Search Results
Results 201 - 250 of 718
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Fuglei E - - 2000
Svalbard's arctic foxes experience large seasonal variations in light, temperature and food supply throughout the year, which may result in periods of starvation. The aim of this work is to investigate if there are seasonal variations in post-absorptive plasma thyroid hormones (free thyroxin (fT(4)), free triiodothyronine (fT(3)) and reverse triiodothyronine ...
Ryszka F - - 2000
The absorption of glycoprotein hormones, i.e. folitropin and lutropin, whose approximate molecular weight is 30,000 D, were estimated for the intranasal administration. The maximal hormone concentrations were observed 30 minutes after their administration. The maximal concentration of folitropin was 32% higher than the maximal concentration of lutropin. Bioavailability level for ...
Elias A N - - 2000
Transcendental meditation (TM) is a stylized form of physical and mental relaxation which is associated with changes in the secretion and release of several pituitary hormones. The hormonal changes induced by TM mimic the effects of the inhibitory neurotransmitter gamma aminobutyric acid (GABA). It is hypothesized that TM produces changes ...
Gómez-Cadenas A - - 2000
The hormonal signals controlling fruitlet abscission induced by sugar shortage in citrus were identified in Satsuma mandarin, Citrus unshiu (Mak.) Marc, cv. Clausellina and cv. Okitsu. Sugar supply, hormonal responses and fruitlet abscission were manipulated through full, partial or selective leaf removals at anthesis and thereafter. In developing fruitlets, defoliations ...
Mitsuma T - - 2000
OBJECTIVE: To develop radioimmunoassay for hypocretin-2 (Hcrt-2). And search for its presence in certain rat tissues. METHODS: Anti-Hcrt-2 serum has been raised in New Zealand white rabbits immunized with a conjugate of synthetic Hcrt-2 with bovine serum albumin. Radioiodination of Hcrt-2 was performed by chloramine T method, followed by purification ...
Lovegrove A - - 2000
The plant hormones gibberellin and abscisic acid regulate gene expression, secretion and cell death in aleurone. The emerging picture is of gibberellin perception at the plasma membrane whereas abscisic acid acts at both the plasma membrane and in the cytoplasm - although gibberellin and abscisic acid receptors have yet to ...
Peters E M - - 2000
Recently, it has been shown that alpha-melanocyte stimulating hormone can directly activate tyrosinase by removing the allosteric regulator 6(R)-L-erythro 5,6,7,8 tetrahydrobiopterin resulting in a stable alpha-melanocyte stimulating hormone/6(R)-L-erythro 5,6,7,8 tetrahydrobiopterin complex. As melanin production occurs in the melanosome, a specific organelle of the melanocyte, it seemed important to investigate whether ...
Karanth S - - 2000
Because ascorbic acid (AA) is concentrated in synaptic vesicles containing glutamic acid, we hypothesized that AA might act as a neurotransmitter. Because AA is an antioxidant, it might therefore inhibit nitric oxidergic (NOergic) activation of luteinizing hormone-releasing hormone (LH-RH) release from medial basal hypothalamic explants by chemically reducing NO. Cell ...
Ismail S M. - - 2000
In the last larval instar of Lepidoptera, ecdysteroid in the absence of juvenile hormone (JH) is believed to cause the shift from larval to pupal development. In Manduca sexta, tissues such as the Verson's gland and crochet epidermis become pupally committed before the earliest pulse of ecdysteroid that occurs on ...
Bhathena S J - - 2000
Significant interactions exist between fatty acids and the endocrine system. Hormones affect the metabolism of fatty acids and the fatty acid composition of tissue lipids. The principal hormones involved in lipid metabolism are insulin, glucagon, catecholamines, cortisol and growth hormone. The concentrations of these hormones are altered in chronic degenerative ...
Peyush P - - 2000
The olive flounder (family Paralichthidae; Paralichthys olivaceus) growth hormone (ofGH) appears to be the most derived among known growth hormones, with the deletion of 14 consecutive amino acids in the carboxy-terminal region. To ascertain if this deletion is common to all flounders, growth hormone complementary DNA of the barfin flounder ...
Minich W B - - 2000
We describe a new method for the detection of different types of pathological autoantibodies against TSH receptor (TSHR) in Graves' patients sera by luminescent immunoprecipitation analysis. For this purpose three different chimeras composed of human TSHR and rat luteotropin/choriogonadotropin receptor (LH-CGR) were constructed, as was described previously (Tahara K, Ishikawa ...
