Publicaciones por año
Publicaciones del Departamento de Histología y Embriología
Intrinsic neuronal cell bodies in the rat ovary
Neurosci Lett 1996 205(1):65-7
The present study describes ganglia and isolated neurones in the ovary of the Wistar rat, employing histological and histochemical techniques. Four kinds of ganglia in the postpubertal and young adult rat were identified: the mesovarial, hilar, medullary and cortical ganglia. Isolated neurones were also found, being dispersed along blood vessels in the ovary medulla and near the follicles. The soma diameters of these neuronal cells ranged from 25 to 50 microns. In the prepubertal rat, only the mesovarial and hilar ganglia were observed. They contained small neurones with soma diameters ranging from 10 to 15 microns. NADPH-diaphorase activity was detected in some isolated neurones and in the cortical and hilar ganglia in all rats examined.
Laboratory of Biology of Reproduction, Department of Histology and Embryology, School of Medicine, Gral. Flores 2125, CP 11800, Montevideo, Uruguay
DOI: 10.1016/0304-3940(96)12361-2
PMID: 8867022
Pubmed: https://pubmed.ncbi.nlm.nih.gov/8867022
Texto completo: https://linkinghub.elsevier.com/retrieve/pii/0304394096123612
Abstract:
The present study describes ganglia and isolated neurones in the ovary of the Wistar rat, employing histological and histochemical techniques. Four kinds of ganglia in the postpubertal and young adult rat were identified: the mesovarial, hilar, medullary and cortical ganglia. Isolated neurones were also found, being dispersed along blood vessels in the ovary medulla and near the follicles. The soma diameters of these neuronal cells ranged from 25 to 50 microns. In the prepubertal rat, only the mesovarial and hilar ganglia were observed. They contained small neurones with soma diameters ranging from 10 to 15 microns. NADPH-diaphorase activity was detected in some isolated neurones and in the cortical and hilar ganglia in all rats examined.
alpha-Crystallin polypeptides in developing chicken lens cells
Exp Eye Res 1995 61(2):181-7
A de Maria , C Arruti
Departamento de Biología Celular, Facultad de Ciencias and Laboratorio de Cultivo de Tejidos, Facultad de Medicina, Universidad de la República, Avda. General Flores 2125, 11800 Montevideo, Uruguay
DOI: 10.1016/s0014-4835(05)80038-7
PMID: 7556482
Pubmed: https://pubmed.ncbi.nlm.nih.gov/7556482
Texto completo: https://www.sciencedirect.com/science/article/abs/pii/S0014483505800387?via%3Dihub
Abstract:
We provide evidence that the different cells that form the chicken lens have isoelectric variants of alpha-crystallins at early and late developmental stages. We separated the alpha A and alpha B-crystallin subclasses by sodium dodecylsulphate polyacrylamide gel electrophoresis and then further resolved each by isoelectric focusing and assays with specific anti alpha-crystallin antibodies. We found that the annular pad, cortical and nuclear fibers, as well as the epithelial cells, contain alpha A and alpha B native chains and their respective isoelectric variants. These results on adult and embryonic lenses obtained a short time after the onset of alpha-crystallin expression suggest that lens cells, having different phenotypes, are able to produce post-translational modifications of the alpha A and alpha B chains as a part of their developmental program.
Neonatal acetylcholinesterase inhibition by fasciculin 2 in rats: a model for the study of central nervous system development?
Toxicon 1995 Jul;33(7):909-16
B Bolioli 1 , F Blasina 1, R Silveira 2, F Dajas 3
1 Histology Department, Faculty of Medicine, Institute de Investigaciones Biológicas Clemente Estable, Avda. Italia 3318, Montevideo, Uruguay 2 Cell Biology Division, Institute de Investigaciones Biológicas Clemente Estable, Avda. Italia 3318, Montevideo, Uruguay 3 Neurochemistry Division, Institute de Investigaciones Biológicas Clemente Estable, Avda. Italia 3318, Montevideo, Uruguay
DOI: 10.1016/0041-0101(95)00025-h
PMID: 8588215
Pubmed: https://pubmed.ncbi.nlm.nih.gov/8588215
Texto completo: https://linkinghub.elsevier.com/retrieve/pii/0041-0101(95)00025-H
Abstract:
Fasciculin 2 (FAS), a potent acetylcholinesterase (AChE, EC 3.1.1.7) inhibitory peptide with affinity for the enzyme in the nanomolar range was utilized together with two other AChE inhibitors (Paroxon and BW284c51) to study the role of AChE in central nervous system development. When drugs were intracisternally injected at postnatal days 3 and 5, only FAS showed a significant inhibition of hippocampus and striatum AChE (39% and 77% inhibition, respectively). After FAS treatment, animals showed convulsive behaviour which was blocked by subcutaneous pretreatment with atropine sulfate (10 mg/kg). An assessment of developmental indices showed no alteration in neurological reflex maturation, motor behaviour or cell morphology. Body weight gain was significantly lower only in FAS-treated animals compared to controls during the preweaning period. To investigate the specificity of this effect a synthetic loop of FAS (showing no activity in vitro or in vivo) and oxidized FAS (showing a weak inhibition in vitro and no activity in vivo) were also intracisternally injected. Animals injected with the loop showed normal body weight development while those treated with oxidized FAS showed impairment in body weight. In conclusion, FAS was the most potent drug at inhibiting neonatal AChE in vivo without nonspecific brain damage. Impairment in body weight seems to be dependent on AChE involvement, although the possibility of a direct FAS effect is discussed. These results point to FAS intracisternal treatment as a useful in vivo model to study the role of AChE in the critical period of early postnatal central nervous system development.
