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1.
Met5-enkephalin amide, D-Ala2-Met5-enkephalin amide, D-Ala2-Leu5-enkephalin amide, morphine sulfate and naloxone hydrochloride were examined for their effects on growth hormone and prolactin release and . Subcutaneous injection of D-Ala2-Met5 enkephalin amidea, D-Ala2-Leu5 enkephalin amideb and morphine sulfate, but not Met5-enkephalin and amidec, resulted in significant elevations in the serum growth hormone and prolactin of immature female rats. Naloxone blocked the hormone-stimulatory effect of the opioid receptor agonists and when administered alone significantly reduced serum growth hormone and prolactin concentrations. None of the drugs demonstrated a direct action on anterior pituitary tissue growth hormone or prolactin release . 相似文献
2.
L.G. Frigeri Greg Robel Nowell Stebbing 《Biochemical and biophysical research communications》1982,104(3):1041-1046
Bacteria-derived human growth hormone (hGH) shows little lipolytic activity in adipose tissue from fed rats. In adipose tissue from fasted rats no lipolytic activity is observed. However, bacteria-derived hGH increased serum free fatty acids after intraperitoneal administration to hypophysectomized rats to the same extent as purified pituitary hGH. The dose response of the bacteria-derived hGH tested for insulin-like activity was very similar to the pituitary extracted material. Thus bacteria-derived hGH behaves in a manner indistinguishable from highly purified preparations of pituitary hGH. 相似文献
3.
The antiinflammatory activity of a homologous series of α-alkyl substituted [4-(1-oxo-2-iso-indolinyl)-phenyl]-acetic acid has been assayed by some and tests.These compounds were shown to be particularly active in inhibiting prostaglandin biosynthesis from bovine seminal vesicles, and their potency was seen to increase as the size of the substituents in the side chain increased.The antiinflammatory activity is not correlated with inhibition of PG-synthetase. Discussion of the data takes into account the plasma protein binding and pharmacokinetics of these compounds. 相似文献
4.
A protein containing fraction that will bind 1,25-dihydroxyvitamin D3 both and has been solubilized from the nuclear-debris fraction of rat intestinal mucosa and purified 15-fold. 相似文献
5.
A particulate factor of rat liver is described which interconverts three forms of rat liver cytosolic tyrosine aminotransferase with no alteration of enzyme activity. The factor appears to be a heat- and pH-sensitive lysosomal protein. The interconversion process is stimulated by 2.5 mM MgCl2 and 2.5 mM ATP. Asparate aminotransferase multiple forms are also susceptible to interconversion by the lysosomal factor. The properties of the factor explain several anomalous effects of manipulation on the tyrosine aminotransferase forms which have been reported in the literature and implicate the form interconversion in the degradation of tyrosine aminotransferase. 相似文献
6.
William B. Wehrenberg Nicholas Ling Paul Brazeau Fred Esch Peter Böhlen Andrew Baird Shao Ying Roger Guillemin 《Biochemical and biophysical research communications》1982,109(2):382-387
The synthetic replicate of a 44 amino acid peptide isolated from a human pancreatic tumor which had caused acromegaly possesses high specific activity to release growth hormone (GH) in anesthetized male rats. The GH secretion induced by this peptide is dose-dependent from 50 ng to 1 μg, with plasma GH concentrations increasing more than 10-fold within 5 min of iv administration at the higher doses. Two enzymatic degradation products of the 44 residue peptide were also isolated and consist of the first 37 and 40 amino acids. All three peptides appear to possess similar potency, on a molar basis, , contrary to results. The specificity of these peptides on GH release was shown by their failure to alter plasma concentrations of prolactin (PRL), thyroid-stimulating hormone (TSH), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and corticosterone. Based on these results, the three peptides with serve as powerful tools with which to investigate the mechanisms of GH secretion. 相似文献
7.