Mitsuma T - - 2000
A radioimmunoassay for orexin A has been developed. Anti-orexin A antiserum was raised in New Zealand white rabbits immunized with a conjugate of synthetic orexin A with bovine serum albumin. This antibody did not crossreact with orexin B, hypothalamic hormones, pituitary hormones, neuropeptides or gut hormones. Radioiodination of orexin A ...
Hofmanová J - - 2000
Carcinogenesis is associated with various epigenetic mechanisms, which can alter intra- and intercellular communication and gene expression and thus affect cytokinetics, i.e. regulation of cell proliferation, differentiation, and apoptosis. These processes lead to a loss of homeostatic control. In addition to "classical" epigenetic events such as DNA methylation and histone ...
Martínez-Madrid M C - - 1999
Hormonal metabolism associated with fruit ripening in two cantaloupe muskmelon cultivars, Talma and Manta, has been studied. The ethylene crisis began on day 33 after fruit set, reaching the maximum values of internal ethylene concentration and ethylene production rate on day 35 after fruit set. This was the optimum moment ...
Vivian-Smith A - - 1999
In Arabidopsis, seedless silique development or parthenocarpy can be induced by the application of various plant growth regulators (PGRs) to unfertilized pistils. Ecotype-specific responses were observed in the Arabidopsis ecotypes Columbia and Landsberg relative to the type of PGR and level applied. The parthenocarpic response was greatest in ecotype Landsberg, ...
Yding Andersen C - - 1999
The ability of different isoforms of follicle stimulating hormone (FSH) to induce the resumption of meiosis in cultured mouse oocytes was evaluated. Oocytes were cultured in the presence of hypoxanthine to prevent spontaneous resumption of meiosis. Using serial dilutions of the isoform fractions representing less acidic isoforms (pI 6. 43-5.69), ...
Sithigorngul W - - 1999
Isolation of the crustacean hyperglycemic hormone (CHH) from the eyestalk of the giant freshwater prawn Macrobrachium rosenbergii was performed using 5,000 ground eye-stalks extracted in methanol-acetic acid-water (90:1:9). After the extract was partially purified using C18 cartridges, it was further purified by eight steps of RP-HPLC using four kinds of ...
Küllertz G - - 1999
Using proembryonic masses (PEMs) of Digitalis lanata Erh., it was demonstrated that cold, hormonal or osmotic stress, which increased freezing tolerance during cryopreservation, induced an increasing level of two peptidyl-prolyl-cis/transisomerases (PPIases). The difference in pI (9.2 +/- 0.2 and 9.5 +/- 0.2, +/- SD; n = 3) allowed the separation ...
Bhatia K S - - 1999
The effect of enhancer(s) (e.g. ethanol (EtOH), 5% linolenic acid/EtOH, and 5% limonene/EtOH) and iontophoresis was investigated on the in vitro percutaneous absorption of luteinizing hormone releasing hormone (LHRH) and ultrastructure of human epidermis by transmission electron microscopy (TEM). 5% linolenic acid/EtOH or 5% limonene/EtOH significantly enhanced (P<0.05) the passive ...
Szponarski W - - 1999
Plasma membrane proteins from Arabidopsis thaliana leaves were reconstituted into proteoliposomes and a K+ diffusion potential was generated. The resulting ionic fluxes, determined in the presence of the plant hormone auxin (indole-3 acetic acid), showed an additional electrogenic and saturable component, with a K(M) of 6 microM. This flux was ...
Marklová E - - 1999
In addition to the main catabolic routes of tryptophan (Trp), there exist minor and less thoroughly investigated pathways; one of these leads to indolylacrylic acid (IAcrA). IAcrA is a plant growth hormone, whereas its biological role in animals is still obscure, as is the way and site where it is ...
Jezek P - - 1998
The mammalian uncoupling protein (UCP-1) from the gene family of mitochondrial carriers is a dimer of identical 33 kDa subunits, each containing six membrane-spanning alpha-helices. Its expression, restricted to brown fat, occurs upon birth, cold acclimation and overfeeding. UCP-1 dissipates redox energy and thereby provides heat to the animal. Two ...
Busk P K - - 1998
The phytohormone abscisic acid is probably present in all higher plants. This hormone is necessary for regulation of several events during seed development and for the response to environmental stresses such as desiccation, salt and cold. An important part of the physiological response to abscisic acid is achieved through gene ...
Miller D B - - 1998
The reproductive properties of estrogen are well established, but it is now evident that this steroid hormone has substantial modulatory capabilities in nonreproductive systems. For example, estrogen may be neuroprotective as Alzheimer's disease progresses more slowly in women receiving hormone replacement therapy, and Parkinson's disease affects more men than women. ...