Characterisation of eye-lens DNases: long term persistence of activity in post apoptotic lens fibre cells
Cell Death Differ 1995 2(1):47-56
C Arruti 1 , E Chaudun 2 , A De Maria 1 , Y Courtois 2 , M F Counis 3
1 Departamento de Biologia Celular, Facultad de Ciencias y Laboratorio de Cultivo de Tejidos, Facultad de Medicina, Avda, Gral, Flores 2125, Montevideo, Uruguay 2 Unité de Recherches Gérontologique, CNRS, Association Claude Bernard, 29 rue Wilhem, 75016 Paris, France 3 Unité 118 INSERM, 29 rue Wilhem, 75016, Paris, France
DOI:
PMID: 17180015
Pubmed: https://pubmed.ncbi.nlm.nih.gov/17180015
Texto completo:
Abstract:
Fibre cells in the ocular lens exhibit a constitutive apoptotic process of nuclear degradation that includes chromatin breakage, generating a ladder pattern of DNA fragments. This process is intrinsic to the normal terminal differentiation program. Despite the loss of nucleus and cytoplasmic organelles, the terminal differentiated fibre cells remain in the lens during the whole life span of the individual. The lens cells thus provide a unique system in which to determine the presence and fate of endonucleases once the chromatin has been cleaved. We report here on the presence of DNase activity in nucleated and anucleated lens cells. Using a nuclease gel assay and double-stranded DNA as substrate, we found active 30 and 60 kDa DNases. The enzymatic activities were Ca(2+), Mg(2+) dependent, and active at neutral pH. The relative amount of these forms changed during development and aging of the lens fibre cells. Both forms were inhibited by Zn(2+), aurintricarboxylic acid, and G-actin. The proteins were also separated by SDS-PAGE, renatured after removing SDS and incubated in the presence of native DNA adsorbed to a membrane. Therefore it was possible to demonstrate, by means of a nick translation reaction, that the enzymes produced single strand cuts. Based on these findings we propose that these chick lens nucleases are probably related to DNase I.
DNA strand breakage during physiological apoptosis of the embryonic chick lens: free 3' OH end single strand breaks do not accumulate even in the presence of a cation-independent deoxyribonuclease
J Cell Physiol 1994 158(2):354-64
E Chaudun 1 , C Arruti 2 , Y Courtois 1 , F Ferrag 1 , J C Jeanny 1 , B N Patel 3 , C Skidmore 3 , A Torriglia 1 , M F Counis 1
1 Unité de Recherches Cerontologiques 118 INSERM, UA 630 CRNS, Association Claude Bernard, 29 rue Wilhem, 75016 Paris, France (E.C., Y.C., F.F., I.C.)., A.T., M.F.C.); 2 Laboratorio de Cultivo de Tejidos, Departarnento de Histologia y Embriologia, Facultad de Medicina, Montevideo, Uruguay, (C.A.); 3 Department of Biochemistry and Physiology, University of Reading, Reading RC6 LA), England (B.N.P., C,S)
DOI: 10.1002/jcp.1041580218
PMID: 8106572
Pubmed: https://pubmed.ncbi.nlm.nih.gov/8106572
Texto completo: https://doi.org/10.1002/jcp.1041580218
Abstract:
Epithelial cells from the lens equator differentiate into elongated fiber cells. In the final steps of differentiation, the chromatin appears quite condensed and chromatin breakdown into nucleosomes occurs. DNA breaks due to an endodeoxyribonuclease activity corresponding to at least two polypeptides of 30 and 40 kDa have been identified. To identify the nature and the developmental appearance of initial breaks, nick translation reaction was followed both biochemically and in situ in fiber and epithelial cells from chick embryonic lenses. There is no accumulation of single-strand breaks (SSB) with 3'OH ends in lens fiber cells during embryonic development. Such damage can be increased in these cells by treatment with DNAase I indicating the absence of an inhibitor of the nick translation reaction in fiber cells. However, there are indications of the presence of DNA breaks with blocked termini when the phosphatase activity of nuclease P1 is used. The presence of breaks is also indicated by the large amounts of (ADP-ribose)n found in lens fibers particularly at 11 days of embryonic development (E11) as ADP-ribosyl transferase binds to and is activated by DNA strand breaks. Incubation of lens cells in vitro, which causes nucleosomal fragmentation only in fiber cells, produces SSB with 3'OH ends in both epithelia and fibers. Incubation for short periods, observed in experiments in situ, induces SSB first in the central fiber nuclei, which are late in differentiation. This may indicate that these SSB play a physiological role. Long incubations produce larger numbers of SSB in epithelia than fibers. The SSB in the fibers may have been converted into double-strand breaks (D SB), seen as nucleosomal fragments, and therefore no longer act as substrates for nick translation. The nuclease activity responsible for SSB production is independent of divalent cations and could be implicated in lens terminal differentiation.
