistochemical and/or hybridising reaction. It was found that in ewes infused with genistein, the percentage of LH-positive cells and the density of immunoreactive-LHβ material decreased significantly (P ≤ 0.001), but the percentage of mRNA LHβ-expressing cells and the intensity of the hybridisation signal increased significantly (P ≤ 0.001), compared to the vehicle-infused animals. The genistein infusions had no effect on the immunoreactivity of FSH cells or on the expression of mRNA for FSHβ. The percentage of ERα-positive cells increased significantly after genistein infusions (P ≤ 0.001) and this increase was significant in the LH but not in FSH cells (P ≤< 0.001). In conclusion, we suggest that genistein can stimulate the expression of immunoreactive ERα in the pituitary LH-cells but not in FSH-cells and change the endocrine activity of LH-producing cells of anoestral ewes.     

Endocrinology: On the dynamics between gonadotrophin surge-inhibiting factor and gonadotrophin releasing hormone (GnRH): role of self-priming and desensitization in the luteinizing hormone response to GnRH after follicle stimulating hormone treatment

The effects were studied of follicle stimulating hormone (FSH)-inducedproduction of gonadotrophin surge-inhibiting factor (GnSIF)on three phases of the pituitary responsiveness to gonadotrophinreleasing hormone (GnRH): the unprimed, primed and desensitizedphases. Rats were injected with FSH on two occasions duringthe oestrous cycle. Spontaneous luteinizing hormone (LH) surgeswere measured as well as GnRH-induced LH surges on the day ofpro-oestrus during infusions with 100–4000 pmol GnRH/rat/10h, in phenobarbital blocked rats. The spontaneous LH surgeswere attenuated or completely inhibited by the FSH treatment.FSH suppresses and prolongs the unprimed LH response and delaysGnRH self-priming, especially during infusions with low concentrationsof GnRH. This treatment does not affect the total LH response(area under curve) to the highest concentrations of GnRH andafter ovariectomy. On the other hand, this response is suppressedduring infusions with the lower concentrations of GnRH. Hence,FSH, via GnSIF, delays maximal priming of the LH response toGnRH, whereas the suppression of LH release is a consequenceof the GnRH-induced progressed state of desensitization. Theinconsistent effects of FSH on the mid-cycle LH surges are explainedas a result of the interaction between the relative strengthsof GnRH and GnSIF.     

Endocrinology: Influence of serum follicle stimulating hormone to luteinizing hormone ratio during buserelin acetate-induced pituitary desensitizafion on ovarian response to exogenous gonadotrophins in an in-vitro fertilization and embryo transfer programme

We investigated the effect of endogenous gonadotrophins duringpituitary desensitization with gonadotrophin-releasing hormoneagonist (GnRHa) on ovarian responsiveness or the outcome ofin-vitro fertilization (IVF) and embryo transfer. The resultsof 67 women who participated in the IVF programme at NagasakiUniversity Hospital, Japan, were analysed retrospectively. Allwomen received GnRHa from the third day of the menstrual cycle,and ovarian stimulation with exogenous gonadotrophins was initiatedwhen the serum oestradiol concentration decreased to <30pg/ml. The serum follicle stimulating hormone (FSH)/luteinizinghormone (LH) ratio, rather than serum FSH or LH concentrationsduring GnRHa-induced pituitary desensitization, showed a significantpositive correlation with age and the total dose of exogenousgonadotrophins. The FSH/LH ratio also showed a significant negativecorrelation with oestradiol response and the number of retrievedoocytes, and was significantly lower in pregnant women comparedwith the non-pregnant group during pituitary desensitization.Our results indicate that, even under pituitary desensitizationwith GnRHa, the serum FSH/LH ratio influences individual ovarianresponsiveness and the state of the intra-ovarlan hormonal environment.Our results suggest that the FSH/LH ratio may be a useful clinicalpredictor of the ovarian response to exogenous gonadotrophinsunder pituitary desensitization.     

