Abstract:
:Hypophyseal and ovarian receptors for the neurohormone LHRH (LHRH-R) have been measured in young (3-4 months), middle-aged (8-11 months), constant estrous (CE, 10-14 months) and pseudopregnant (PR, 16-18 months) rats in order to study whether changes in hypothalamic and/or peripheral LHRH-like peptide production might precede and/or accompany the onset of reproductive failure observed in aging rats. Furthermore, we have investigated whether the neural efferent system from the brain to the ovary is affected with aging. The pattern of pituitary LHRH-R modifications during the estrous cycle of middle-aged rats shows lower LHRH-R levels on the second day of diestrus, resulting in a shift of the maximal LHRH binding capacity in the morning of proestrus. On the other hand, when comparing pituitary LHRH-R of animals exhibiting constant vaginal cornification (CVC) or repetitive PP with young estrus rats, no significant difference could be observed. Young rats responded to electrical stimulation (ES) of the medial preoptic area with an acute elevation of LHRH-R while ES performed in CVC, or PP animals resulted in a significant increase of hypophyseal LHRH binding capacity similar to the one observed in young estrous controls, indicating an impairment in the neural signals impinging in the pulse generating system, in old rats, and not an intrinsic defect of the LHRH-R per se. Ovarian LHRH-R concentration is higher in middle-aged cycling animals on the day of vaginal proestrus, compared to levels measured in young animals at any phase of the estrous cycle. Similarly, CE rats displaying CVC as well as PP animals show significantly higher numbers of LHRH-R with no change in affinity, than young estrus rats. CVC and PP rats receiving unilaterally an intraovarian injection of the potent LHRH antagonist, Ac-D-Cl-Phe1,2, D-Trp3, D-Phe6, D-Ala10, LHRH, showed an acute drop of LHRH-R measured within the treated ovary with no significant changes taking place in the vehicle-treated contralateral gland, suggesting that changes of endogenous ovarian LHRH-like peptide might participate in the mechanism(s) responsible for LHRH receptor increase observed in aging rats. In order to investigate the participation of a direct neural efferent pathway in ovarian LHRH-R regulation, young and old rats were subjected to spinal cord transection (above T10-T11). Bilateral transection of the spinal cord in young animals in the morning of proestrous markedly increased ovarian LHRH-R concentration in the afternoon (17.00 h) of the same day.(ABSTRACT TRUNCATED AT 400 WORDS)
journal_name
Neuroendocrinologyjournal_title
Neuroendocrinologyauthors
Marchetti B,Cioni Mdoi
10.1159/000125018subject
Has Abstractpub_date
1988-09-01 00:00:00pages
242-51issue
3eissn
0028-3835issn
1423-0194journal_volume
48pub_type
杂志文章abstract::Estradiol rapidly regulates the activity of arcuate nucleus (ARH) proopiomelanocortin (POMC) neurons that project to the medial preoptic nucleus (MPN) to regulate lordosis. Orphanin FQ/nociceptin (OFQ/N) acts via opioid receptor-like (ORL)-1 receptors to inhibit these POMC neurons. Therefore, we tested the hypothesis ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000443765
更新日期:2016-01-01 00:00:00
abstract::There is evidence that alpha-melanocyte-stimulating hormone (alpha-MSH) has immunomodulatory and anti-inflammatory actions within the brain. In this study, we tested whether these actions are due to inhibition of the synthesis of nitric oxide (NO) and prostaglandins induced by lipopolysaccharide (LPS). Since melanocor...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000079321
更新日期:2004-01-01 00:00:00
abstract::Neuronal nitric oxide synthase, e.g. NADPH diaphorase (NADPH-d), catalyzes formation of the free radical, nitric oxide (NO), and occurs within brain structures that have functional significance for energy fuel homeostasis. The following studies examined whether populations of NADPH-d-positive neurons in the hypothalam...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054417
更新日期:1999-03-01 00:00:00
abstract:BACKGROUND:68Gallium DOTA-PET imaging is preferable to standard somatostatin receptor scintigraphy where available; however, its role in the management of lung carcinoid tumours (LC) remains unclear. METHODS:All consecutive patients with histologically confirmed LC from two ENETS Centres of Excellence were identified ...
