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1.
Persoonia ; 51: 280-417, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38665977

RESUMO

Novel species of fungi described in this study include those from various countries as follows: Argentina, Neocamarosporium halophilum in leaf spots of Atriplex undulata. Australia, Aschersonia merianiae on scale insect (Coccoidea), Curvularia huamulaniae isolated from air, Hevansia mainiae on dead spider, Ophiocordyceps poecilometigena on Poecilometis sp. Bolivia, Lecanora menthoides on sandstone, in open semi-desert montane areas, Sticta monlueckiorum corticolous in a forest, Trichonectria epimegalosporae on apothecia of corticolous Megalospora sulphurata var. sulphurata, Trichonectria puncteliae on the thallus of Punctelia borreri. Brazil, Catenomargarita pseudocercosporicola (incl. Catenomargarita gen. nov.) hyperparasitic on Pseudocercospora fijiensis on leaves of Musa acuminata, Tulasnella restingae on protocorms and roots of Epidendrum fulgens. Bulgaria, Anthracoidea umbrosae on Carex spp. Croatia, Hymenoscyphus radicis from surface-sterilised, asymptomatic roots of Microthlaspi erraticum, Orbilia multiserpentina on wood of decorticated branches of Quercus pubescens. France, Calosporella punctatispora on dead corticated twigs of Aceropalus. French West Indies (Martinique), Eutypella lechatii on dead corticated palm stem. Germany, Arrhenia alcalinophila on loamy soil. Iceland, Cistella blauvikensis on dead grass (Poaceae). India, Fulvifomes maritimus on living Peltophorum pterocarpum, Fulvifomes natarajanii on dead wood of Prosopis juliflora, Fulvifomes subazonatus on trunk of Azadirachta indica, Macrolepiota bharadwajii on moist soil near the forest, Narcissea delicata on decaying elephant dung, Paramyrothecium indicum on living leaves of Hibiscus hispidissimus, Trichoglossum syamviswanathii on moist soil near the base of a bamboo plantation. Iran, Vacuiphoma astragalicola from stem canker of Astragalus sarcocolla. Malaysia, Neoeriomycopsis fissistigmae (incl. Neoeriomycopsidaceae fam. nov.) on leaf spots on flower Fissistigma sp. Namibia, Exophiala lichenicola lichenicolous on Acarospora cf. luederitzensis. Netherlands, Entoloma occultatum on soil, Extremus caricis on dead leaves of Carex sp., Inocybe pseudomytiliodora on loamy soil. Norway, Inocybe guldeniae on calcareous soil, Inocybe rupestroides on gravelly soil. Pakistan, Hymenagaricus brunneodiscus on soil. Philippines, Ophiocordyceps philippinensis parasitic on Asilus sp. Poland, Hawksworthiomyces ciconiae isolated from Ciconia ciconia nest, Plectosphaerella vigrensis from leaf spots on Impatiens noli-tangere, Xenoramularia epitaxicola from sooty mould community on Taxus baccata. Portugal, Inocybe dagamae on clay soil. Saudi Arabia, Diaporthe jazanensis on branches of Coffea arabica. South Africa, Alternaria moraeae on dead leaves of Moraea sp., Bonitomyces buffels-kloofinus (incl. Bonitomyces gen. nov.) on dead twigs of unknown tree, Constrictochalara koukolii on living leaves of Itea rhamnoides colonised by a Meliola sp., Cylindromonium lichenophilum on Parmelina tiliacea, Gamszarella buffelskloofina (incl. Gamszarella gen. nov.) on dead insect, Isthmosporiella africana (incl. Isthmosporiella gen. nov.) on dead twigs of unknown tree, Nothoeucasphaeria buffelskloofina (incl. Nothoeucasphaeria gen. nov.), on dead twigs of unknown tree, Nothomicrothyrium beaucarneae (incl. Nothomicrothyrium gen. nov.) on dead leaves of Beaucarnea stricta, Paramycosphaerella proteae on living leaves of Protea caffra, Querciphoma foliicola on leaf litter, Rachicladosporium conostomii on dead twigs of Conostomium natalense var. glabrum, Rhamphoriopsis synnematosa on dead twig of unknown tree, Waltergamsia mpumalanga on dead leaves of unknown tree. Spain, Amanita fulvogrisea on limestone soil, in mixed forest, Amanita herculis in open Quercus forest, Vuilleminia beltraniae on Cistus symphytifolius. Sweden, Pachyella pulchella on decaying wood on sand-silt riverbank. Thailand, Deniquelata cassiae on dead stem of Cassia fistula, Stomiopeltis thailandica on dead twigs of Magnolia champaca. Ukraine, Circinaria podoliana on natural limestone outcrops, Neonematogonum carpinicola (incl. Neonematogonum gen. nov.) on dead branches of Carpinus betulus. USA, Exophiala wilsonii water from cooling tower, Hygrophorus aesculeticola on soil in mixed forest, and Neocelosporium aereum from air in a house attic. Morphological and culture characteristics are supported by DNA barcodes. Citation: Crous PW, Costa MM, Kandemir H, et al. 2023. Fungal Planet description sheets: 1550-1613. Persoonia 51: 280-417. doi: 10.3767/persoonia.2023.51.08.

