Tergal glands in termite soldiers of the subfamily Syntermitinae (Isoptera: Termitidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Biochemical and cytochemical studies of the enzymatic activity of the venom glands of workers of honey bee Apis mellifera L. (Hymenoptera, Apidae)

Biochemical studies revealed that the activity of some hydrolytic enzymes from the venom glands of honey bee Apis mellifera was higher in workers of 14 days of age than in those of 40 days. Among these enzymes, the highest activity was recorded for acid phosphatase, which was cytochemically detected throughout the length of the secretory filament and surrounding the canaliculi of the distal region of the reservoir. The acid phosphatase was considered to be a typical secretion product, since it was present in the cytoplasm as well as in the canaliculi of the secretory cells. (c) 2009 Elsevier Ltd. All rights reserved.

Cephalic salivary gland ultrastructure of worker and queen eusocial bees (Hymenoptera, Apidae)

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

Ultrastructural studies of the mandibular gland of Melipona quadrifasciata Lepeletier, 1836 (Apidae, Meliponini): a comparison between workers and queens

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

Mandibular glands in reproductives of asian termite coptotermes gestroi (Isoptera: Rhinotermitidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fine structure of Mytella falcata (Bivalvia) gill filaments

Bivalve filter feeders are sessile animals that live in constant contact with water and its pollutants. Their gill is an organ highly exposed to these conditions due to its large surface and its involvement in gas exchanges and feeding. The bivalve Mytella falcata is found in estuaries of Latin America, on the Atlantic as well as the Pacific Coast. It is commonly consumed, and sometimes is the only source of protein of low-income communities. In this study, gill filaments of M. falcata were characterized using histology, histochemistry and transmission electron microscopy for future comparative studies among animals exposed to environmental pollutants. Gill filaments may be divided into abfrontal, intermediate and frontal zones. Filaments are interconnected by ciliary discs. In the center of filaments, haemocytes circulate through a haemolymph vessel internally lined by an endothelium and supported by an acellular connective tissue rich in polysaccharides and collagen. The abfrontal zone contains cuboidal cells, while the intermediate zone consists of a simple squamous epithelium. The frontal zone is composed of five columnar cell types: one absorptive, mainly characterized by the presence of pinocytic vesicles in the apical region of the cell; one secretory, rarely observed and three ciliated with abundant mitochondria. All cells lining the filament exhibit numerous microvilli and seem to absorb substances from the environment. PAS staining was observed in mucous cells in the frontal and abfrontal zones. Bromophenol blue allowed the distinction of haemocytes and detection of a glycoprotein secretion in the secretory cells of the frontal region. The characteristics of M. falcata gill filaments observed in this study were very similar to those of other bivalves, especially other Mytilidae, and are suitable for histopathological studies on the effect of water-soluble pollutants. (C) 2007 Elsevier Ltd. All rights reserved.

Silk formation mechanisms in the larval salivary glands of Apis mellifera (Hymenoptera : Apidae)

The mechanism of silk formation in Apis mellifera salivary glands, during the 5th instar, was studied. Larval salivary glands were dissected and prepared for light and polarized light microscopy, as well as for scanning and transmission electron microscopy. The results showed that silk formation starts at the middle of the 5th instar and finishes at the end of the same instar. This process begins in the distal secretory portion of the gland, going towards the proximal secretory portion; and from the periphery to the center of the gland lumen. The silk proteins are released from the secretory cells as a homogeneous substance that polymerizes in the lumen to form compact birefringent tactoids. Secondly, the water absorption from the lumen secretion, carried out by secretory and duct cells, promotes aggregation of the tactoids that form a spiral-shape filament with a zigzag pattern. This pattern is also the results of the silk compression in the gland lumen and represents a high concentration of macromolecularly well-oriented silk proteins.

Ultrastructural aspects of the mandibular gland of Melipona bicolor Lepeletier, 1836 (Hymenoptera : Apidae, Meliponini) in the castes

The mandibular gland in Melipona bicolor workers and queens was studied by scanning and transmission electron microscopy. There is no difference in the gland anatomy between the castes, but the transmission electron microscopy showed variation of the cellular ultrastructure according to the secretory phase of the gland in both castes. Smooth endoplasmic reticulum was abundant in the secretory cells of physogastric queens, indicating that these cells produce lipid secretion that is stored in granules with multi-lamellar bodies. Mitochondrial variations during the cell secretory cycle indicates their participation in the lipid synthesis. After secretion, release in the reservoir lumen through the collecting canals, the secretory cells contain many myelinic bodies, indicative of cellular regression. (C) 2004 Elsevier Ltd. All rights reserved.

