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51.
Alexandra I. M. Breukel Victor M. Wiegant Fernando H. Lopes da Silva Wim E. J. M. Ghijsen 《Journal of neurochemistry》1998,70(1):341-348
Abstract: The role of protein kinase C (PKC) in modulating the release of the octapeptide cholecystokinin (CCK-8) was investigated in rat hippocampal nerve terminals (synaptosomes). The PKC-activating phorbol ester 4β-phorbol 12,13-dibutyrate (β-PDBu) dose dependently (5–5,000 n M ) increased CCK-8 release in a strictly Ca2+ -dependent way. This effect was observed only when synaptosomes were stimulated with the K+ A channel blocker 4-aminopyridine (4-AP; 1 m M ) but not with KCI (10–30 m M ). The PDBu-induced exocytosis of CCK-8 was completely blocked by the two selective PKC inhibitors chelerythrine and calphostin-C and was not mimicked by α-PDBu, an inactive phorbol ester. In addition, an analogue of the endogenous PKC activator diacylglycerol, oleoylacetylglycerol, dose dependently increased CCK-8 exocytosis. β-PDBu (50–100 n M ) also stimulated the 4-AP-evoked Ca2+ -dependent release of the classic transmitter GABA, which co-localizes with CCK-8 in hippocampal interneurons. As a possible physiological trigger for PKC activation, the role of the metabotropic glutamate receptor was investigated. However, the broad receptor agonist (1 S ,3 R )-1-aminocyclopentane-1,3-dicarboxylic acid did not stimulate, but instead inhibited, both the CCK-8 and the GABA exocytosis. In conclusion, presynaptic PKC may stimulate exocytosis of distinct types of colocalizing neurotransmitters via modulation of presynaptic K+ channels in rat hippocampus. 相似文献
52.
Michael G Anderson Richard T Libby Mao Mao Ioan M Cosma Larry A Wilson Richard S Smith Simon WM John 《BMC biology》2006,4(1):20-11
Background
DBA/2J (D2) mice develop an age-related form of glaucoma. Their eyes progressively develop iris pigment dispersion and iris atrophy followed by increased intraocular pressure (IOP) and glaucomatous optic nerve damage. Mutant alleles of the Gpnmb and Tyrp1 genes are necessary for the iris disease, but it is unknown whether alleles of other D2 gene(s) are necessary for the distinct later stages of disease. We initiated a study of congenic strains to further define the genetic requirements and disease mechanisms of the D2 glaucoma. 相似文献53.
54.
In the preceding paper, a method to detect specific DNA sequences with mercurated nucleic acid probes and sulfhydryl-hapten ligands has been described. Due to the instability of the bond between mercury and a negatively charged sulfhydryl-hapten ligand (trinitrophenyl-glutathione), the in situ formed hybrid could not be detected. On basis of model system experiments it was suggested that this mercury-sulfhydryl bond could be stabilized by an extra polar interaction between ligand and nucleic acid. This was achieved by reversing the net charge of the ligand. Such ligands were synthesized by reacting aliphatic diamines to the carboxyl groups of Tnp-glutathione using a water soluble carbodiimide. Gel chromatographic analysis of mercurated polynucleotide-ligand complexes showed that the stability of the mercury-sulfhydryl bond is increased by the reversal of the net charge of the ligand. In situ hybridized mercurated mouse satellite DNA to mouse liver nuclei and mercurated kinetoplast cRNA hybridized to Crithidia fasciculata were immunocytochemically detected after the introduction of these positively charged ligands. The described method is applicable for RNA and DNA probes. It has a sensitivity comparable to other non-autoradiographic methods, is relatively simple to perform and can be carried out with ordinary laboratory chemicals. 相似文献
55.
A non-radioactive in situ hybridization method based on mercurated nucleic acid probes and sulfhydryl-hapten ligands. 总被引:4,自引:3,他引:1 下载免费PDF全文
Mercurated nucleic acid probes can be used for non-radioactive in situ hybridization. The principle of the method is based on the reaction of the mercurated pyrimidine residues of the in situ hybridized probe with the sulfhydryl group of a ligand which contains a hapten. Next, the hapten is immunocytochemically detected. Previous experiments showed that stable coupling of the sulfhydryl ligands could only be obtained when positively charged amino groups are present in the ligand. On basis of this finding, ligands were synthesized containing a sulfhydryl group, two lysyl residues and hapten groups such as trinitrophenyl, fluorescyl and biotinyl. The ligands, free or bound to mercurated nucleic acids, were immunochemically characterized in ELISAs. The method was shown to be specific and sensitive in the detection of target DNA in situ on microscopic preparations and in dot-blot hybridization reactions on nitrocellulose. 相似文献
56.
J. G. J. Bauman J. Wiegant P. Van Duijn N. H. Lubsen P. J. A. Sondermeijer W. Hennig E. Kubli 《Chromosoma》1981,84(1):1-18
Fluorochrome-labeled RNA allows the rapid detection of in situ hybrids without the need for long exposure times as in the autoradiographical hybridisation methods. Resolution is high because of the high resolving power of fluorescence microscopy. The application of a previously reported method for the hybrido-cytochemical detection of DNA sequences to polytene chromosomes of Drosophilia is described. — The specificity and sensitivity of the method are demonstrated by the hybridisation with polytene chromosomes of 1) rhodamine-labeled 5S RNA, to the 5S rRNA sites of D. melanogaster (56F) and D. hydei (23 B), 2) rhodamine-labeled RNA complementary to a plasmid containing histone genes, to the 39DE region of D. melanogaster, 3) rhodamine-labeled D. melanogaster tRNA species (Gly-3 and Arg-2), to their respective loci in D. melanogaster, 4) rhodamine-labeled RNA complementary to the insert of plasmid 232.1 containing part of a D. melanogaster heat shock gene from locus 87 C, to D. hydei heat shock locus 2-32A. In the latter instance it was possible to demonstrate the labeling of a double band which escaped unambiguous detection by autoradiography in the radioactive cytochemical hybridisation procedure because of the low topological resolution of autoradiograms. — The sensitivity of the fluorochrome-labeled RNA method is compared with the radioactive methods which use 3H- or 125I-labeled RNAs. The factors governing the sensitivity and the number of bound fluorochrome molecules to be expected are discussed.Dedicated to Professor W. Beermann in honour of his 60th birthday 相似文献
57.
J.A.D.M. Tonnaer J. Verhoef V.M. Wiegant W. de Jong 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1980,183(3):303-309
A high-performance chromatographic technique for the separation of angiotensins and some related peptides is described. Complete separation of angiotensin I, angiotensin II, tetradecapeptide and the tetrapeptide Leu-Val-Tyr-Ser is achieved in a single step, using reversed-phase high-performance liquid chromatography. The application of this technique for the detection of renin activity in crude biological samples, employing the artificial renin substrate tetradecapeptide, is demonstrated. 相似文献
58.
WM. F. Stein M. Dorthy Beck Arthur C. Hollister Jr. Earl Mortenson 《The Western journal of medicine》1951,75(2):94-97
The procedures used in the organization and operation of a special study on diarrheal diseases involving federal, state, and local agencies are outlined. The integration of such a project into a local routine program is discussed and the possible benefits derived by the various agencies are briefly evaluated. 相似文献
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