Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “COELENTERATA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1980

Two new septate junctions in the phylum Coelenterata.

Freeze-fracture of fixed and unfixed tissue, lanthanum tracer and conventional thin-section studies have revealed 2 new types of septate junction in the class Anthozoa, phylum Coelenterata. These new junctions have the 15-18-nm intercellular spacing of all other described septate junctions and are found around the apical circumference of cells lining a lumen or outside edge. However, in freeze-fracture replicas and tangential views of lanthanum-impregnated tissue, they are seen to be quite different from other known septate junction types. One of the new junctions is found in endothelial tissue such as that lining the gut or the inside of the tentacles. In tangential view it is seen to consist of relatively short, straight, double septa, again with lateral projections. In feeeze-fracture of unfixed tissue, the junction consists of double rows of particles on the P face, the particles of one row being rounded, those of the other being elongated at right angles to the line of the septum. This dichotomy in particle size is unexpected, as the 2 halves of the septa as seen in tangential view are symmetrical. In freeze-fracture of fixed material the particle arrays remain on the P face and appear similar to those of unfixed material, but never as clear. In fixed tissue, some distortion had occurred and in extreme cases septa appear as a single broad jumbled row of particles. In this double septa junction, the rows of particles seen in freeze-fracture are occasionally seen to anastomose with a septum dividing into 2 and a third row of particles aligning with the 2 new septa to form their double particle rows. In both fixed and unfixed tissues, the E face of the junction consists of wide, shallow grooves. The second of the new junctions occurs in epithelial tissue, such as around the outer edge of sea-anemone tentacles, and consists of long wavy septa with lateral projections. In views where these projections appear longest, they arise predominantly from one side of the septa. In freeze-fracture of both fixed and unfixed tissue, this junction appears as rows of closely spaced particles on the P face. Occasionally rows of particles are seen on the E face, but usually this face is characterized by shallow grooves. In some aspects these 2 new junctions have features in common with the Hydra type junction also found in the Coelenterata. In all 3 types septa are relatively straight, rather than pleated, and there are lateral projections on the septa.

Animals↗
PubMedDate not supplied

["Synthetical" aiptasia mutabilis RAPP (coelenterata) (author's transl)].

After being cultivated in the dark for some months and after being fed with food free of carotenoids during the time Aiptasia mutabilis (Coelenterata) loses its symbiontic algae (rich in brown fucoxanthin) and becomes transparent white. This disarranged symbiosis may be regenerated under light cultivation by adding different species of Chlorophyceae (Chlorella, Dunaliella) and chrysophyceae (Ochromonas, Cyclotella), but not of Cyanophyceae (Anabaena, Nostoc, Oscillatoria, Anacystis). - This changeable life system between coelenterata and algae may be a good example for further studies of the endosymbiosis problem.

Animals↗
PubMed2004

Antifilarial activity of Zoanthus species (Phylum Coelenterata, Class Anthzoa) against human lymphatic filaria, Brugia malayi.

The chloroform methanol (1:1) extract of an unidentified green zoanthus (Phylum Coelenterata, Class Anthozoa) showed promising in vitro adulticidal activity with a lethal concentration of 125 microg/ml on Brugia malayi. This extract brought about a 52.2% reduction in circulating microfilariae of B. malayi when administered to infected Mastomys coucha at 250 mg/kg, orally for 5 consecutive days. Further fractionation of the extract led to the recovery of four fractions, which were evaluated simultaneously in both in vitro and in vivo systems against B. malayi. The chloroform fraction at 250 mg/kg orally for 5 days exhibited the highest macrofilaricidal action (42.5%), closely followed by the insoluble n-butanol fraction (34.3%), the soluble hexane fraction (32.4%), and the soluble n-butanol fraction (20.4%). In addition, the hexane soluble fraction caused 44.3% sterilization of the surviving female parasites. Two compounds isolated were found devoid of antifilarial activity.

Animals↗
PubMed1994

Possible involvement of arachidonic acid and eicosanoids in metamorphic events in Hydractinia echinata (Coelenterata; Hydrozoa).

Upon induction of metamorphosis, larvae of the marine hydroid Hydractinia echinata release [14C]-arachidonic acid from previously labeled endogenous sources. The lipoxygenase inhibitors nordihydroguaiaretic acid and 5,8,11,14-eicosatetraynoic acid inhibited metamorphosis induced by Cs+ and 1,2-sn-dioctanoylglycerol, whereas the inhibitors of cyclooxygenase, indomethacin, and acetylsalicylic acid were ineffective, suggesting a role for lipoxygenase metabolites of arachidonic acid in induction of metamorphosis. Lipoxygenase products in Hydractinia echinata were isolated and identified by gas chromatography/mass spectrometry. 8- and 12-HETE were the most abundant metabolites. In cytosolic fractions from larvae activity of an arachidonic acid metabolizing enzyme, presumably a lipoxygenase, was found. The metabolic product was identified by 1H-NMR and chiral phase HPLC as 8(R)-HETE. Its production was strongly inhibited by NDGA, but not by indomethacin.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1994

Metamorphosin A: a novel peptide controlling development of the lower metazoan Hydractinia echinata (Coelenterata, Hydrozoa).

Animal development depends on cell communication by signals. We have investigated the role of signals and of signal transduction in the development of the marine hydroid Hydractinia echinata. The larvae undergo metamorphosis in response to a chemical signal provided by environmental bacteria. Metamorphosis can be induced by a variety of different compounds interfering with biochemical signal transduction pathways. Sectioned posterior parts cannot be induced by most compounds known to induce whole larvae to metamorphose. We identified a novel peptide, pGlu-Gln-Pro-Gly-Leu-TrpNH2 ("metamorphosin A"), which induces isolated posterior parts to undergo metamorphosis and hence reactivates pattern formation, cell proliferation, cell differentiation, and morphogenesis. We suggest this peptide to be part of an internal signaling system involved in control of metamorphosis.

