Características regionais sobre a ultra-estrutura das células principais do epitélio do ducto epididimal de Agouti paca

The principal (P) cells of epididymidis surface epithelium of Agouti paca were related to processes of adsorptive endocvtosis and phase-fluid endocvtosis, as well as protein secretion apparently also occur. These findings had been proposed on the base the cytoplasmic ultrastructural features of P cells in which were seen an expressive number of vesicles with several shapes, sizes and internalized content occurring also smaller pits and pale small vesicles located next to the apical brush border of microvilli. Moreover, occurred coated vesicles, smooth surface vesicles and great vesicles; multivesicular bodies, endosomes and lysosomes mainly viewed on supranuclear and apical positions. Presence of an appocrine secretory pathway was characterized in P cells through the occurrence of apical cytoplasmic expansions, protruding into the ducts epididymidis lumina) compartment.

Structural and ultrastructural aspects of ontogenesis and differentiation of resin secretory cavities in Hymenaea stigonocarpa (Fabaceae-Caesalpinioideae) leaves

Cell lysis in the formation of secretory cavities in plants has been questioned by some authors and considered as result of technical artifacts. To describe the formation of secretory resin cavities in Hymenaea stigonocarpa leaves, leaflet samples at different stages of differentiation were collected, fixed, and processed for light and electron microscopy as per usual methods. The initial cells of secretory resin cavities are protodermal and grow towards the mesophyll ground meristem; these cells then divide producing cell groups that are distinguished by the shape and arrangement of cytoplasm, and density. At the initial stages of differentiation of the secretory cavities, some central cells in these groups show dark cytoplasm and condensed nuclear chromatin. Later, there is cell wall loosening, tonoplast and plasmalemma rupture resulting in cell death. These cells, however, maintain organelle integrity until lysis, when the cell wall degrades and the plasmalemma ruptures, releasing protoplast residues, marked characteristics of programmed cell death. The secretory epithelium remains active until complete leaf expansion when the cavity is filled with resin and the secretory activity ceases. There are no wall residues between central cells in adult cavities. Our results demonstrate lysigeny and the importance of ontogenetic studies in determining the origin of secretory cavities.

Anatomy and ontogeny of the pericarp of Pterodon emarginatus Vogel (Fabaceae, Faboideae), with emphasis on secretory ducts

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The role of the parenchyma sheath and PCD during the development of oil cavities in Pterodon pubescens (Leguminosae-Papilionoideae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Developmental and structural features of secretory canals in root and shoot wood of Copaifera langsdorffii Desf. (Leguminosae-Caesalpinioideae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Functional aspects of floral nectar secretion of Ananas ananassoides, an ornithophilous bromeliad from the Brazilian savanna

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

OIL GLANDS IN PTERODON PUBESCENS BENTH. (LEGUMINOSAE-PAPILIONOIDEAE): DISTRIBUTION, STRUCTURE, and SECRETION MECHANISMS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Epididymis-specific pathologic disorders in rats exposed to gossypol from weaning through puberty

Previous work in our laboratory revealed that the pubertal period of reproductive development in the male rat was particularly vulnerable to gossypol exposure, with a higher frequency of round structures in the lumen of the cauda epididymidis in the treated rats. Herein, we utilized hemicastration and electron microscopy to confirm that the epididymis is a definitive target of gossypol. Although exposure to gossypol from weaning through puberty caused a significant decrease in daily sperm production, as well as in the concentration of sperm in the epididymis, serum testosterone levels and reproductive organ weights were not altered. In gossypol treated rats, sperm morphology was compromised severely, but the epithelium in testis and epididymis appeared morphologically normal. Ultrastructural examination revealed that round structures, present only in gossypol exposed males, represented: (1) principal cells exfoliated from the epididymal epithelium; (2) epididymal epithelial cell cytoplasm containing degenerating sperm; and (3) degenerating epithelial cells, consisting of vesicles and particles of different sizes, forms and densities. Taken together, the data confirm that gossypol targets the epididymis, disturbing both the structure and function of this organ, and presumably disrupts sperm maturation.

Dietary intervention with narrow-leaved cattail rhizome flour (Typha angustifolia L.) prevents intestinal inflammation in the trinitrobenzenesulphonic acid model of rat colitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Qualea grandiflora, a Brazilian Cerrado medicinal plant presents an important antiulcer activity

Qualea grandiflora is one of the species widely used in folk medicine to treat gastric ulcers in Cerrado of the central region of Brazil. The hydroalcoholic extract of bark (HE) of Qualea grandiflora was investigated for their ability to prevent and heal lesions in the gastric mucosa. The oral administration of HE exhibited antiulcer activity decreasing the ulcerative index induced by HCl/ethanol solution, indomethacin/bethanechol and stress. In the Shay model, results showed that HE (p.o.) only reduced the severity of gastric lesions without effects on pH, gastric acidity or volume. When given by intraduodenal route, HE changed the pH, but did not modify the other parameters of the gastric juice. These data were in accordance with those obtained when HE was administered orally for 14 days after gastric ulcers were induced by acetic acid in rats. HE presented healing process in subacute gastric ulcer induced by acetic acid in rats. Moreover, histological examinations showed the simple columnar epithelium, lamina propria with simple branched tubular glandules with dilated lumen and large amounts of mucus secretion. Phytochemical investigation of HE led to the detection of terpenes, steroids, saponins, phenolic compounds and tannins in this extract, which may be involved in the observed activity. (c) 2005 Elsevier B.V.. All rights reserved.