journal_title:Neuroendocrinology
pub_type: 杂志文章,多中心研究
doi:10.1159/000472717
更新日期:2018-01-01 00:00:00
abstract::The effect of pinealectomy or immunization against melatonin (Mel) and N-acetylserotonin (NAS) on plasma prolactin (Prl) levels was studied in rats following pineal stimulation induced by blinding or exposure to short photoperiods (1 h light and 23 h darkness daily). Blinding alone or together with pinealectomy or imm...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122650
更新日期:1977-01-01 00:00:00
abstract::The inhibitory effects of pituitary allografts on the prolactin (PRL)-secretory system are presumed to be consequences of the unabated release of PRL by the allografts. In the present studies we used pituitary allografts in the Golden Syrian hamster to address the following questions: (a) Do allografts of adult adenoh...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000127068
更新日期:1996-05-01 00:00:00
abstract::Studies were undertaken to characterize the secretion of corticotropin-releasing factor (CRF) and arginine vasopressin (AVP) into the hypophysial-portal circulation of the conscious sheep. In addition, we examined the temporal relationship between the secretion of these two hypothalamic peptides and the secretion of t...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125141
更新日期:1989-04-01 00:00:00
abstract:INTRODUCTION:An increasing number of middle-aged men are being screened for low testosterone levels and the number of prescriptions for various forms of testosterone replacement therapy (TRT) has increased dramatically over the last 10 years. However, the safety of TRT has come into question with some studies suggestin...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000504445
更新日期:2020-01-01 00:00:00
abstract::The electrical properties of GH3 cells, a transformed line from the rat pituitary, were studied with a current-clamp technique in the presence of triiodothyronine (T3) and reverse triiodothyronine (rT3) and compared with the known effects of T3. rT3 had an effect only in a concentration of 1 microM; action potentials ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125873
更新日期:1991-08-01 00:00:00
abstract::We have previously reported that luteinizing hormone releasing hormone (LH-RH) levels in the medial basal hypothalamus (MBH) of adult male rats castrated for 2 weeks can be raised by testosterone (T) or estradiol (E2) treatment for 3-4 days. The present study was undertaken to determine the time after castration when ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124188
更新日期:1985-09-01 00:00:00
abstract::The response of folliculo-stellate (FS) cells of the anterior pituitary to estrogen has been studied in two strains of rat which differ in estrogen responsiveness. Fischer 344 (F344) rats are highly estrogen-responsive in comparison to Sprague-Dawley (S-D) rats. Ovariectomized adults were implanted with silastic capsu...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125064
更新日期:1988-11-01 00:00:00
abstract::This study was designed to investigate the effects of penfluridol, a potent neuroleptic calmodulin inhibitor, on basal and secretagogue-stimulated secretion of thyroid-stimulating hormone (TSH), growth hormone (GH), and luteinizing hormone (LH). The drug had no effect on basal TSH or LH release, but decreased GH relea...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123548
更新日期:1983-09-01 00:00:00
abstract::Relief of symptoms can be achieved following surgery for growth hormone (GH)-secreting adenomas, as well as after pharmacological therapy with somatostatin analogs. Recently, long-acting somatostatin analog depot formulations, octreotide LAR and lanreotide SR have become available. Somatostatin analogs control GH/insu...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000095535
更新日期:2006-01-01 00:00:00
abstract::Tissue-specific stem cells are uncovered in a growing number of organs by their molecular expression profile and their potential for self-renewal, multipotent differentiation and tissue regeneration. Whether the pituitary gland also contains a pool of versatile 'master' cells that drive homeostatic, plastic and regene...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000100278
更新日期:2007-01-01 00:00:00
abstract::The diuretic action of two new narcotic antagonists, oxilorphan and butorphanol, was studied in rats heterozygous for hereditary hypothalmic diabetes insipidus. Both drugs caused a prompt increase in urine volume and a decrease in urine osmolality with an associated decrease in urinary ADH excretion. The effects appea...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122444
更新日期:1975-01-01 00:00:00
abstract::[125I]-neuropeptide Y receptors were characterized in the rat pituitary gland using quantitative autoradiography. Scatchard analysis of saturation isotherms showed high affinity (Kd 8.5 x 10(-11) M) and single class of binding sites (Bmax 0.22 pmol/mg of protein) in the posterior lobe of the pituitary gland, with no s...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125608
更新日期:1990-10-01 00:00:00
abstract:BACKGROUND/AIMS:Abuse of toluene products (e.g., glue-sniffing) primarily occurs during adolescence and has been associated with appetite suppression and weight impairments. However, the metabolic phenotype arising from adolescent inhalant abuse has never been fully characterised, and its persistence during abstinence ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000493686
更新日期:2018-01-01 00:00:00
abstract::Somatostatin (ST) inhibits gastrointestinal motility and exocrine and endocrine secretions. In animals, ST has been demonstrated to decrease food intake. We investigated, in a randomized double-blind investigation in 10 healthy humans, the effects of an intravenous ST infusion compared to saline on subjective hunger f...