The site at which opiate agonists and antagonists act to alter secretion of prolactin, growth hormone and luteinizing hormone as well as the pharmacological specificity of the opiate receptors mediating these effects were examined in rats. Injection of β-endorphin but not a 10 fold higher dose of the non opiate peptide β-endorphin, increased release of prolactin and growth hormone in male rats while inhibiting luteinizing hormone release in ovariectomized, estrogen primed female rats. Prior treatment with naltrexone i.p. blocked these responses. Injection of naltrexone into the hypothalamus lowered prolactin release. In rats with a surgically formed hypothalamic island systemic administration of morphine or naltrexone altered prolactin release in the same manner as was observed in intact animals. In contrast no effects of β-endorphin or naltrexone were observed on the spontaneous secretion of prolactin . In addition β-endorphin did not alter the inhibition of prolactin release produced by apomorphine . The ED50 for stimulation of prolactin release following intraventricular administration of β-endorphin or the synthetic enkephalin analog FK 33-824 was the same, approximately 0.1 ng/rat. However FK 33-824 at 0.2 ng/rat was able to produce much greater analgesia and catatonia than β-endorphin. The metabolism and distribution of β-endorphin was examined but did not account for these differential effects. These results indicate that opiate agonists and antagonists can act at the hypothalamic but not the anterior pituitary level to alter release of prolactin, growth hormone and luteinizing hormone. In addition the data suggest that the opiate receptors mediating release of prolactin may have a different pharmacological specificity from those involved with analgesia and catatonia. 相似文献
8.
G Goldberg T Zarucki-Schulz P Caldwell H Weissbach N Brot 《Biochemical and biophysical research communications》1979,91(4):1453-1461
The DNA dependent synthesis of ribosomal protein L12 and the β subunit of RNA polymerase has been investigated using DNA from a plasmid which contains the genetic information for ribosomal protein L12 and the β subunit of RNA polymerase. This DNA, however, lacks the promoter region and the genetic information for the first 26 amino acids of ribosomal protein L10. It was found that L12 and the β subunit of RNA polymerase are efficiently synthesized from this DNA. These results suggest that L12 and the β subunit of RNA polymerase can be synthesized from a promoter situated within the L10 gene. 相似文献
9.
Electrophoretically homogeneous myeloma light chain mRNA and its translation in vitro 总被引:12,自引:0,他引:12
mRNA coding for the light chain of a myeloma protein has been purified to give one band in acrylamide gel electrophoresis. This pure RNA (S~13.5) could be translated into the light chain in a heterologous cell-free translation system. The light chain synthesized is apparently slightly larger than the light chain secreted by the tumor. 相似文献
10.
11.
Based on the knowledge that dimethyl sulfoxide (DMSO) can induce differentiation and function of several types of immature neoplastic cell lines, we examined the effects of DMSO on the function of normal pituitary cells with high activity and found that it stimulated the synthesis and release of growth hormone and prolactin in the anterior pituitary from lactating mouse. 相似文献
12.
The influence of cycloheximide on amino acid incorporation into protein of standard strain ? + and cytoplasmic mutant ? ? of was determined and . cycloheximide at the concentration which inhibits protein synthesis in ? + strain by over 60% has litle or no effect in mutant ? ? strain. cycloheximide in the range of 0.05 to 0.3 ug/ml of incubation medium inhibits polyphenylalanine synthesis in ? + strain by 50% and in ? ? strain by less than 10%. Similar resistance to this antibiotic are shown in standard strain grown in anaerobic conditions. It has been found that the resistance to cycloheximide is associated with changes in cytoplasmic ribosomes and may depend on the integrity of mitochondrial system. 相似文献
13.
Cytoplasmic free and bound polysomes were isolated from bovine adrenal cortex, and used to program protein synthesis in rat liver cell sap and wheat germ lysate systems. Synthesis of adrenodoxin(Ad) and adrenodoxin reductase(AdR) in the cell-free systems was determined by immunoprecipitation using monospecific antibodies, and the sizes of the products were analyzed by SDS-polyacrylamide gel electrophoresis. Ad was synthesized by both free and bound polysomes as a putative large precursor having molecular weight of approximately 20,000 daltons, which was processed to mature size Ad (MW 12,000 daltons) by incubation with adrenal cortex mitochondria. On the other hand, AdR was synthesized only by free polysomes apparently as the mature size product. 相似文献
14.
S Lavielle N Ling P Brazeau R Benoit T Wasada D Harris R Unger R Guillemin 《Biochemical and biophysical research communications》1979,91(2):614-622
The synthesis by solid-phase methodology of two glycosylated analogs of somatostatin [Glc-Asn5]-SS and [NAcGlc-Asn5]-SS is described. These two analogs have been biologically tested on the secretion of pituitary growth hormone, pancreatic glucagon and insulin. The results show that glycosylation of somatostatin on the Asn5 residue decreases by a hundred fold the inhibition activity on GH release when tested . , since the activity is similar to somatostatin the carbohydrates are probably removed by some enzymatic reaction and thus liberate the full activity of somatostatin. 相似文献
15.