In vitro pituitary prolactin, growth hormone and follicle stimulating hormone secretion during sexual maturation of female rats primed with melatonin

The influence of in vivo melatonin administration on in vitro pituitary follicle stimulating hormone (FSH), growth hormone (GH) and prolactin secretion, as well as the possible influence of dopamine (DA) were evaluated in prepubertal (31-day-old), pubertal (33-day-old) and adult female rats at diestrus phase of the sexual cycle. The in vitro pituitary hormone secretions were evaluated at basal rate for the first hour of incubation only, in Krebs Ringer phosphate (KRP) (I1) and after a second hour of incubation with KRP (I2) or with KRP+DA (I2 plus DA). I1PRL secretion was significantly higher in 33-day-old control and melatonin treated (MEL) rats as compared to I2 periods. However, in 31-day-old rats I1 secretion was higher than in the I2 or I2+DA periods, in MEL rats. In vitro GH secretion was significantly higher at I1 than during I2 periods in the control 31- and 33-day-old groups, but not in MEL rats. The only significant effect of DA was the elevation of GH in prepubertal MEL rats. In vitro FSH release was increased by melatonin in 31- and 33-day-old female rats. No differences in PRL, GH and FSH secretion were found in adult rats. In conclusion, the results show that melatonin effects upon in vitro pituitary gland activity are reproductive-stage-dependent modifying the secretory capacity of the lactotrop, gonadotrop and somatotrop during prepubertal and pubertal ages but not in adult rats studied at a quiescent phase of the sexual cycle.     

The effect of recombinant follicle stimulating hormone (Gonal-F) on endogenous luteinizing hormone secretion in women

Parenteral administration of follicle stimulating hormone (FSH) has been shown to lower luteinizing hormone (LH) concentrations in women undergoing ovulation induction. This study was designed to explore the physiological mechanism of this effect. Seven healthy women were recruited into a double-blind placebo-controlled study. LH secretion, after the administration of variable i.v. boluses (37.5, 75 and 150 IU) of recombinant FSH (Gonal-F), was evaluated. LH was measured at 10 min intervals for 2 h before and 4 h after the FSH/placebo infusion. LH pulse frequency and amplitude were evaluated and there was no significant difference between control and trial cycles for each subject. A linear regression analysis revealed that in the group receiving 150 IU FSH, the mean plasma LH concentration decreased significantly due to a reduction tonic LH secretion. This could be a result of the suppression of secretion or an alteration of clearance. This decrease was not seen in the other dosage groups, revealing that above a dosage threshold, FSH reduced non-pulsatile LH secretion. Therefore the effect of FSH in this study exposed the likely presence of two components of LH concentration: an FSH-sensitive, non-pulsatile tonic secretion and a gonadotrophin-releasing hormone-stimulated, pulsatile release that is unaffected by FSH. Although an indirect effect involving ovarian regulation is not excluded, the rapidity of the effect suggests that FSH acts directly on the pituitary gland.      

Detection of gonadotropin-releasing hormone receptor in normal human pituitary cells and pituitary adenomas using immunohistochemistry

Gonadotropin-releasing hormone (GnRH), which is a well-known regulator of gonadotroph function, has recently been considered to be a paracrine factor involved in the control of somatotroph, lactotroph, and corticotroph cells. GnRH action is initiated by binding to a specific cell surface receptor, the gonadotropin-releasing hormone receptor (GnRHR), which is expressed by follicle-stimulating hormone/luteinizing hormone (FSH/LH) cells. Using in situ hybridization techniques, GnRHR messenger ribonucleic acid (mRNA) has recently been detected in normal human anterior pituitary gland and in various pituitary adenomas, including FSH/LH-cell, growth hormone (GH)-cell, adrenocorticotropic hormone (ACTH)-cell, and null-cell adenomas. However, immunohistochemical studies indicating the specific cell distribution of GnRHR in normal pituitary cells have never been reported. The aim of the present investigation was to evaluate the immunohistochemical expression of GnRHR in different types of normal pituitary cells and related tumors. Using double-label immunohistochemical techniques on formalin-fixed and paraffin-embedded tissues and specific antibodies directed against pituitary hormones and GnRHR, we found GnRHR immunoreactivity not only in FSH/LH cells, but also in GH- and thyroid-stimulating hormone (TSH) cells. GnRHR was detected in FSH/LH-cell, GH-cell, mixed GH- and prolactin (PRL)-cell, and α-subunit (α-SU)/null-cell adenomas. The findings of this study suggest that the interaction between GnRH and GnRHR may play a role in paracrine/autocrine regulation of different types of normal pituitary cells and pituitary adenomas. Received: 24 January 2000 / Accepted: 12 April 2000     

