Abstract:
:To test the hypothesis that the pubertal increase in luteinizing hormone-releasing hormone (LHRH) release is withheld by a dominant inhibitory neuronal system, the role of gamma-aminobutyric acid (GABA), a known inhibitory neurotransmitter, in the control of LHRH release was examined in conscious female monkeys at the prepubertal and pubertal stages using a push-pull perfusion method. GABA, bicuculline (a GABAA receptor blocker), and 2-hydroxysaclofen (a GABAB receptor blocker) were directly infused into the stalk-median eminence while perfusates were collected for LHRH determination. Bicuculline, but not saclofen, induced a large and prompt increase in LHRH release in prepubertal monkeys, whereas it stimulated LHRH release slightly in pubertal monkeys. In contrast, GABA suppressed LHRH release in pubertal, but not prepubertal, monkeys. These differential effects of GABA and the GABA antagonist on LHRH release in the two developmental stages were due to an age factor rather than to the steroid hormonal background. Moreover, GABA release in the stalk-median eminence of prepubertal monkeys was much higher than that in pubertal monkeys. Thus, the results suggest that in the prepubertal period there is a powerful GABA inhibition of the LHRH neurosecretory system: infusions of GABAA, but not GABAB, antagonists stimulate LHRH release by removal of the endogenous GABA inhibition, whereas exogenous GABA is ineffective because of high endogenous GABA levels. The decrease of this tonic inhibition may be a key factor for the onset of puberty in non-human primates.
journal_name
Proc Natl Acad Sci U S Aauthors
Mitsushima D,Hei DL,Terasawa Edoi
10.1073/pnas.91.1.395subject
Has Abstractpub_date
1994-01-04 00:00:00pages
395-9issue
1eissn
0027-8424issn
1091-6490journal_volume
91pub_type
杂志文章abstract::CBP is a transcriptional coactivator required by many transcription factors for transactivation. Rubinstein-Taybi syndrome, which is an autosomal dominant syndrome characterized by abnormal pattern formation, has been shown to be associated with mutations in the Cbp gene. Furthermore, Drosophila CBP is required in hed...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.19.10215
更新日期:1997-09-16 00:00:00
abstract::Embryonic stem cells can be induced in vitro, by coculture with the stromal line RP.0.10 and a mixture of interleukins 3, 6, and 7, to differentiate into T (Joro75+) and B (B-220+) lymphocyte progenitors and other (Thy-1+, PgP-1+, c-kit+, Joro75-, B-220-, F4/80-, Mac-1-) hemopoietic precursors. The progeny of in vitro...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.19.9171
更新日期:1992-10-01 00:00:00
abstract::RNA polymerase pausing represents an important mechanism of transcriptional regulation. In this study, we use a single-molecule transcription assay to investigate the effect of template base-pair composition on pausing by RNA polymerase II and the evolutionarily distinct mitochondrial polymerase Rpo41. For both enzyme...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1205063109
更新日期:2012-06-05 00:00:00
abstract::Two high molecular weight heat shock proteins, HSP90 (Mr, 90,000) and HSP100 (Mr, 100,000), were separately purified from extracts of cultured cells of a mouse lymphoma cell line, L5178Y. Both of the HSPs exist in homodimeric form under physiological conditions. Their physicochemical properties are quite similar to ea...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.21.8054
更新日期:1986-11-01 00:00:00
abstract::The oligodendrocyte (Od), a glial cell that produces myelin in the central nervous system, may be a target for autoreactive T cells in autoimmune demyelinating processes, although not expressing major histocompatibility complex (MHC) products. To analyze Od-T-cell interactions, we selected from normal SJL/J mouse sple...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.8.2824
更新日期:1989-04-01 00:00:00
abstract::Social insects are promising new models in aging research. Within single colonies, longevity differences of several magnitudes exist that can be found elsewhere only between different species. Reproducing queens (and, in termites, also kings) can live for several decades, whereas sterile workers often have a lifespan ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1804046115
更新日期:2018-05-22 00:00:00
abstract::Protective immunity against human schistosome infection develops slowly, for reasons that are not yet fully understood. For many decades, researchers have attempted to infer properties of the immune response from epidemiological studies, with mathematical models frequently being used to bridge the gap between immunolo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1121051109
更新日期:2012-08-14 00:00:00