2.
Pak J Biol Sci ; 11(18): 2201-8, 2008 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-19137828

RESUMO

A contribution to the lichen flora of Turkey is performed. A total of 171 lichen taxa (including 2 subspecies and 2 varieties) and 1 lichenicolous fungus are determined from 14 localities in Antalya, Cankiri, Konya and Nevsehir provinces of Turkey. Caloplaca scrobiculata H. Magn. is new to Turkey. Besides Caloplaca scrobiculata H. Magn. and Xanthoria sorediata (Vain.) Poelt were found for the second time in Asia. Carbonea vitellinaria (Nyl.) Hertel was found to grow on Candelariella vitellina (Hoffm.) Müll. Arg. while Muellerella pymaea (Körb.) D. Hawksw. var. athallina (Müll. Arg.) Triebel (lichenicolous fungus) on Tephromela atra (Huds.) Hafellner as parasitic. All lichen taxa found in Cankiri are new to this province (92 intraspecific taxa), while 39 new to Nevsehir, 8 new to Konya and 5 new to Antalya provinces. For every each taxon, the habitat pattern and distribution data are presented.


Assuntos
Líquens/isolamento & purificação , Líquens/classificação , Líquens/microbiologia , Especificidade da Espécie , Turquia
3.
Hypertension ; 35(6): 1197-202, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10856263

RESUMO

It has been suggested that left ventricular fibrosis in spontaneously hypertensive rats (SHR) is the result of both exaggerated collagen synthesis and insufficient collagen degradation. We have shown previously that chronic treatment with the angiotensin II type 1 receptor antagonist losartan results in diminished synthesis of collagen type I molecules and reversal of myocardial fibrosis in SHR. This study was designed to investigate whether losartan also affects the extracellular degradation of collagen type I fibers in the left ventricle of SHR. The study was performed in 30-week-old normotensive Wistar-Kyoto rats (WKY), untreated SHR, and SHR treated with orally administered losartan (20 mg/kg per day) for 14 weeks before they were killed. Ventricular collagenase activity was determined by degradation of [(14)C]collagen with tissue extracts. Ventricular expression of tissue inhibitor of metalloproteinases 1 (TIMP-1) mRNA was analyzed by Northern blot. A histomorphometric study of the left ventricle was performed in all rats. Compared with WKY, SHR exhibited left ventricular hypertrophy, increased (P<0.05) blood pressure, left ventricular collagen volume fraction and TIMP-1 mRNA, and diminished (P<0.05) collagenase activity. After the treatment period, blood pressure was higher (P<0.05) in losartan-treated SHR than in WKY, and no significant differences were noted in the remaining parameters between the 2 strains of rats. Compared with untreated SHR, treated SHR showed no left ventricular hypertrophy, diminished (P<0.05) blood pressure, left ventricular collagen volume fraction and TIMP-1 mRNA, and increased (P<0.05) collagenase activity. These results suggest that the transcription of the TIMP-1 gene is upregulated in the hypertrophied and fibrotic left ventricle of adult SHR. Upregulation of TIMP-1 may account for diminished collagenase activity in the myocardium of those rats. Chronic angiotensin II type 1 receptor blockade with losartan resulted in inhibition of TIMP-1 expression and stimulation of collagenase activity in the left ventricle of SHR. It is proposed that angiotensin II may facilitate myocardial fibrosis in SHR by depressing the collagenase-mediated extracellular degradation of collagen fibers.


