0000000001062108
AUTHOR
Paolo D'agati
Espressione dell'attività acetilcolinesterasica nelle cellule lateralidel tronco della larva e negli emociti di Ascidie solitarie
Presence of thyroid hormones in ascidian larvae and their involvement in metamorphosis
In this study we investigated the presence and localization of thyroxine in Ciona intestinalis larvae and its involvement in metamorphosis. To date, the mechanisms regulating the metamorphosis of ascidians remain largely unknown. In vivo treatment of swimming larvae with exogenous L-thyroxine and thiourea, and in vitro experiments utilizing high performance liquid chromatography, radioimmunoassay, and immunoperoxidase staining demonstrate the presence of thyroxine at the larval stage. This suggests that this hormone may participate in the control of metamorphosis and thus play a different role from that observed in adults.
APOPTOSIS IN ASCIDIAN LARVAE AFTER TRIBUTYLTIN-CHLORIDE TREATMENT
Synthesis, structural investigations on organotin(IV) chlorin-e6 complexes, their effect on sea urchin embryonic development and induced apoptosis
Four new organotin(IV) chlorin derivatives, [chlorin=chlorin-e(6)=21H,23H-porphine-2-propanoic acid, 18-carboxy-20-(carboxymethyl)-8-ethenyl-13-ethyl-2,3-di-hydro-3,7,12,17-tetramethyl-(2S-trans)-], with formula (R(2)Sn)(3)(chlorin)(2).2H(2)O (R=Me, n-Bu) and (R(3)Sn)(3)chlorin.2H(2)O (R=Me, Ph) have been synthesized. The solid state and solution phase structures have been investigated by FT-IR, (119)Sn Mössbauer, (1)H and (13)C NMR spectroscopy. In the solid state, (R(2)Sn)(3)(chlorin)(2).2H(2)O complexes contain six coordinated Sn(IV), in a skew trapezoidal environment by forming trans-R(2)SnO(4) polymeric units. As far as (R(3)Sn)(3)chlorin.2H(2)O complexes are concerned, Sn(IV) is five …
Further data on expression of acetylcholinesterase during oogenesis and embryonic development of Ciona intestinalis and Ascidia malaca (Ascidiacea,Urochordata): a biochemical and histochemical study
Effects of sublethal levels of tributyltin chloride on a new toxicity test organism,Liza saliens (osteichthyes, mugilidae): a histological study
The histopathological effects of 10−7 and 10−9M tributyltin(IV)chloride,TBTCl, solutions on different Liza saliens organs have been studied by light microscope. The fish were sacrificed after 3–4 h incubation in 10−7M TBTCl solution or after 15 days incubation in 10−9M solution. The observed histopathological changes were dose- and time-dependent. The 10−7M TBTCl concentration resulted in major damage to the gill epithelium, indicating that TBTCl primarily interfered with the respiration, osmoregulation, acid balance and nitrogenous waste excretion processes. After incubation in 10−9M TBTCl solution the fish lived 20 or more days, but many of the organs were altered. Thymus atrophy, reduced…
Lipid and fatty acid variations inCiona intestinalis ovary after tri-n-butyltin(IV)chloride exposure
Reduction of total lipids (TL) content and significant variations of triglyceride (TG) and phospholipid (PL) fractions were observed as a consequence of exposure of Ciona intestinalis ovaries to tributyltin chloride (TBTCL) solutions. In particular, an evident TG decrease and a PL increase were observed, which probably provoked an increment in membrane fluidity, because of the high concentration of long chain fatty acids and, as a consequence, PL. This could be a cell adaptive standing mechanism towards the pollutants, as observed in Saccharomyces cerevisiae. Also the increase in the content of the polyunsaturated fatty acids (PUFA), important in the synthesis of compounds such as prostagla…
Synthesis, structural investigations on organotin(IV) chlorin-e6 complexes, their effect on sea urchin embryonic development and induced apoptotic changes
Effects of sublethal levels of tributyltin chloride on a new toxicity test organism, Liza saliens (Osteichthyes, Mugilidae)
The histopathological effects of 10−7 and 10−9 M tributyltin(IV)chloride,TBTCl, solutions on different Liza saliens organs have been studied by light microscope. The fish were sacrificed after 3–4 h incubation in 10−7 M TBTCl solution or after 15 days incubation in 10−9 M solution. The observed histopathological changes were dose- and time-dependent. The 10−7 M TBTCl concentration resulted in major damage to the gill epithelium, indicating that TBTCl primarily interferedwith the respiration, osmoregulation, acid balance and nitrogenous waste excretion processes. After incubation in 10−9 M TBTCl solution the fish lived 20 or more days, but many of the organs were altered. Thymus atrophy, red…
