ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

A new syndrome of constipation in association with ovarian carcinoid tumors as a possible consequence of ectopic peptide YY secretion and evidence of ectopic endothelin production have been described. Two papers describe the adverse prognosis in small cell lung cancer that is conferred by ectopic corticotropin production, and a new hypothesis of cortisol inactivation overload has been proposed to explain the excessive mineralocorticoid effects often seen in the ectopic corticotropin syndrome. At a more basic level, the glucocorticoid resistance of ectopic corticotropin-secreting tumors has been explored, and the potential of bromocriptine in inhibiting the peptide output of small cell lung cancer cells is reported. A further report on the use of octreotide as a treatment for ectopic corticotropin-secreting tumors is disappointing, but a single case report of a synergistic effect of this drug with interferon may point the way for future therapeutic possibilities.

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The cytokines are a group of pluripotential proteins that affect the functioning of the immune system as well as the hypothalamic-pituitary axis. This review summarizes recent findings related to the effects of interleukin (IL)-1, IL-2, IL-6, and tumor necrosis factor-α (TNF-α) on the neuroendocrine system Cytokine binding sites on anterior pituitary cells (IL-6, IL-1, IL-2) and in the hypothalamus (IL-6, IL-1) suggest a role for these factors in the regulation of hormone secretion. IL-6, IL-1, IL-2, and TNF-α each regulate the synthesis and release of anterior pituitary hormonesin vitro.In addition, the cytokines enhance hypothalamic-releasing factor production by the medial basal hypolhalamus and, at least for IL-6, the median eminence as well. The neuroendocrine mechanisms activated by central and peripheral administration of IL-1 are probably unrelated. Multiple points of interaction with the neuroendocrine system and redundancy of effects suggest that a variety of inflammatory insults distinguished by different cytokine patterns may still result in a prototypical activation of the hypothalamic-pituitary-adrenal axis.

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Advances in hormone-dependent malignancy have led to the introduction of new nontoxic endocrine therapies and meta-analyses and to the more widespread use of adjuvant therapies. Developments in molecular biology have brought us nearer to our hopes for gene therapy in this turnover group.

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Proopiomelanocortin is the pituitary precursor of circulating corticotropin, α-melanocyte-stimulating hormone, and β-endorphin. Proopiomelanocortin is also produced in the brain, in neurons of the arcuate nucleus of the hypothalamus, and in the neurons of the commissural nucleus of the solitary tract of the brainstem; however, the functions of proopiomelanocortin peptides in the brain are presently less clear. The recent cloning of the adrenocortical corticotropin receptor and melanocyte α-melanocyte stimulating hormone receptor has led for the subsequent discovery of two distinct neural melanocortin receptors, that is, receptors that recognize the nonopiate proopiomelanocortin-derived peptides. The unique distribution of the neural melanocortin 3 and melanocortin 4 receptors, primarily in the hypothalamus limbic system, and brain-stem, suggests complex roles for melanocortin peptides in the central nervous system. The cloning of these molecules should help clarify the pharmacology and sites of action of melanocortin peptides in the brain. Ultimately, these cloned receptors may also be important tools in defining the roles that proopiomelanocortin plays in the central nervous system.

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

During the past year, numerous discoveries have been made regarding the control of gonadotropin secretion. Perhaps most important is the innate pulsatility of cloned hypothalamic gonadotropin-releasing hormone (GnRH)-secreting neuronal cell lines. This model and other data indicate that signalling via voltage-sensitive Ca2+channels is integral to pulsatile GnRH release, and that GnRH secretion is enhanced by physiologic glucose concentrations, neuropeptide Y, and hypothalamic adrenergic β1receptor stimulation. GnRH release is decreased by gamma aminobutyric acid receptor A, corticotropin-releasing hormone, and testosterone. At the pituitary level, GnRH pulse amplitude and frequency, testosterone, interleukin, corticotropin-releasing hormone, and progesterone modulate follicle stimulating hormone (FSH) and luteinizing hormone (LH) biosynthesis and secretion Studies in the monkey indicate that even arginine vasopressin may play an inhibitory role in controlling gonadotropin secretion. Importantly, GnRH, LH, FSH, and gonadal steroid secretion are developmentally regulated. In the male neonate, for example, a prominent surge of LH and testosterone occurs transiently. Changes in GnRH pulse frequency and amplitude control pituitary gonadotropin subunit gene expression, as well as glycoprotein hormone secretion. Steroid hormones appear to modulate both GnRH and LH and FSH secretion. In short, the hypothalamic-pituitary-gonadal axis is subject to exquisite multilevel regulation.

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

A wide variety of different stressful stimuli will stimulate corticotropin release from the pituitary gland. Two hypothalamic hormones, corticotropin-releasing hormone and arginine vasopressin, have a synergistic action in stimulating corticotropin release. However, the pattern of corticotropin-releasing hormone, arginine vasopressin, and corticotropin secretion varies with the type and chronicity of the stress. Inhibition of corticotropin secretion by cortisol and opioid peptides may also affect the molar ratios of hypothalamic-pituitary-adrenal (HPA) axis hormones. Catecholamines acting through central α1adrenoreceptors are thought to be very important in stimulating the HPA axis. However, peripheral catecholamine concentrations do not necessarily correlate with HPA axis hormones. The relationship between the immune system and the hormones of the HPA axis is a very rapidly advancing area of knowledge in the endocrinology of stress.

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Acromegaly results from growth hormone hypersecretion and is accompanied by deleterious changes in many tissues and organs. Some signs and symptoms of acromegaly respond to growth hormone-lowering therapy, but many are irreversible. Thus, early diagnosis and effective surgical, radiation, and medical therapies are the mainstays of combating this debilitating disease. Over the past several decades, the reestablishment of the transsphenoidal approach to pituitary surgery, the development of magnetic resonance imaging technology, refinements in the delivery of radiotherapy to pituitary tumors, and the development of long-acting somatostatin analogues have greatly improved our ability to effectively treat acromegaly. Advances in our understanding of hypothalamic-pituitary physiology, tumorigenesis, and tumor biology promise to further improve our ability to diagnose and treat patients with growth hormone-secreting pituitary tumors.

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID

ISSN:1068-3097    

出版商:OVID    

年代:1994

数据来源: OVID