Assuntos
Antagonistas de Receptores de Angiotensina , Colágeno/metabolismo , Matriz Extracelular/metabolismo , Hipertensão/metabolismo , Hipertensão/patologia , Miocárdio/patologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Colagenases/metabolismo , Fibrose , Expressão Gênica , Hipertensão/genética , Hipertensão/fisiopatologia , Hipertrofia Ventricular Esquerda/patologia , Losartan/farmacologia , Masculino , Ratos , Ratos Endogâmicos SHR/genética , Ratos Endogâmicos SHR/fisiologia , Ratos Endogâmicos WKY , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Fatores de Tempo , Inibidor Tecidual de Metaloproteinase-1/genética
4.
Hypertension ; 35(5): 1055-61, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10818064

RESUMO

This study was designed to test the hypothesis that stimulation of nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (NADH/NADPH) oxidase is involved in increased vascular superoxide anion (*O(2)(-)) production in spontaneously hypertensive rats (SHR). The study was performed in 16-week-old and 30-week-old normotensive Wistar-Kyoto rats (WKY(16) and WKY(30), respectively) and in 16-week-old and 30-week-old SHR (SHR(16) and SHR(30), respectively). In addition, 16-week-old SHR were treated with oral irbesartan (average dose 20 mg/kg per day) for 14 weeks (SHR(30)-I). Aortic NADH/NADPH oxidase activity was determined by use of chemiluminescence with lucigenin. The expression of p22phox messenger RNA was assessed by competitive reverse transcription-polymerase chain reaction. Vascular responses to acetylcholine were determined by isometric tension studies. Aortic wall structure was studied, determining the media thickness and the cross-sectional area by morphometric analysis. Whereas systolic blood pressure was significantly increased in the 2 groups of hypertensive animals compared with their normotensive controls, no differences were observed in systolic blood pressure between SHR(30) and SHR(16). No other differences in the parameters measured were found between WKY(16) and SHR(16). In SHR(30) compared with WKY(30), we found significantly greater p22phox mRNA level, NADH/NADPH-driven *O(2)(-) production, media thickness, and cross-sectional area and an impaired vasodilation in response to acetylcholine. Treated SHR had similar NADH/NADPH oxidase activity and p22phox expression as the WKY(30) group. The vascular functional and morphological parameters were improved in SHR(30)-I. These findings suggest that an association exists between p22phox gene overexpression and NADH/NADPH overactivity in the aortas of adult SHR. Enhanced NADH/NADPH oxidase-dependent *O(2)(-) production may contribute to endothelial dysfunction and vascular hypertrophy in this genetic model of hypertension.


Assuntos
Aorta/metabolismo , Proteínas de Membrana Transportadoras , Complexos Multienzimáticos/metabolismo , NADH NADPH Oxirredutases/metabolismo , NAD/metabolismo , Superóxidos/metabolismo , Animais , Aorta/patologia , Tamanho Celular , NADPH Desidrogenase/metabolismo , NADPH Oxidases , Oxigênio/metabolismo , Fosfoproteínas/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY
5.
Gen Comp Endocrinol ; 117(3): 366-80, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10764548

RESUMO

To characterize the endocrine cell types of the pancreas of Rana temporaria, conventional staining, silver impregnation, and immunocytochemical methods for light and electron microscopy have been applied to paraffin, thin and semithin sections, many of them serial pairs. Quantitative data on the frequency and distribution (insular, extrainsular among the exocrine cells, or within the pancreatic ducts) of each endocrine cell type are also reported. Four distinct endocrine cell types have been identified: insulin (B) cells, which are also immunoreactive for [Met]enkephalin; glucagon/PP (A/PP) cells, also immunoreactive for GLP1; somatostatin (D) cells; and a fourth endocrine-like cell type (X cells) of unknown content and function. X cells display characteristic ultrastructure and tinctorial traits but are nonimmunoreactive for all of the 37 antisera tested. The presence of [Met]enkephalin in amphibian pancreatic endocrine cells is now reported for the first time. Almost half (44.9 +/- 7.9) of the total endocrine cell population lies outside the islets, mainly spread among the exocrine cells. Approximately 37.2 +/- 4.6% of the total endocrine cell population was immunoreactive for insulin, 48.8 +/- 6.9% was immunoreactive for glucagon/PP, and 14.0 +/- 4.9% was immunoreactive for somatostatin; 79.2 +/- 6.4% of glucagon/PP cells are found within the exocrine parenchyma, representing the majority (86.4 +/- 4.3%) of extrainsular endocrine component. On the contrary, most B cells (94.2 +/- 2.1%) are located within the islets; 30.8 +/- 12.9% of D cells are found outside the islets.