Prepubertal rat thymus secretes a factor that modulates gonadotropin secretion in cultured rat pituitary cells

Thymus development and function are influenced by endocrine glands. On the other hand, the absence of thymus results in endocrine disturbances. The aim of the present paper is to investigate the direct influence of thymus products on the gonadotropin secretion of rat pituitary cells in culture. In this study, a chromatographic fraction obtained from the acetonic powder of thymus from 14-15 day-old rats (TF) increased the GnRH stimulated LH and FSH secretion from cultured pituitary cells, but had no effect on the basal secretion of these gonadotropins. The addition of incubation medium from thymus (TIM) to cultured pituitary cells further enhanced GnRH stimulated FSH and LH production, the effect was dose related. The GnRH potentiating effect of thymus incubation medium was also present in a chromatographic fraction of around 28 Kd obtained from this medium. These data suggest that the prepubertal thymus contains and secretes a factor that modulates pituitary cells secretion potentiating the Gn-RH effect.     

Endocrinology: Different follicle stimulating hormone/luteinizing hormone ratios for ovarian stimulation

The aim of the present study was to investigate whether reducingthe amount of luteinizing hormone (LH) in gonadotrophic preparationsimpairs follicular growth in in-vitro fertilization (IVF) cyclesduring suppression of endogenous LH levels. A selected groupof 20 IVF patients was randomly divided into two groups. Onegroup was treated with Org 31338 [follicle stimulating hormone(FSH)/LH 3: 1], the other group with Metrodin® (purifiedFSH), both during pituitary down-regulation with buserelin.A fixed daily dose of 150 IU FSH i.m. was given. Serum concentrationsof FSH, LH, oestradiol and progesterone were determined frequentlyand serial ultrasound examinations were performed. Multiplefollicular growth with concomitant rise of oestradiol levelswas observed in all cycles. The duration of the stimulationphase was shorter in the group treated with Org 31338 than inthe group treated with Metrodin. The number of follicles andoocytes and the fertilization rate was larger and the mean embryoquality was higher in the Org 31338 group, but the differencesdid not reach statistical significance. No significant differenceswere found in hormonal values. In women with normal endocrineprofiles, lowering of the LH activity in gonadotrophic preparationsduring gonadotrophin-releasing hormone agonist treatment resultsin adequate ovarian stimulation. However, a preparation withsome LH needed a shorter stimulation than a purified FSH preparation.Whether the other beneficial effects of Org 31338 also occurin a larger population needs further investigation.     

Distribution and concentration of immunoreactive parathyroid hormone in brain and pituitary of sheep

Summary We have studied the presence of immunoreactive parathyroid hormone (PTH) in the central nervous system and pituitary of sheep. The PTH concentrations were measured radioimmunologically by two different region-specific antibodies. We could demonstrate PTH in various areas of the brain, whole pituitary, parathyroid glands and plasma of 21 sheep. Measurable concentrations of the two different parathyroid regions (35–84 and 44–68 amino acids fragments) were found in all samples.Abbreviations ACTH Adrenocorticotrophic hormone - CT Calcitonin - CSF Cerebrospinal fluid - CPM Counts per min - Leu-ENK Leucine-enkephalin - Met-ENK Methionine-enkephalin - PTH Immunoreactive parathyroid hormone - RIA Radioimmunoassay - TSH Thyroid stimulating hormone - T₄ Thyroxine - T₃ Triiodothyronine     