journal_title:Neuroendocrinology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1159/000126831
更新日期:1995-02-01 00:00:00
abstract::Oxytocin (OT) binding sites are modulated by estrogens in several brain regions including the ventromedial hypothalamic nucleus (VMN) in both male and female rats. To further study steroid regulation of OT receptor binding, we examined the effect of androgen replacement in castrated male rats on OT binding with quanti...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125222
更新日期:1989-08-01 00:00:00
abstract::Over the last 10 years, kisspeptins--peptide products of varying lengths encoded by the KISS1 gene--have been found to be key regulators of normal reproductive function throughout life in animals and humans. By activating the kisspeptin receptor [previously known as orphan G protein-coupled receptor 54 (GPR54)], they ...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000439133
更新日期:2015-01-01 00:00:00
abstract::In the present study the effects of intravenously administered corticotropin-releasing hormone (CRH) on the release of proopiomelanocortin (POMC) derivatives such as adrenocorticotropic hormone (ACTH), beta-lipotropin (beta-LPH) and beta-endorphin (beta-END) as well as direct effects of CRH on pain sensitivity were ex...
journal_title:Neuroendocrinology
pub_type: 杂志文章,随机对照试验
doi:10.1159/000091980
更新日期:2005-01-01 00:00:00
abstract::Measurements of electrical activity and intracellular Ca(2+) levels were performed in perforated-patch clamped GH(3) cells to determine the contribution of large-conductance calcium-activated K(+) (BK) channels to action potential repolarization and size of the associated Ca(2+) oscillations. By examining the dependen...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000069509
更新日期:2003-03-01 00:00:00
abstract::The present study provides evidence of a novel neuronal pathway for the control of GnRH secretion involving bradykinin neurons. Bradykinin neurons were shown by immunohistochemistry to be densely localized in several regions of the brain including the cortex, hippocampus and supraoptic nucleus, as well as two regions ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054316
更新日期:1998-04-01 00:00:00
abstract::Many aspects of reproductive neuroendocrine function and sexual behavior are responsive to both androgens and estrogens, suggesting that receptors for these steroid hormones may reside within single cells in brain regions that control reproductive function. We determined the distribution of estrogen receptor-containin...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000127039
更新日期:1995-11-01 00:00:00
abstract::The anterior pituitary is permanently regulated by processes of apoptosis and proliferation in order to maintain tissue homeostasis. Several factors have been implicated in this regulation and lately, prolactin (PRL) has been included into that list. However, since PRL is secreted by anterior pituitary lactotropes, th...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000354701
更新日期:2013-01-01 00:00:00
abstract::Hypertension in male and aging female rodents is associated with glutamate-dependent plasticity in the hypothalamus, but existing models have failed to capture distinct transitional menopausal phases that could have a significant impact on the synaptic plasticity and emergent hypertension. In rodents, accelerated ovar...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000446073
更新日期:2017-01-01 00:00:00
abstract::Three control point enzymes of the Embden-Meyerhof pathway, hexokinase (HK), phosphofructokinase (PFK) and pyruvate kinase (PK) were measured by quantitative histochemical methods in individual hypothalamic nuclei of adult neonatally androgenized female rats. HK activity was significantly increased in anterior hypotha...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122715
更新日期:1977-01-01 00:00:00
abstract::Vasopressin and oxytocin modulate memory processes which effects are dissociated from the typical peripheral endocrine effects of these neuropeptides. Recently, vasopressin has been implicated in the regulation of body temperature. In view of this, experiments were designed to determine whether the antipyretic effect ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123554
更新日期:1983-10-01 00:00:00
abstract::Male Turkish hamsters received horizontal knife cuts within the hypothalamus to investigate the role of afferent and efferent projections of the paraventricular nucleus (PVN) in seasonal regulation of endocrine function. Following surgery, the animals were exposed to either a long (16 h light/8 h dark) or a short (8 h...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126159
更新日期:1992-04-01 00:00:00
abstract::TRPM8 is a member of the melastatin-type transient receptor potential ion channel family. Activation by cold or by agonists (menthol, icilin) induces a transient rise in intracellular free calcium concentration ([Ca(2+)](i)). Our previous study demonstrated that Ca(2+)-permeable cation channels play a role in IGF-1-in...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000101693
更新日期:2007-01-01 00:00:00