abstract::Tolerance and resistance provide hosts with two distinct defense strategies against parasitism. In resistance the hosts "fight" the parasite directly, whereas in tolerance the hosts fight the disease by ameliorating the damage that infection causes. There is increasing recognition that the two mechanisms may exhibit v...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0809558105
更新日期:2008-12-30 00:00:00
abstract::Total chemical synthesis was used to prepare the mirror image (D-protein) form of the angiogenic protein vascular endothelial growth factor (VEGF-A). Phage display against D-VEGF-A was used to screen designed libraries based on a unique small protein scaffold in order to identify a high affinity ligand. Chemically syn...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1210483109
更新日期:2012-09-11 00:00:00
abstract::Distribution studies disclosed that all major cerebral arteries and cortical arterioles of the cat were invested with fine varicose nerve fibers that contained calcitonin gene-related peptide (CGRP)-like immunoreactivity; the trigeminal ganglia likewise contained CGRP immunoreactivity. Sequential immunostaining with a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.15.5731
更新日期:1986-08-01 00:00:00
abstract::In autotrophically grown Chlorella cells, glucose induces a hexose transport system but, at the same time, the synthesis of two amino acid transport systems is also induced. Thus, the rates of uptake of glycine, L-alanine, L-proline, and L-serine, all of which compete with each other for entry into the cells, increase...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.78.6.3591
更新日期:1981-06-01 00:00:00
abstract::Phase separation of multivalent protein and RNA molecules underlies the biogenesis of biomolecular condensates such as membraneless organelles. In vivo, these condensates encompass hundreds of distinct types of molecules that typically organize into multilayered structures supporting the differential partitioning of m...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1821038116
更新日期:2019-04-16 00:00:00
abstract::NMDA receptors are excitatory channels with critical functions in the physiology of central synapses. Their activation reaction proceeds as a series of kinetically distinguishable, reversible steps, whose structural bases are currently under investigation. Very likely, the earliest steps include glutamate binding to g...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2007511118
更新日期:2021-01-12 00:00:00
abstract::Whether and how human populations exposed to the agricultural revolution are still affected by Darwinian selection remains controversial among social scientists, biologists, and the general public. Although methods of studying selection in natural populations are well established, our understanding of selection in hum...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.1118174109
更新日期:2012-05-22 00:00:00
abstract::Systemic anthrax, caused by inhalation or ingestion of Bacillus anthracis spores, is characterized by rapid microbial growth stages that require iron. Tightly bound and highly regulated in a mammalian host, iron is scarce during an infection. To scavenge iron from its environment, B. anthracis synthesizes by independe...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0607055103
更新日期:2006-12-05 00:00:00
abstract::The motion and mixing of granular media are observed in several contexts in nature, often displaying striking similarities to liquids. Granular dynamics occur in geological phenomena and also enable technologies ranging from pharmaceuticals production to carbon capture. Here, we report the discovery of a family of gra...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1820820116
更新日期:2019-05-07 00:00:00
abstract::We developed a method for rapidly generating thermostable enzyme variants. Our strategy is to introduce the gene coding for a given enzyme from a mesophilic organism into a thermophile, Bacillus stearothermophilus. Variants that retain the enzymatic activity at the higher growth temperatures of the thermophile are the...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.3.576
更新日期:1986-02-01 00:00:00
abstract::As chips further shrink toward smaller scales, fabrication processes based on the self-assembly of individual particles into patterns or structures are often sought. One of the most popular techniques for two-dimensional assembly (self-assembled monolayers) is based on capillary forces acting on particles placed at a ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0712392105
更新日期:2008-03-11 00:00:00
abstract::γ-Secretase is an intramembrane-cleaving protease responsible for the generation of amyloid-β (Aβ) peptides. Recently, a series of compounds called γ-secretase modulators (GSMs) has been shown to decrease the levels of long toxic Aβ species (i.e., Aβ42), with a concomitant elevation of the production of shorter Aβ spe...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1402171111