Border disease. Virus-induced decrease in thyroid hormone levels with associated hypomyelination

Border disease (BD) was induced in lambs by inoculation of their dams at 50 days gestation with Border disease virus (BDV) isolate #31. At birth, the clinically affected lambs had diffuse spinal cord hypomyelination, confirmed by immunocytochemical staining for myelin-associated glycoprotein and myelin basic protein. In the BD lambs, large numbers of thyroid follicular epithelial cells and scattered pituitary cells contained BDV antigen by immunofluorescence staining. Double labeling techniques demonstrated the BDV-infected pituitary cells to contain growth hormone, adrenocorticotrophic hormone, prolactin, or luteinizing hormone. Cells containing thyroid stimulating hormone were rare and were not positive for BDV antigen. Infection of the pituitaries and thyroid glands caused no detectable morphologic changes as compared to controls. The BD lambs had statistically significantly (p less than 0.05) lower mean serum concentrations of thyroxine and L-3,3',5-triiodothyronine as compared to age-matched uninfected controls. Similar significant differences in the mean plasma levels of growth hormone and thyroid stimulating hormone were not found. In addition, the BD lambs had a statistically significant (p less than 0.05) lower mean activity of the myelin-associated, thyroid hormone dependent enzyme, 2',3'-cyclic nucleotide-3'-phosphodiesterase in spinal cord tissue. Although not conclusive, these results indicate that the hypomyelination in BD may be due to depressed levels of circulating thyroid gland hormones secondary to a noninflammatory and noncytolytic infection of the thyroid gland by BDV. This is one of the first reports indicating that a virus-induced hormonal alteration may cause a congenital lesion in animals.     

A sensitive and specific immunoradiometric assay (IRMA) for human thyroid stimulating hormone

A liquid phase "two-site" immunoradiometric assay (IRMA) specific for human thyroid stimulating hormone (hTSH) is described. The assay is based on the simultaneous addition of affinity purified sheep anti hTSH IgG-I 125 and rabbit anti hTSH antiserum to standards and unknowns followed by 4h incubation at room temperature. The separation of free labelled sheep IgG-I125 from that bound to hTSH is achieved by the addition of sheep anti-rabbit IgG Fc fragment antiserum. The radiolabelled sheep anti-hTSH IgG-I 125 was pretreated with solid phase urinary postmenopausal gonadotropins to remove cross reaction with FSH and LH. The assay is specific for hTSH and no cross reaction with the other anterior pituitary glycoproteins or protein hormones has been found. In addition it is characterized by a wide operating range, rapid equilibration of reactants and high sensitivity (0.02 microU/ml). The precision of dose estimates was less than 10% between 0.25-2.5 microU/ml and less than 2.5% over the range 2.5-60 microU/ml.     

卵泡刺激素受体在山羊颈胸神经节的分布

目的探讨卵泡刺激素(FSH)是否影响心肺功能活动的自主神经调节。方法取雄性和雌性成年山羊的颈胸神经节各5对,经免疫组织化学SP法染色后,观察FSH受体在山羊颈胸神经节的分布特点。结果在颈胸神经节内,FSH受体免疫阳性产物主要存在于神经元的细胞质和细胞膜,为强阳性或中等阳性染色,而细胞核呈空泡状,不着色。此外,在神经节内的支持细胞、过路纤维、施万细胞以及血管内皮细胞中FSH受体呈弱阳性染色,有少量分布。图像分析表明,该神经节内神经元胞体的FSH受体相对表达量极显著高于其他非神经元胞体结构(P0.01)。结论颈胸神经节中神经元细胞是FSH作用的主要靶细胞,提示FSH可能通过影响该神经节的神经元活动,从而影响其发出的交感节后神经而调节心肺功能活动。