Assuntos
Pâncreas/citologia , Rana temporaria/anatomia & histologia , Animais , Encefalina Metionina/análise , Glucagon/análise , Imuno-Histoquímica , Insulina/análise , Ilhotas Pancreáticas/citologia , Microscopia Eletrônica , Polipeptídeo Pancreático/análise , Somatostatina/análise
6.
Circulation ; 101(14): 1729-35, 2000 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-10758057

RESUMO

BACKGROUND: This study was designed to investigate whether the serum concentration of the carboxy-terminal propeptide of procollagen type I (PIP), a marker of collagen type I synthesis, is related to myocardial fibrosis in hypertensive patients. METHODS AND RESULTS: The study was performed in 26 patients with essential hypertension in which ischemic cardiomyopathy was excluded after a complete medical workup. Right septal endomyocardial biopsies were performed in hypertensive patients to quantify collagen content. Collagen volume fraction (CVF) was determined on picrosirius red-stained sections with an automated image analysis system. The serum concentration of PIP was measured by specific radioimmunoassay. Compared with normotensives, both serum PIP and CVF were increased (P<0.001) in hypertensives. A direct correlation was found between CVF and serum PIP (r=0.471, P<0.02) in all hypertensives. Histological analysis revealed the presence of 2 subgroups of patients: 8 with severe fibrosis and 18 with nonsevere fibrosis. Serum PIP was higher (P<0.05) in patients with severe fibrosis than in patients with nonsevere fibrosis. Using receiver operating characteristic curves, we observed that a cutoff of 127 microg/L for PIP provided 78% specificity and 75% sensitivity for predicting severe fibrosis with a relative risk of 4.80 (95% CI, 1.19 to 19.30). CONCLUSIONS: These results show a strong correlation between myocardial collagen content and the serum concentration of PIP in essential hypertension. Although preliminary, these findings suggest that the determination of PIP may be an easy and reliable method for the screening and diagnosis of severe myocardial fibrosis associated with arterial hypertension.


Assuntos
Hipertensão/sangue , Hipertensão/patologia , Miocárdio/patologia , Fragmentos de Peptídeos/sangue , Pró-Colágeno/sangue , Adulto , Idoso , Biomarcadores , Biópsia , Colágeno/metabolismo , Ecocardiografia , Feminino , Fibrose , Humanos , Hipertensão/metabolismo , Masculino , Pessoa de Meia-Idade , Curva ROC , Sensibilidade e Especificidade
7.
J Hypertens ; 17(1): 107-14, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10100101

RESUMO

OBJECTIVE: Previous studies have shown that as well as left ventricular hypertrophy, myocardial fibrosis develops early in rats with spontaneous hypertension (SHR). The present study was designed to investigate whether chronic treatment with the angiotensin II type 1 (AT1) receptor antagonist losartan modifies collagen type I metabolism and reverses left ventricular fibrosis in young SHR with left ventricular hypertrophy. DESIGN: The study was performed in 30-week-old normotensive Wistar-Kyoto (WKY) rats, untreated SHR and SHR treated with losartan (20 mg/mg per day, orally) for 14 weeks before they were killed. METHODS: Ventricular pro-alpha 1 (I) collagen messenger RNA was analyzed by Northern blot. Serum levels of the carboxy-terminal propeptide of procollagen type I (PIP) and the pyridoline cross-linked telopeptide domain of collagen type I (CITP) were determined by specific radioimmunoassays as markers of collagen type I synthesis and degradation, respectively. Collagen volume fraction was determined in the left ventricle by quantitative morphometry. RESULTS: Compared with WKY rats, SHR exhibited increased (P < 0.05) mean arterial pressure, pro-alpha 1 (I) collagen messenger RNA, PIP and left ventricular collagen volume fraction, and similar CITP values. After the treatment period, mean arterial pressure was higher (P < 0.05) in losartan-treated SHR than in WKY rats. Compared with untreated SHR, treated SHR showed no left ventricular hypertrophy and diminished (P < 0.05) values of mean arterial pressure, PIP and left ventricular collagen volume fraction. No changes in pro-alpha 1 (I) collagen messenger RNA and CITP values were observed with treatment in SHR. No significant differences in the left ventricular collagen volume fraction were observed between treated SHR with normal blood pressure and treated SHR with abnormally high blood pressure at the end of the treatment period. CONCLUSIONS: These results suggest that chronic AT1 blockade with losartan decreases the post-transcriptional synthesis of fibril-forming collagen type I molecules in young SHR. This effect may be involved in the ability of this drug to reverse left ventricular fibrosis in young rats with genetic hypertension. Apart from its antihypertensive action, other mechanisms may mediate the antifibrotic effect of losartan in this animal model.