E Shrago 《Life sciences》1978,22(1):1-5
The adenine nucleotide translocase, the transport protein for ADP and ATP, located in the inner mitochondrial membrane is an important site for the regulation of cell metabolism. Inhibition of the adenine nucleotide translocase by long chain fatty acyl CoA esters demonstrated may also occur when the complete oxidation of fatty acids by the myocardium has been compromised during ischemia. Reversal of this biochemical lesion may be of benefit in the preservation of the ischemic myocardium. 相似文献
16.
Johannes D. Veldhuis Patricia A. Klase 《Biochemical and biophysical research communications》1982,104(2):603-610
The divalent-cation ionophores A23187 and ionomycin exert dose-dependent suppressive effects on the stimulatory actions of luteinizing hormone in ovarian cells . Micromolar concentrations of both A23187 and ionomycin can inhibit the production of progesterone and the stimulation of ornithine decarboxylase activity. Inhibitory concentrations of these ionophores deplete total cell content of calcium, and also seem to suppress protein synthesis. 相似文献
17.
Corticosterone alone was not able to stimulate release of luteinizing hormone (LH) from anterior pituitary cells , but corticosterone in combination with luteinizing hormone releasing hormone (LHRH) augmented the release of LH into the culture media. These results may indicate that corticosterone may have the capacity to activate membrane receptors for LHRH in the gonadotrophs. 相似文献
18.
George M. Stancel Judy S. Ireland Venkat R. Mukku Alice K. Robison 《Life sciences》1980,27(12):1111-1117
The pesticide o,p'-DDT stimulates the production of a specific uterine protein, the so-called induced protein or IP, normally associated with an estrogenic response of the uterus. stimulation of IP production is observed 1 hour after the administration of 250 mg/kg of o,p'-DDT to immature rats. stimulation of IP production is observed after a 1 hour incubation of uteri with 100 μM o,p'-DDT. This response is blocked by Actinomycin D. In contrast to o,p'-DDT, which binds to the cytoplasmic estrogen receptor and stimulates IP production, p,p'-DDT which does not bind well to the estrogen receptor does not stimulate IP production . These findings represent the first report of an estrogenic effect of o,p'-DDT in a completely system. 相似文献
19.
Phosphorylation of high mobility group proteins 14 and 17 by nuclear protein kinase NII in rat O6 glioma cells 总被引:1,自引:0,他引:1
J J Harrison R A Jungmann 《Biochemical and biophysical research communications》1982,108(3):1204-1209
High mobility group (HMG) proteins 14 and 17 of rat C6 glioma cells are phosphorylated on both serine and threonine. In HMG 14 about 60% of the total [32P]phosphate was identified as phosphoserine and 40% as phosphothreonine. In HMG 17, there was 88% phosphoserine and 12% phosphothreonine. Glioma cell nuclear protein kinase NII phosphorylates HMG 14 and 17 on serine as well as threonine and the relative percentages of [32P]phosphoamino acid are similar to those seen . Nuclear protein kinase NI and the type I and II cAMP-dependent protein kinases exhibit only minor phosphorylating activity towards HMG 14 and 17. We conclude that nuclear protein kinase NII is responsible for the phosphorylation of HMG 14 and 17 . 相似文献
20.
The intestinal nuclear receptor for lα,25-dihydroxyvitamin D3 has been utilized to determine the ability of vitamin D-active sterols to compete with this hormone at the molecular level. 25-Hydroxyvitamin D3 and lα-hydroxyvitamin D3 must be present in 150 and 450 times the concentration respectively of lα,25-dihydroxyvitamin D3, , to displace the physiologic hormone. These data indicate that: i) superphysiologic levels of 25-hydroxyvitamin D3 may simulate lα,25-dihydroxyvitamin D3 and act directly on isolated target organs and ii) the biologic potency observed for low doses of lα-hydroxyvitamin D3, , is probably the result of 25-hidroxylation of the lα-derivative to form lα,25-dihydroxyvitamin D3. 相似文献