Ultrastructure of the intramandibular gland of workers and queens of the stingless bee, Melipona quadrifasciata

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

Morphophysiological Differences between the Metapleural Glands of Fungus-Growing and Non-Fungus-Growing Ants (Hymenoptera, Formicidae)

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

Structure, histochemistry, and ultrastructure of the epithelium and stroma in the gerbil (Meriones unguiculatus) female prostate

The female prostate has aroused scientific interest because it is subjected to the same diseases compromising the male prostate during aging. The objective of this work was to characterize structurally, cytochemically, and ultrastructurally the tissue compartments of the normal adult female prostate of Meriones unguiculatus gerbils. The morphological analyses showed that the gerbil's female prostate is constituted of a cluster of glands and ducts inserted in a musculofibrous stroma. The alveolar epithelium is differentiated and consisted of basal proliferating cells, intermediary cells, and secretory cells. The secretory cells are the most numerous cell type and continuously secrete glycoproteins. The basal cells are the source of the secretory cells and they are then responsible for the alveolus renovation. The prostatic stroma is abundant and rich in elastic and collagen fibers, which are closely associated with smooth muscle cells and fibroblasts. The results showed that the gerbil's female prostate shows morphological and ultrastructural homology to the human female prostate (Skene's gland), and despite being a small organ, it is a mature and physiologically active gland. (C) 2003 Elsevier Ltd. All rights reserved.

Biological behavior of the gerbil ventral prostate in three phases of postnatal development

In this study, we characterized the gerbil's ventral prostate histology ultrastructurally and quantitatively throughout three phases of postnatal development (young, adult, and old) in order to comprehend its biological behavior and propensity to developing spontaneous lesions with aging. The gerbil prostate is composed of alveoli and ducts immersed in a stroma composed of smooth muscle, fibroblasts, collagen and elastic fibers and vessels. The prostate tissue components present morphological and quantitative aspects that vary according to age. Young animals have an immature gland with modest secretory activity. Synthetic activity remained stable in adult and old gerbil. However, prostatic morphology was altered in the aging, showing an increased epithelium and stromal fibrosis. The nuclei of the secretory cells increased with aging, whereas nucleoli presented few alterations during postnatal development. The epithelial proliferation and stromal remodeling noted in this study indicate that the gerbil prostate may respond to the androgen declines typical of senescence through epithelial proliferation and stromal remodeling.

Tissue alterations in the Guinea pig lateral prostate following antiandrogen flutamide therapy

The flutamide antiandrogenic effects oil the Guinea pig male prostate morphology in puberal, post-puberal and adult ages were evaluated in the present study. Daily-treated group animals received flutamide Subcutaneous injection at a dose of 10 mg/Kg body weight for 10 days. The control group animals received a pharmacological vehicle under the same conditions. The lateral prostate was removed, fixed and processed for light and transmission electron microscopy. The results revealed all increase of the acinus diameter in the treated puberal animals and straitness in the stromal compartment around the acini. The epithelial cells exhibited cubic phenotype. In the post-puberal and adult animals, a decrease of the acinus diameter was observed, as well as an increase of the smooth muscle layer and presence of the folds at epithelium. The ultrastructural evaluation of the secretory cells in the treated group demonstrated endomembrane enlargement, mainly in the rough endoplasmic reticulum and Golgi apparatus. In addition, a decrease of the microvilli and alterations in the distribution patterns and density of the stromal fibrillar components were observed. In Conclusion, the flutamide treatment exerts tissue effects oil the lateral prostate, promoting stroma/epithelium alterations.

Lobe identity in the Mongolian gerbil prostatic complex: A new rodent model for prostate study

Knowledge of structural and physiological differences among the prostatic lobes (PL) is the basis for development of experimental studies in traditional laboratory rodents. Although Mongolian gerbil reproductive organs have been increasingly investigated, its prostate structure is far from being properly known, and investigations of this organ focused on the ventral lobe (VL). Thus, the present study provides a thorough morphological description of prostatic complex in the male adult gerbil on the basis of topographic, histological, and ultrastructural analysis and ductal branching. Like other rodents, four pairs of PL were observed. However, in contrast to the rat and mouse, the VL is the least voluminous component and the dorsolateral lobe (DLL) is the most prominent and spatially isolated from remaining PL. The occurrence of a dorsal lobe (DL), hidden between bladder and insertion of seminal vesicles, has not been mentioned in previous reports with Mongolian gerbil. Collagenase digestion followed by microdissection revealed that, except for DL, which has a tubularacinar organization, all PL exhibit tubular organization and variable ductal branching. Distinct histological and ultrastructural features such as secretory epithelium, aspect of luminal secretion and stromal organization are reported for each PL and are confirmed by morphometric and stereological methods. Histological sections showed at least three intralobar segments in VL and DL. Ultrastructural analysis evidenced that, although luminal epithelial cells of PL share typical features of exocrine secretory cells, there are striking lobe phenotypical variations. Both merocrine and apocrine pathways are observed in variable rates in all PL, with the predominance of the former in the DLL and the latter in the CG. The morphological observations presented herein point to distinct structural identities for each PL, which probably reflects,specific functional compromise of seminal fluid secretion. These data also point to the gerbil as a good model for investigations concerning the regulation of prostate development and homeostasis, mainly with regard to the dorsal and dorsolateral PL.

Morphology of Richards' Gland in the Wasp Metapolybia docilis

Richards gland in the epiponine wasp Metapolybia docilis occurs at the anterior side of the 5(th) abdominal sternite, and is formed by approx. 360 secretory cells. The cells discharge their secretory products through accompanying duct cells into a reservoir that is formed by the invaginated intersegmental membrane between the 4(th) and 5(th) sternites. The ultrastructural characteristics of the secretory cells are indicative for the production of a non-proteinaceous secretion, which is in line with the trail substance that is used by these wasps during their swarm-founding.