Uchida Keikichi - - 1998
Infusion of 20-hydroxyecdysone into the hemocoel of unfed decapitated female Culex pipiens pallens mosquitoes, at a very low rate of 500-2000pg per day, often stimulated oögenesis of this species, when the hormone was infused together with amino acids. The hormone alone or amino acids alone showed no such stimulatory effect. ...
Ganem L G - - 1998
Phenobarbital (PB)-mediated induction of five forms of cytochrome P450 (CYP2B1, CYP2B2, CYP3A1, CYP2A1, and CYP2C6) and epoxide hydrolase is highly suppressed, at the transcriptional level, in Wistar Furth (WF) relative to Fischer 344 (F344) female rats. Either hypophysectomy or thyroid hormone depletion by methimazole largely reverses the suppression in WF ...
Bhatia K S - - 1998
The effect of chemical penetration enhancers (e.g., fatty acids) in combination with iontophoresis was examined on the in vitro permeability of luteinizing hormone releasing hormone (LHRH) through porcine skin. Porcine epidermis was pretreated with either ethanol (EtOH) or 10% fatty acid/EtOH. The permeability coefficient of LHRH was significantly (p < ...
Matthys L A - - 1998
Unsaturated long chain fatty acids modulate hormone secretion from a variety of endocrine glands, including the adrenal cortex. Oleic acid and linoleic acid have been shown to stimulate production of glucocorticoids in the absence of adrenocorticotropic hormone, but at a high concentration appeared to inhibit the action of this hormone. ...
Singh V K - - 1998
Splenopentin (SP-5, Arg-Lys-Glu-Val-Tyr) and thymopentin (TP-5, Arg-Lys-Asp-Val-Tyr) are synthetic immunomodulating peptides corresponding to the region 32-34 of a splenic product called splenin (SP) and the thymic hormone thymopoietin (TP), respectively. TP was originally isolated as a 5-kDa (49-amino acids) protein from bovine thymus while studying effects of the thymic extracts ...
Yehuda S - - 1998
The role of fatty acids (FA) as a mediator and modulator of central nervous system activity in general, and peptides in particular, is only recently becoming understood. This paper reviews numerous findings concerned with the activity of fatty acids, particularly with their interaction with diverse neurochemical systems and their consequences ...
Ismail S M - - 1998
In the tobacco hornworm (Manduca sexta), vitellogenin (Vg), the major yolk protein precursor, and its mRNA are first detectable in the prepupal stage; and production of both can be enhanced by methoprene, a juvenile hormone (JH) analog. Competence to respond to methoprene is acquired after ecdysteroid-initiated commitment for metamorphosis. Here ...
Kirby D A - - 1998
Novel thyrotropin-releasing hormone (TRH, pGlu-His-Pro-NH2) analogs, made by solid phase, were derived from the general scaffold pGlu-(D/L)Agl(X)-Pro-NH2 where Agl = aminoglycine. Analogs ranged from X being a proton to an acylating agent derived from substituted (aromatic heterocyclic rings) formic or acetic acids or an aminotriazolyl moiety (3'-amino-1H-1',2',4'-triazolyl) built on N(alpha) ...
Sul H S - - 1998
The activities of critical enzymes in fatty acid and triacylglycerol biosynthesis are tightly controlled by different nutritional, hormonal, and developmental conditions. Feeding previously fasted animals high-carbohydrate, low-fat diets causes a dramatic induction of enzymes-such as fatty acid synthase (FAS) and mitochondrial glycerol-3-phosphate acyltransferase (GPAT)-involved in fatty acid and triacylglycerol synthesis. ...
Busk P K - - 1997
The plant hormone abscisic acid and the transcriptional activator VIVIPAROUS1 have a synergistic effect on transcription during embryo development. An abscisic acid-responsive element (ABRE) mediates induction by abscisic acid and VIVIPAROUS1, but the mechanism involved has not been determined. In this study, we explore the interaction between abscisic acid and ...
Welbourne T C - - 1997
Substrate fluxes in response to growth hormone administration depend on both the calorie as well as acid-base balance. Growth hormone's acidogenic action as a consequence of promoting fatty acid utilization yields protons required for driving hepatic glutamate efflux; effective uncoupling of nitrogenous precursors from ureagenesis and recycling as glutamate bound ...
Boatman D E - - 1997
Spermatozoa and oocytes are separately formed in highly specialized biological compartments (testes and epididymis, ovarian follicle), then deposited communally in the oviduct in an environment designed to facilitate their final maturation, promote their union, and nurture the resultant zygotes and early embryos. The mammalian oviduct undergoes hormonally-mediated cyclical modifications that ...