Amino Acid Sequence↗
PubMed1984

Synthesis and transport of the organic matrix of the spicules in the gorgonian Leptogorgia virgulata (Lamarck) (Coelenterata: Gorgonacea). An autoradiographic investigation.

The sequence of the synthesis and transport of the organic matrix of spicules has been elucidated in the gorgonian Leptogorgia virgulata by use of 3H-aspartic acid as the tracer in electron-microscopic autoradiography. The entire process of matrix synthesis and transport takes approximately 2 h. It seems that the protein moiety of the organic matrix is synthesized in the RER prior to 5 min following the initial 10 min incubation in the tracer. At the 5 min chase the label is moving from the RER to the Golgi complexes where the carbohydrate moiety of the matrix is presumed to be synthesized. At the 5 to 15 min chases the label is transported out of the Golgi complexes via Golgi vesicles. This phase continues for 30 min. From 60 to 120 min the 3H-aspartic acid moves to the spicules. After 120 min the majority of the label has moved into the spicules. Silver grain counts over both multivesicular and electron-dense bodies remain at relatively low and constant levels over 4 h indicating that neither organelle is involved in the synthesis and transport of the organic matrix.

Animals↗
PubMed1980

Morphology, ultrastructure, and development of the parasitic larva and its surrounding trophamnion of Polypodium hydriforme Ussov (Coelenterata).

The larval stage of Polypodium hydriforme is planuliform and parasitic inside the growing oocytes of acipenserid fishes. The larva has inverted germ layers and a special envelope, the trophamnion, surrounding it within the host oocyte. The trophamnion is a giant unicellular provisory structure derived from the second polar body and performing both protective and digestive functions, clearly a result of adaptation to parasitism. The trophamnion displays microvilli on its inner surface, and irregular protrusions anchoring it to the yolk on its outer surface. Its cytoplasm contains long nuclear fragments, ribosomes, mitochondria, microtubules, microfilaments, prominent Golgi bodies, primary lysosomes, and secondary lysosomes with partially digested inclusions. The cells of the larva proper are poorly differentiated. No muscular, glandular, neural, interstitial, or nematocyst-forming cells have been found. The entodermal (outer layer) cells bear flagella and contain rough endoplasmic reticulum; the ectodermal (inner layer) cells lack cilia and contain an apical layer of acid mucopolysaccharid granules. The cells of both layers contain mitochondria, microtubules, and Golgi bodies; their nuclei display large nucleoli with nucleolonema-like structure, decondensed chromatin, and some perichromatin granules. At their apical rims, the ectodermal cells from septate junctions; laterally, the cells of both layers form simple contacts and occasional interdigitations. The lateral surfaces of entodermal cells are strengthened by microtubules.

Animals↗
PubMed1982

Ultrastructural investigation of spicule formation in the gorgonian Leptogorgia virgulata (Lamarck) (Coelenterata: Gorgonacea).

Ultrastructural examination of original and regenerated branch tips of the gorgonian Leptogorgia virgulata reveals that spicule formation begins with the aggregation of Scleroblasts in the mesoglea. Calcite crystal deposition occurs within a Golgi vacuole containing organic matrix. Vacuole size increases while matrix incorporation and subsequent crystal growth continue, filling the vacuole. At approximately this time, the scleroblasts dissociate and "wart" formation begins. Further spicule growth stretches the cell into a thin envelope. Fusion of vacuole and plasma membrane followed by breach formation during spicule growth, as well as scleroblast atrophy or migration from mature spicules, result in the transition of the spicule from the intracellular to the extracellular environment. The results also reveal aborted spicules and digestive bodies, implying possible relationships among calcification, detoxification, and waste management.

Animals↗
PubMed1996

Cardiac and vascular responses of isolated rat tissues treated with diterpenes from Sinularia flexibilis (coelenterata: octocorallia).

The marine environment is a rich source of compounds with cardiovascular activity. This study characterizes the cardiac and vascular responses in isolated rat tissues of flexibilide, dihydroflexibilide and sinulariolide, three diterpenes isolated from the soft coral Sinularia flexibilis. On rat left ventricular papillary muscles, dihydroflexibilide and flexibilide showed similar potencies (-log EC50 = 4.69 +/- 0.05 and 4.66 +/- 0.06, respectively); the maximal response to dihydroflexibilide of 1.4 +/- 0.2 mN was 35 +/- 7% that of calcium chloride in the same muscles. All diterpenes relaxed rat thoracic aortic rings precontracted with KC1 (100 mM) with similar potencies (flexibilide, -log EC50 = 4.17 +/- 0.06). Flexibilide was further characterized and shown to increase force in isolated rat left atria by 0.8 +/- 0.5 mN at 1 x 10(-4) M, to increase rate of contraction in isolated rat right atria by 18 +/- 5 beta/min at 3 x 10(-5) M and to completely relax endothelium-denuded rat thoracic aortic rings (-log EC50 = 4.14 +/- 0.05). Toxicity as indicated by the occurrence of ectopic beats was not observed with the diterpenes at concentrations which produced complete relaxation of blood vessels, maximal positive inotropic activity and minor positive chronotropic responses. Thus, these compounds may be useful lead compounds in the search for improved treatment of cardiovascular disease, especially heart failure.

Animals↗