An improved method combining two electrophoretic procedures: application to the separation of lens alpha-crystallin isoforms
1991 Jul-Aug;12(7-8):588-91
C Arruti 1 3 , S Chifflet 2 3
1 Departamento de Histología y Embriología, Facultad de Medicina, Montevideo, Uruguay. 2 Departamento de Bioquimica, Facultad de Medicina, Montevideo 3 Departamento de Biologia Celular, Faculted de Ciencias, Montevideo
DOI: 10.1002/elps.1150120720.
PMID: 1915250
Pubmed: https://pubmed.ncbi.nlm.nih.gov/1915250
Texto completo: https://doi.org/10.1002/elps.1150120720
Abstract:
Polypeptides having different net electric charges and very similar molecular weights, visualized as one single band in sodium dodecyl sulfate--polyacrylamide gel electrophoresis (SDS-PAGE), can be readily analyzed by an improved method combining two electrophoretic procedures. The methodology consists of the identification and isolation of selected protein bands from SDS-PAGE, their equilibration in an isoelectric focusing (IEF) sample buffer, and their casting and separation in an IEF flat-bed gel. This method requires no extra equipment, is highly reproducible, is suitable for quantitative and comparative studies, and is especially useful in the case of small samples. As a particular example, we analyze here the subunit composition of alpha-crystallins of young and embryonic quail lenses.
Localization of basic fibroblast growth factor binding sites in the chick embryonic neural retina
Differentiation 1990 Dec;45(3):161-7
A Cirillo 1 , C Arruti 1 2, Y Courtois 3, J C Jeanny 3
1 Laboratorio de Cultivo de Tejidos, Depto de Histología y Embriología, Facultad de Medicina, Avda General Flores 2125, 11800 Montevideo, Uruguay 2 Depto de Biologia Celular, Facultad de Humanidades y Ciencias, Tristin Narvaja 1464, 11200 Montevideo, Uruguay 3 Unité de Recherches Gérontologiques, INSERM U. 118, Unité Affilié CNRS, 29, rue Wilhem, F-75016 Paris, France
DOI: 10.1111/j.1432-0436.1990.tb00469.x
PMID:
Pubmed: https://pubmed.ncbi.nlm.nih.gov/
Texto completo: https://linkinghub.elsevier.com/retrieve/pii/S0301-4681(11)60217-X
Abstract:
We have investigated the localization of basic fibroblast growth factor (bFGF) binding sites during the development of the neural retina in the chick embryo. The specificity of the affinity of bFGF for its receptors was assessed by competition experiments with unlabelled growth factor or with heparin, as well as by heparitinase treatment of the samples. Two different types of binding sites were observed in the neural retina by light-microscopic autoradiography. The first type, localized mainly to basement membranes, was highly sensitive to heparitinase digestion and to competition with heparin. It was not developmentally regulated. The second type of binding site, resistant to heparin competition, appeared to be associated with retinal cells from the earliest stages studied (3-day-old embryo, stages 21-22 of Hamburger and Hamilton). Its distribution was found to vary during embryonic development, paralleling layering of the neural retina. Binding of bFGF to the latter sites was observed throughout the retinal neuroepithelium at early stages but displayed a distinct pattern at the time when the inner and outer plexiform layers were formed. During the development of the inner plexiform layer, a banded pattern of bFGF binding was observed. These bands, lying parallel to the vitreal surface, seemed to codistribute with the synaptic bands existing in the inner plexiform layer. The presence of intra-retinal bFGF binding sites whose distribution varies with embryonic development suggests a regulatory mechanism involving differential actions of bFGF on neural retinal cells.