Guéraud F - - 1997
Growth hormone (GH) effects on fatty acid composition and on delta5-, delta6-, delta9-desaturase and palmitic acid elongation activities were studied in male rat hepatic microsomes. Sham-operated and hypophysectomized animals were injected with two different dosages of GH, mimicking either the male or female GH secretion pattern. Half the hypophysectomized animals ...
Khudaverdyan D N - - 1997
We studied the effects of parathyroid hormone 10(-9) M) on the contents of mono-, di-, and triglycerides, total phospholipids, and free arachidonic acid in rat brain cortex synaptosomes using [1-(14)C]arachidonic acid at 2, 5, and 10 sec after addition of the hormone. Our data demonstrated the changes in lipid metabolism ...
D'Uva E L - - 1997
The subcommissural organ (SCO) is a circumventricular organ of glial origin typical of all vertebrates. The SCO releases its secretion into the third ventricle to constitute Reissner's fibre (RF). Reportedly, in reptiles, SCO has cyclic secretory activity related to the reproductive cycle. In this immunocytochemical study we show that, in ...
Sakurai S - - 1997
A simple method was developed to quantify hemolymph juvenile hormone (JH) and JH acid in hemolymph extracts from Bombyx mori with an established radioimmunoassay (RIA) for JH I. When various organic solvent extracts of hemolymph were assayed by RIA, levels of non-specific binding of the labeled ligand in the assay ...
Mitchell A M - - 1997
The effects of cell swelling induced by hyposmotic shock on efflux of hybrid hormones and selected amino acids from human placental tissue were examined. Decreasing the osmolarity of external medium from 290 to 140 mOsm/kg stimulated release of taurine, tryptophan and glutamine from placental tissue fragments. The efflux rate constant ...
Meyers C Y - - 1997
Estrogen receptor (ER), a member of the nuclear receptor superfamily, exerts prominent physiological roles in both humans and other species by acting directly as a transcription factor, altering nuclear gene expression. One peculiarity of estrogenic regulation is that it is affected by a wide variety of non-steroidal compounds in addition ...
Santos E A - - 1997
Effects of the crustacean hyperglycemic hormone on total lipids in the hemolymph of Chasmagnathus granulata and on free fatty acids, phospholipids, and triglycerides in the hemolymph of Carcinus maenas, as well as on their release by Orconectes limosus hepatopancreas in vitro, were investigated. Eyestalk ablation led to a significant decrease ...
Rieck W - - 1997
The amino acid composition of 148 hair samples from three sisters, covering an age-range of 13-238 months, were analysed using high performance liquid chromatography (RP-HPLC). The measured amino acid concentrations of the three donors showed different individual variation with age. The most pronounced alterations were observed in the concentrations of ...
May L G - - 1997
Osteoclasts, isolated from the endosteum of 2.5- to 3-week-old chickens, were treated with acridine orange, a hydrogen ion concentration-sensitive fluorescent dye, in order to monitor changes in acid production. The adenylate cyclase inhibitor, alloxan, blocked parathyroid hormone (PTH)-stimulated acid production. Dibutyryl cyclic adenosine monophosphate, a membrane-permeant form of cyclic adenosine ...
Scholz G H - - 1997
A series of substituted 4-phenyl-1,4-dihydropyridines 2a-m was tested for their inhibitory effects on L-triiodothyronine (L-T3) uptake by human HepG2 hepatoma cells. The most potent compounds were the nitro-substituted derivatives 2,6-dimethyl-4-(4'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-ethyl ester 5-methyl ester (2m) and the well-known calcium antagonists nitrendipine (2k) and nifedipine (2j) with an uptake inhibition ...
Abrams S. R. - - 1997
We report here the synthesis and biological activity of a new persistent abscisic acid (ABA) analog, 8[prime]-methylene ABA. This ABA analog has one additional carbon atom attached through a double bond to the 8[prime]-carbon of the ABA molecule. (+)-8[prime]-Methylene ABA is more active than the natural hormone (+)-ABA in inhibiting ...
Biolo G - - 1997
We have investigated the effects of 24 h human recombinant growth hormone (hGH) administration on leg muscle glutamine exchange and protein kinetics in severely traumatized patients. Muscle amino acid exchange and protein balance were evaluated using the leg arteriovenous balance technique, whereas changes in skeletal muscle free amino acid concentrations ...
Arrese E L - - 1997
The pathway for the adipokinetic hormone-stimulated synthesis of sn-1,2-diacylglycerols in the adult Manduca sexta fat body was studied. Adult fat body lipids were labeled by feeding 5th instar larvae either with [9,10(n)-3H]oleic acid or [1(3)-3H] glycerol and after 32 days insects at the adult stage were used. This long-term prelabeling ...
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