Crustacean hyperglycemic hormone (CHH) and vitellogenesis-inhibiting
hormone (VIH), produced by the X organ–sinus gland neurosecretory com-plex, belong to a peptide group referred to as the CHH family, which is
widely distributed in arthropods. In this study, genetic variants and post-translationally modified isoforms of CHH and VIH were characterized in
the European lobster Homarus gammarus.
One of the important peptide hormones that control reproduction in crus-taceans is gonad-inhibiting hormone (GIH). GIH is known to modulate
gonad maturation by inhibiting synthesis of vitellogenin (Vg), the precursor
of yolk proteins. In this study, a cDNA encoding a GIH (Pem-GIH) from
the eyestalk of Penaeus monodonwas cloned using RT-PCR and RACE
The currently accepted model of moult control in crusta-ceans relies entirely on the hypothesis that moult-inhibiting
hormone (MIH) and crustacean hyperglycaemic hormone
(CHH) repress ecdysteroid synthesis of the target tissue
(Y-organ) only during intermoult, and that changes in syn-thesis and/or release of these neurohormones are central to
release of STH (and also other peptide hormones including insulin, glucagon, and gastrin). PRH: prolactin-RH remains to be characterized or established. Both TRH and vasoactive intestinal peptide (VIP) are implicated. PRIH inhibits the release of prolactin and could be identical with dopamine. Hypothalamic releasing hormones are mostly administered (parenterally) for diagnostic reasons to test AH function. Therapeutic control of AH cells. GnRH is used in hypothalamic infertility in women to stimulate FSH and LH secretion and to induce ovulation.
The poorly known mechanism of inhibition of cholinesterases by inorganic
mercury (HgCl2) has been studied with a view to using these enzymes as
biomarkers or as biological components of biosensors to survey polluted
areas. The inhibition of a variety of cholinesterases by HgCl2
was investi-gated by kinetic studies, X-ray crystallography, and dynamic light scatter-ing.
Retinoids are potent immune modulators that inhibit Fas ligand (FasL) expression and thereby repress the activationinduced apoptosis of immature thymocytes and T-cell hybridomas. In this study, we demonstrate that all-transretinoic acid (all-trans-RA) directly represses the transcriptional activity of the nuclear factors of activated T-cells (NFAT), which is an important transactivator of the FasL promoter.
Although the crustacean crustacean hyperglycemic hormone⁄molt-inhibi-ting hormone⁄gonad-inhibiting hormone neuropeptides have been studied
extensively in the last two decades and several neuropeptides from the
shrimpMetapenaeus ensishave been cloned, the functions of most of these
neuropeptides remained putative.
Arachidonic acid and its lypoxygenated metabolites play a fundamental
role in the hormonal regulation of steroidogenesis. Reduction in the expres-sion of the mitochondrial acyl-CoA thioesterase (MTE-I) by antisense or
small interfering RNA (siRNA) and of the arachidonic acid-preferring
acyl-CoA synthetase (ACS4) by siRNA produced a marked reduction in
steroid output of cAMP-stimulated Leydig cells.
Activation of a temperature-sensitive formof p53 inmurine
erythroleukaemia cells results in a rapid impairment of
protein synthesis that precedes inhibitionof cell proliferation
and loss of cell viability by several hours. The inhibition of
translation is associated with specific cleavages of polypep-tide chain initiation factors eIF4GI and eIF4B, a pheno-menon previously observed in cells induced to undergo
apoptosis in response to other stimuli.
Gonadotropin-releasing hormone antagonists (GnRH-nt) available for clinical use are GnRH molecules with amino acid modiﬁcations in positions 1, 2, 3, 6, and 10. They are not associated with the histaminic-release effects of previous compounds (1). These compounds immediately block GnRH receptor in a competitive fashion (2). They decrease the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion within a period of eight hours. Inhibition of LH secretion is more important than FSH.