更新日期:2014-07-22 00:00:00
abstract::The Tsc2 gene, which is mutationally inactivated in the germ line of some families with tuberous sclerosis, encodes a large, membrane-associated GTPase activating protein (GAP) designated tuberin. Studies of the Eker rat model of hereditary cancer strongly support the role of Tsc2 as a tumor suppressor gene. In this s...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.17.9154
更新日期:1996-08-20 00:00:00
abstract::The candidate phylum TM7 is globally distributed and often associated with human inflammatory mucosal diseases. Despite its prevalence, the TM7 phylum remains recalcitrant to cultivation, making it one of the most enigmatic phyla known. In this study, we cultivated a TM7 phylotype (TM7x) from the human oral cavity. Th...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1419038112
更新日期:2015-01-06 00:00:00
abstract::The molecular basis for the absence of anthocyanins and proanthocyanidins in four independent sodium azide-induced ant18 mutants of barley was examined by sequencing the gene encoding dihydroflavonol 4-reductase in these mutants. Sodium azide generated 21 base substitutions, which corresponds to 0.17% of the 12,704 nu...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.17.8043
更新日期:1993-09-01 00:00:00
abstract::By the use of a rat kidney cell line infected with a temperature-sensitive Rous sarcoma virus, we have shown that, at permissive temperatures where the cells are transformed, concanavalin A induces a clustering of its cell membrane receptors into patches, and the intracellular smooth muscle myosin-like protein is in a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.73.10.3603
更新日期:1976-10-01 00:00:00
abstract::3H-Labeled complementary DNA specific for the envelope glycoprotein (env) gene of avian leukosis-sarcoma viruses was isolated by selective nucleic acid hybridization techniques, and used to analyze the expression of the endogenous provirus. The endogenous provirus in certain cell types termed chicken helper factor pos...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.73.7.2259
更新日期:1976-07-01 00:00:00
abstract::Antigen receptor variable region exons are assembled during lymphocyte development from variable (V), diversity (D), and joining (J) gene segments. Each germ-line gene segment is flanked by recombination signal sequences (RSs). Recombination-activating gene endonuclease initiates V(D)J recombination by cleaving a pair...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1019293108
更新日期:2011-02-01 00:00:00
abstract::Antigen.antibody complexes (Ag.Ab) prepared from (125)I-labeled bovine serum albumin and guinea pig anti-albumin were incubated at 37 degrees C for 30 min with normal human serum diluted optimally for binding (1:16) and then with autologous erythrocytes (RBC). After washing, RBC-bearing antigen.antibody.complement com...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.16.5047
更新日期:1982-08-01 00:00:00
abstract::We address the stability of multicharged finite systems driven by Coulomb forces beyond the Rayleigh instability limit. Our exploration of the nuclear dynamics of heavily charged Morse clusters enabled us to vary the range of the pair potential and of the fissibility parameter, which results in distinct fragmentation ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.142253999
更新日期:2002-07-09 00:00:00
abstract::Fluoxetine (Prozac) inhibited the membrane currents elicited by serotonin (5-hydroxytryptamine; 5HT) in Xenopus oocytes expressing either cloned 5HT2C receptors or 5HT receptors encoded by rat cortex mRNA. Responses of 5HT2C receptors, elicited by nM concentrations of 5HT, were rapidly and reversibly blocked by microm...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.5.2036
更新日期:1997-03-04 00:00:00
abstract::Cyclophilins are a family of ubiquitous proteins that are the intracellular target of the immunosuppressant drug cyclosporin A. Although cyclophilins catalyze peptidylprolyl cis-trans isomerization in vitro, it has remained open whether they also perform this function in vivo. Here we show that Cpr3p, a cyclophilin in...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.14.6319
更新日期:1995-07-03 00:00:00
abstract::The hereditary hearing-vision loss disease Usher syndrome (USH) is caused by defects in several proteins, most of which form an integrated protein network called Usher interactome. Harmonin/Ush1C is a master scaffold in the assembly of the Usher protein complexes, because harmonin is known to bind to every protein in ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0901819106
更新日期:2009-04-07 00:00:00