Discrimination of bile acids by the rainbow trout olfactory system: evidence as potential pheromone

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The antiulcer effect of Croton cajucara Benth in normoproteic and malnourished rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immunization protected well nourished mice but not undernourished ones from lung injury in Methicillin-resistant Staphylococcus aureus (MRSA) infection

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphological study of the hindgut in larvae of Anticarsia gemmatalis Hübner(Lepidoptera: Noctuidae)

A lagarta da soja (Anticarsia gemmatalis Hübner) tem grande interesse econômico, pois afeta significativamente a cultura da soja em todo o mundo. Este trabalho descreve a morfologia do intestino posterior de larvas de A. gemmatalis, com ênfase nos seus aspectos histológicos. O intestino posterior é constituído por regiões morfologicamente distintas, identificadas como piloro, íleo, cólon e reto. Independente da região, a parede do intestino posterior é constituída por fina cutícula, epitélio simples e camada muscular. A íntima cuticular apresenta espículas no anel intersticial posterior, entre o intestino médio e o posterior, e na região posterior do piloro. A musculatura do reto é formada por camada única de largas fibras circulares, diferindo das demais regiões do intestino posterior que apresentam duas camadas de fibras musculares. As extremidades distais dos túbulos de Malpighi atravessam as paredes do reto, constituindo o sistema criptonefridial característico de Lepidoptera.

A new vision of the origin and the oocyte development in the Ostariophysi applied to Gymnotus sylvius (Teleostei: Gymnotiformes)

Tendo por base os novos conhecimentos oriundos de recentes estudos com Perciformes marinho, a origem e o desenvolvimento dos oócitos no Ostariophysi Gymnotus sylvius são aqui descritos. da mesma maneira que ocorre nos Perciformes, em Gymnotus sylvius as oogônias são encontradas no epitélio germinativo que margeia as lamelas ovígeras. No início da foliculogênese, a proliferação das oogônias e sua entrada em meiose dão origem a ninhos de células germinativas que se projetam em direção ao estroma ovariano, a partir do epitélio germinativo. Os ninhos e o epitélio germinativo são suportados pela mesma membrana basal que os separa do estroma. Coincidindo com a paralisação da meiose os oócitos, presentes nos ninhos, são separados uns dos outros por processos citoplasmáticos das células pré-foliculares. As células pré-foliculares derivam do epitélio germinativo sendo, portanto, inicialmente células epiteliais. Durante a foliculogênese, ao mesmo tempo em que envolvem os oócitos individualizando-os, as células pré-foliculares sintetizam a membrana basal ao seu redor. Os oócitos entram em crescimento primário ainda dentro dos ninhos. Ao término da foliculogênese, o oócito e as células foliculares que compõem o folículo são circundados pela membrana basal. O folículo permanece conectado ao epitélio germinativo uma vez que ambos compartilham uma porção comum da membrana basal. Células oriundas do estroma circundam o folículo ovariano exceto na região de compartilhamento da membrana basal formando a teca. O folículo, a membrana basal e a teca formam o complexo folicular. O desenvolvimento do oócito ocorre dentro do complexo folicular e compreende os estágios de crescimento primário e secundário, maturação e ovulação. Os alvéolos corticais surgem no ooplasma momentos antes do início do crescimento secundário ou estágio vitelogênico que tem início com a deposição de vitelo, progride até o oócito esteja completamente desenvolvido e o ooplasma preenchido pelos glóbulos de vitelo. A maturação é caracterizada pela migração do núcleo ou vesícula germinativa, pela quebra da vesícula germinativa, ou seja, pela fragmentação do envoltório nuclear e, retomada da meiose. Na ovulação o ovo é liberado do complexo folicular para o lúmen ovariano. em comparação com os Perciformes marinhos com ovos pelágicos, o desenvolvimento oocitário em Gymnotus sylvius tem menos etapas dentro dos estágios de desenvolvimento, sendo as duas mais notáveis delas as ausências da formação das gotas de lipídio durante os crescimentos primário e secundário (e a consequente fusão das gotas para formar um único glóbulo de lipídio durante a maturação) e, a hidrólise do vitelo antecedendo a ovulação.