This article reports an inhibitory effect of rapamycin on the lipopolysac-charide (LPS)-induced expression of both inducible nitric oxide synthase
(iNOS) and granulocyte-colony stimulating factor (G-CSF) in macrophages
and its underlying mechanism.
This textbook is primarily intended to provide undergraduate students of pharmacy with a clear and concise
account of basic endocrine function and dysfunction, at a level sufficient to meet the requirements of first- or
second year qualifying examinations. It is not intended to replace standard texts, but merely to serve as an
accompaniment and convenient revision guide.
The reactive center loop (RCL) of serpins plays an essential role in the
inhibition mechanism acting as a substrate for their target proteases. Chan-ges within the RCL sequence modulate the specificity and reactivity of the
serpin molecule. Recently, we reported the construction of a1-antichymo-
Dehydroepiandrosterone (DHEA), a steroid hormone, modified the proli-feration of human umbilical vein endothelial cells in a dose-dependent
manner. Its inactive sulfate ester (DHEA-S) and two of its metabolites –
estradiol and testosterone – had no inhibitory effect at physiological
concentrations. Antiproliferation was associated with arrest in the G1
phase of the cell cycle, but not with cell death, as evaluated by cleavage
of poly(ADP-ribose) polymerase and exposure of phosphatidylserine. ...
Several peptides that specifically bind the HIV-1 integrase (IN) and either
inhibit or stimulate its enzymatic activity were developed in our laborato-ries. Kinetic studies using 3¢-end processing and strand-transfer assays were
performed to study the mode of action of these peptides.
Ouabain, a sodiumpump (Na
-ATPase) inhibitor, has
been shown to act as a hormone and is possibly involved in
the pathogenesis of hypertension. The mechanismby which
ouabain may act was investigated using primary cultures of
human umbilical artery endothelial cells (HUAECs), which
are known to express and release the vasoconstrictive hor-mone endothelin (ET-1). Fiveminutes after application, low
concentrations of ouabain induced Ca
stimulated ET-1 release from endothelial cells into the
Malonyl-CoA, a potent inhibitor of carnitine pamitoyl
transferase-I (CPT-I), plays a pivotal role in fuel selection in
cardiac muscle. Malonyl-CoA decarboxylase (MCD) cata-lyzes the degradation of malonyl-CoA, removes a potent
allosteric inhibition on CPT-I and thereby increases fatty
acid oxidation in the heart. Although MCDhas several Ser/
Thr phosphorylation sites, whether it is regulated by AMP-activated protein kinase (AMPK) has been controversial.
We therefore overexpressed MCD(Ad.MCD) and consti-tutively active AMPK (Ad.
The IAL-PID2 cells derived from imaginal wing discs of the
last larval instar of Plodia interpunctellawere responsive to
20-hydroxyecdysone (20E). These imaginal cells respond to
20E by proliferative arrest followed by a morphological
differentiation. These 20E-induced late responses were
inhibited in presence of juvenile hormone (JH II). From
these imaginal wing cells, we have cloned a cDNA sequence
encoding aP. interpunctellaecdysone receptor-B1 isoform
A naturally occurring variant of the human androgen receptor (AR) named
AR45 has been identified. It lacks the entire region encoded by exon 1 of the
ARgene and is composed of the AR DNA-binding domain, hinge region
and ligand-binding domain, preceded by a novel seven amino-acid long
N-terminal extension. A survey of human tissues revealed that AR45 was
expressed mainly in heart and skeletal muscle. In cotransfection experiments,
AR45 inhibited AR function, an effect necessitating intact DNA- and
ligand-binding properties. ...
generation is a limiting step in thyroid hormone bio-synthesis. Biochemical studies have confirmed that H2O2is
generated by a thyroid Ca
Decreased H2O2 availability may be another mechanism
of inhibition of thyroperoxidase activity produced by thio-ureylene compounds, as propylthiouracil (PTU) and
methimazole (MMI) are antioxidant agents. Therefore, we
analyzed whether PTU or MMI could scavenge H2O2or
inhibit thyroidNADPHoxidase activityin vitro.