Synthesis and structural investigations on R2Sn(IV)-D-aldonic acid complexes (R = methyl; butyl). Their effect on a new toxicity test organism,Liza saliens(Osteichthyes, Mugilidae): a histological study
Eight R2Sn(IV)-D-aldonate complexes [(R = Me, Bu; D-aldonate = D-galactonate2− (Galn), D-Gluconate2− (Glun), D-Gulonate2− (Guln), D-Ribonate2− (Ribn)], five of which are new derivatives, have been synthesized and structurally characterized both in solid and solution state by IR, 119Sn Mossbauer and 1H, 13C, 119Sn NMR spectroscopies, showing that ligands act as dianonic chelating agents. In solution phase, NMR data suggest that the bidentate chelation is attained by the O1 carboxylate and the vicinal O2 alkoxide atoms, which can be dynamically extended to a third binding site (O4) competing with O2. In Me2Sn(IV)-D-gluconate complex the occurrence of a self-association process leading to a di…
Effects of tributyltin(IV) chloride on fertilization ofStyela plicata(Ascidiacea: Tunicata): II. Scanning and transmission electron microscopy studies
The morphological aspects of Styela plicata fertilization after treatment with tributyltin(IV) chloride are described by means of scanning and transmission electron microscopy investigations. Alterations have been shown both on female and male gametes; spermatozoa, all the egg envelopes and the mitochondria of the egg cortical cytoplasm are modified in relation to incubation time. As a consequence, the damage to gametes blocks sperm–egg interaction and fertilization does not occur. Copyright © 2003 John Wiley & Sons, Ltd.
Organometallic complexes with biological molecules: XVI. Endocrine disruption effects of tributyltin(IV)chloride on metamorphosis of the ascidian larva
The effects of tributyltin(IV)chloride (TBT) on the metamorphosis of ascidian larvae of Ciona intestinalis, 2 h after hatching, were investigated. Ascidians are protochordates that lack thyroid follicles and possess thyroid hormones (THs) and their precursors, 3-monoiodo-tyrosine (MIT) and 3,5-diiodo-tyrosine (DIT), in their endostyle. According to recent findings, these hormones are also present at larval stages, localize in mesenchymal cells and their function seems to be mainly related to larval transformations. Here, we investigate the effects of TBT on thyroxine (T4) content and localization by exposing larvae of C. intestinalis for different times to TBT concentrations known to block …
Interference of tributyltin(IV)chloride on the vascular plant cells
In the recent past years, interest in the environmental impact of organotin(IV) compounds has risen markedly. Considering that most data in the scientific literature refers to the animal kingdom and not to higher plants cells, we tested the effects of organotin compounds on vascular plant cells, by studying the interaction of tributyltin chloride (TBTCl) with Allium cepa, Solanun tuberosum and Solanum melongena, vascular plants that are directly involved in the human food chain. The TBTCl effects on mitotic metaphase plates, on pollen grains and on both microtubers and adult tuber parenchymatic cells were investigated and the concentrations of TBTCl inside the treated parenchymatic cells we…
Coordination properties of the ACE inhibitor captopril towards Me2Sn(IV)2+ in aqueous solution, and biological aspects of some dialkyltin(IV) derivatives of this ligand
Abstract The coordination of Me 2 Sn(IV) 2+ (M) to captopril { N -[( S )-3-mercapto-2-methylpropionyl]- l -proline, H 2 (cap), H 2 L} in aqueous solution was studied by means of potentiometric titration, electrospray mass spectrometry, 1 H-NMR spectroscopy and Mossbauer spectroscopy in the pH range 2–11 ( I =0.1 mol dm −3 NaClO 4 , 298 K). The results obtained with these methods proved that only monomeric complexes are formed in solution. In the acidic pH range, species with a metal-to-ligand ratio of 1:1 exist. The neutral complex ML, similarly to the complex Me 2 Sn(cap) crystallized in the same pH range, adopts a tbp structure with eq S − and ax COO − , while, instead of the coordina…
Embryotoxicity studies of tri-n-butyltin(IV) complexes of 5-[(E)-2-(aryl)-1-diazenyl]-2-hydroxybenzoic acid and 2-[(E)-2-(3-formyl-4-hydroxyphenyl)-1-diazenyl] benzoic acid on sea urchin development
The toxicity studies of free 5-[(E)-2-(aryl)-1-diazenyll-2-hydroxybenzoic acid and 2-[(E)-2-(3-formyl-4-hydroxyphenyl)-1-diazenyllbenzoic acid and their tri-n-butyltin(IV) complexes were evaluated by using sea urchin early developmental stages as recommended model organisms for toxicity tests. The novel complexes, as the parent tri-n-butyltin(IV) chloride (TBTCl), caused mitosis block and induced high embryonic mortality in sea urchin. Copyright (c) 2005 John Wiley & Sons, Ltd.