Assuntos
Anti-Hipertensivos/farmacologia , Cardiomiopatias/tratamento farmacológico , Colágeno/metabolismo , Hipertensão/tratamento farmacológico , Losartan/farmacologia , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Transcrição Gênica , Animais , Biomarcadores/sangue , Pressão Sanguínea/efeitos dos fármacos , Northern Blotting , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Colágeno/sangue , Colágeno/genética , Colágeno Tipo I , Fibrose/tratamento farmacológico , Fibrose/metabolismo , Fibrose/patologia , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Hipertrofia Ventricular Esquerda/tratamento farmacológico , Hipertrofia Ventricular Esquerda/metabolismo , Hipertrofia Ventricular Esquerda/patologia , Masculino , Peptídeos/sangue , Pró-Colágeno/sangue , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY
8.
Eur Heart J ; 19 Suppl G: G29-33, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9717053

RESUMO

AIM: It has been proposed that alterations of the balance between programmed cell death and cell replication might be involved in abnormalities of smooth muscle cell growth in arterial hypertension. This study was designed to analyse some regulators of apoptosis and proliferation in smooth muscle cells of small intra-myocardial arteries from the left ventricle of adult normotensive Wistar-Kyoto rats (WKY) and adult spontaneously hypertensive rats (SHR). Therefore, we assessed the expression of the cytoplasmic proteins Bax and Bcl-2, respectively a promoter and an inhibitor of apoptosis, and the expression of cyclin A, a nuclear protein that induces proliferation of smooth muscle cells. METHODS AND RESULTS: We measured the percentages of smooth muscle cells expressing these proteins using monoclonal antibodies and the avidin-biotin immunoperoxidase method. Compared with WKY, cells from SHR exhibited normal Bax expression, increased (P < 0.001) Bcl-2 expression and increased (P < 0.001) cyclin A expression. The ratio of Bax to Bcl-2, an index of cell susceptibility to apoptosis, was lower (P < 0.001) in SHR than in WKY. Systolic blood pressure was directly correlated (P < 0.01) with Bcl-2 and cyclin A in SHR. CONCLUSION: These results suggest that apoptosis and proliferation of smooth muscle cells might be inhibited and stimulated, respectively, in small arteries of adult SHR. The imbalance between these two processes may account for abnormalities of smooth muscle cell growth in the arterial wall in genetic hypertension.


Assuntos
Apoptose/fisiologia , Divisão Celular/fisiologia , Vasos Coronários/patologia , Hipertensão/patologia , Músculo Liso Vascular/patologia , Animais , Ciclina A/metabolismo , Masculino , Miocárdio/patologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY
9.
Hypertension ; 32(2): 280-6, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9719055