Depletion of the Ca(++)-dependent releasable pool of glutamate in striatal synaptosomes associated with dendrotoxin-induced potassium channel blockade
J Neural Transm Gen Sect 1990 80(3):167-79
L Barbeito, J Siciliano, F Dajas
Neurochemistry Division, Faculty of Medicine, Montevideo, Uruguay, and Histology Department, Faculty of Medicine, Montevideo, Uruguay
DOI: 10.1007/BF01245118
PMID: 1970482
Pubmed: https://pubmed.ncbi.nlm.nih.gov/1970482
Texto completo: https://link.springer.com/article/10.1007/BF01245118
Abstract:
The presynaptic actions of the potassium channel blocker Dendrotoxin (DTX) on the Ca+2-dependent release of endogenous glutamate (GLU) and aspartate (ASP) have been tested in synaptosome-enriched preparations from rat striatum. 24 hours after the intrastriatal administration of DTX the K(+)-evoked release of GLU and ASP from the striatal synaptosomes was decreased by 40-45%. No changes in the total synaptosomal content of the amino acids were observed. Superfusion of immobilized synaptosomes with DTX or 4-amino-pyridine resulted in a dose-dependent increase in the basal outflow of GLU and ASP. The release of GLU stimulated by DTX was Ca+2-dependent and was not abolished by superfusing the synaptosomes with 50 microM D-ASP. Moreover, continuous superfusion of DTX (7 microM) to synaptosomes almost completely dumped the subsequent release of GLU and ASP stimulated by 20 mM K+. It is concluded that blockade of presynaptic K+ channels by DTX leads to a massive release of the transmitter pool of GLU (and possible also ASP) from isolated nerve terminals and to a depletion of the amino acid releasable pool.
The effect of eye-derived-growth-factor (EDGFs) on methionine incorporation in the different cell populations of bovine adult lens in organ culture
Exp Eye Res 1989 48(2):177-86
F Mascarelli 1 , Y Courtois 1 , C Arruti 2
1 Unité de Recherches Gérontologiques. U. 118 INSERM, 29 rue Wilhem, 75016 Parix, France 2 Laboratorio de Cultivo de Tejidos, Departamento de Histologia y Embriologia, Facultad de Medicina, Avenida General Flores, 2125 Montevideo, Uruguay
DOI: 10.1016/s0014-4835(89)80068-5
PMID: 2924806
Pubmed: https://pubmed.ncbi.nlm.nih.gov/2924806
Texto completo: https://www.sciencedirect.com/science/article/abs/pii/S0014483589800685?via%3Dihub
Abstract:
When adult bovine lenses were cultured in vitro, the purified retina-derived growth factors EDGF I or EDGF II, as well as the soluble fraction of the retina RE, increased the rate of incorporation of [35S]methionine into protein in cells belonging to different populations in the anterior epithelium as well as in fibers from the most superficial region of the cortex. These fiber cells were the most sensitive to stimulation by the retinal factors as they exhibit a significant increase of total protein synthesis 24 hr after addition of the factors to the culture medium. The epithelial cells studied--central epithelial cells and germinative cells--appeared stimulated only 1 day later. The stimulation of incorporation was not directed towards a particular subset of proteins but to all major polypeptides constituting the electrophoretic pattern of each cell population. It is suggested that this type of ocular signal, which stimulates the expression of a definite program, may act as a permissive signal.
Intrastriatal dendrotoxin injection: behavioral and neurochemical effects
Toxicon 1988 26(11):1009-15
R Silveira, J Siciliano, V Abo, L Viera, F Dajas
Neurochemistry Division, Instituto de Investigaciones Biologicas Clemente Estable, Montevideo, Uruguay, and Histology Department, Faculty ofMedicine, Montevideo, Uruguay
DOI: 10.1016/0041-0101(88)90199-7
PMID: 3245048
Pubmed: https://pubmed.ncbi.nlm.nih.gov/3245048
Texto completo: https://www.sciencedirect.com/science/article/abs/pii/0041010188901997
Abstract:
Unilateral striatal injection of dendrotoxin (DTX), a polypeptide isolated from the venom of the snake Dendroaspis angusticeps, in rats provoked a complex behavioral syndrome characterized by spontaneous circling towards the contralateral side, stereotypic like chewing movements and gnawing, abnormal postures and convulsions. All these symptoms achieved their maximum on the first day, disappearing during the first week after injection. Neurochemical analyses of striatal monoamines and monoamine metabolites showed a significant increase of dopamine and serotonin metabolites 20 hr after DTX injection. A group of animals sacrificed 15 days after toxin administration showed normal levels of monoamines and their metabolites, except for homovanillic acid levels which were still significantly increased. These data indicate that monoamines are involved in the behavioral syndrome elicited by DTX and are possibly related to its excitatory effect upon brain structures in vivo.