RESUMO

An association of increased apoptosis with overactivity of the local angiotensin-converting enzyme has been reported in cells from the left ventricle of adult rats with spontaneous hypertension (SHR). To gain insight into the regulation of cardiac apoptosis in arterial hypertension, we investigated the expression of the proteins Bcl-2 (an inhibitor of apoptosis) and Bax (an inducer of apoptosis) in the left ventricle of 30-week-old normotensive Wistar-Kyoto rats (WKY), SHR, and SHR treated with the angiotensin II type 1 receptor (AT1) antagonist losartan (20 mg x kg(-1) x d(-1)) during 14 weeks before death. The density of apoptotic cells was assessed by direct immunoperoxidase detection of biotin-labeled deoxyuridin nucleotides. The expression of Bcl-2 and Bax was assessed by Western blot analysis. Compared with WKY, untreated SHR exhibited increased (P<0.05) apoptosis, increased (P<0.01) Bax, and similar Bcl-2. The Bcl-2/Bax ratio (an inverse index of cell susceptibility to apoptosis) was lower (P<0.05) in untreated SHR than in WKY. The chronic administration of losartan was associated with the normalization of apoptosis, Bax expression, and the Bcl-2/Bax ratio in treated SHR. No changes in the expression of Bcl-2 were observed in these rats after treatment. No significant changes in the apoptotic density were observed between treated SHR with normal blood pressure and treated SHR with abnormally high blood pressure at the end of the treatment period. These results suggest that an association exists between increased apoptosis and overexpression of Bax oncoprotein in cells from the left ventricle of adult SHR. Chronic blockade of AT1 receptors prevents Bax overexpression and normalizes apoptosis in the left ventricle of SHR independently of its hemodynamic effect. On the basis of our findings, it can be proposed that the interaction of angiotensin II with its AT1 receptors may participate in the stimulation of Bax protein, which in turn renders cells from the left ventricle of SHR more susceptible to apoptosis.


Assuntos
Anti-Hipertensivos/farmacologia , Apoptose/fisiologia , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Hipertensão/metabolismo , Hipertensão/patologia , Losartan/farmacologia , Proteínas Proto-Oncogênicas/biossíntese , Animais , Anti-Hipertensivos/uso terapêutico , Apoptose/efeitos dos fármacos , Ventrículos do Coração/fisiopatologia , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Losartan/uso terapêutico , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Ratos , Ratos Endogâmicos SHR , Função Ventricular Esquerda/efeitos dos fármacos , Proteína X Associada a bcl-2
11.
J Morphol ; 216(3): 339-50, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8315652

RESUMO

Pancreatic ducts of young posthatching Rana temporaria tadpoles are the main component of the developing pancreas. At this stage (free-swimming tadpoles with internal gills), duct cells display a high degree of development of basal and lateral outfoldings of the cell membrane with extensive interdigitation, and numerous mitochondria are present throughout the cytoplasm. Wide intercellular spaces also exist, sometimes forming canaliculi-like structures. Since these traits are characteristic of cells engaged in osmotic regulation, we suggest the possibility that this temporary duct system participates in such control. Duct cells in tadpoles with well-developed hindlegs have diminished interdigitation, and mitochondria are localized apically.


Assuntos
Mitocôndrias/ultraestrutura , Ductos Pancreáticos/embriologia , Rana temporaria/embriologia , Equilíbrio Hidroeletrolítico/fisiologia , Animais , Diferenciação Celular/fisiologia , Larva/citologia , Larva/crescimento & desenvolvimento , Ductos Pancreáticos/citologia
12.
Cell Tissue Res ; 264(1): 139-50, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2054839

RESUMO

The pancreatic endocrine component was studied at different stages of development in the tadpoles of Rana temporaria. The material was embedded in Epon, and serial semithin and thin sections were made in order to correlate ultrastructural features and tinctorial traits of the endocrine cells. Serial semithin sections were also stained with the peroxidase-antiperoxidase immunocytochemical method and with silver impregnations for argyrophilia and argentaffinity. In early larvae (legless tadpoles). A and B cells are present. Both can be found within ducts and exocrine tissue or, more frequently, in cellular clusters among the ducts and acini. These primitive islets are solid structures, surrounded but not penetrated by capillaries. Mitoses were observed in A and B cells. In the following phase (tadpoles with hindlegs), D and pancreatic polypeptide-immunoreactive cells are also present, as well as numerous endocrine cells scattered among exocrine tissue. There is also a change in the vascular-insular pattern: capillaries not only surround but also penetrate the endocrine group. The structure of the endocrine pancreas in older tadpoles is similar. Tinctorial traits and ultrastructural features of endocrine cells are described, and the origin of primitive islets is discussed.


Assuntos
Ilhotas Pancreáticas/crescimento & desenvolvimento , Rana temporaria/crescimento & desenvolvimento , Animais , Diferenciação Celular , Imuno-Histoquímica , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/ultraestrutura , Larva/metabolismo , Larva/ultraestrutura , Microscopia Eletrônica , Rana temporaria/metabolismo
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