New observations on the innervation of striated ducts in submandibular glands of cats,including possible peptidergic nerves

Summary The presence of hypolemmal axons between striated duct cells in submandibular glands of cats has been established electron microscopically. Axons were found between light cells, between light and dark cells and between light and basal cells. Hypolemmal axons were observed most frequently in the junctional region between striated and intercalary ducts. They were often more common in younger animals. Dark cells with numerous processes sometimes appeared to have a special relationship with hypolemmal axons.Most of the hypolemmal axons in striated ducts contained characteristic agranular vesicles of the cholinergic type, about 40 nm in diameter; many of these axons also contained large dense cored vesicles of the peptidergic type, about 100 nm in diameter and possessing a more clear outer halo. No adrenergic axons have been observed beneath the basal lamina of striated ducts, even after use of 5-OHDA.The possibility that some of the hypolemmal axons in striated ducts are peptidergic and their possible functions are discussed. Apart from other activities these axons may have a role in supplying special trophic factors to the cells, helping them in their developmental specialisation and maintaining them in normal condition. An absence of such factors after parasympathetic decentralisation may be responsible for the dramatic atrophic changes in striated duct cells, especially since the atrophy in the gland is not solely due to an absence of acetylcholine activation.Supported by an M.R.C. GrantThis work has been helped by the technical assistance of Mr. P.S. Rowley     

Vegetative anatomy of Pachycortnus (Anacardiaceae)

Pachycormus discolor , an arborescent desert perennial endemic to Baja California, has small, pinnately compound, hypostomatic, bifacial leaves produced on short shoots and photosynthetic stem phelloderm covered by exfoliating translucent phellem. Tightly packed laminal palisade cells are filled with tannins and lack chloroplasts. Spongy mesophyll is the major photosynthetic tissue. Leaves possess unicellular trichomes with secondary walls and uniseriate trichomes with glandular heads. Schizogenous resin ducts occur in primary phloem of stems, leaves and roots as well as all living tissues of the bark. Developmental studies reveal that initiation and differentiation of foliar primordia resembles that of other dicotyledons except that tannin cells and secretory ducts arise precociously. Primary vasculature is an open sympodial system with three principal traces diverging toward each foliar primordium. The wood is highly specialized and comprises mostly unlignified cells packed with starch grains. Thick bark is mainly produced as annual layers of secondary phloem marked by a ring of secretory ducts each surrounded by tannin cells. The possible adaptive significance of these unusual anatomical features is discussed.     

Immunocytochemical localisation of some lysosomal hydrolases,their presence in luminal fluid and their directional secretion by human epididymal cells in culture

The way in which the human epididymis modifies spermatozoa during their sojourn in this structure might be clarified by knowledge of the nature of its secretions. We have examined the presence of several lysosomal hydrolases in human epididymal tissue and fluids, and their synthesis and secretion by monolayer cultures. Tissues were obtained from men undergoing orchidectomy for prostatic carcinoma. The enzymes cathepsin D and acid -glucosidase were localised in the lysosomes of epithelial cells from the corpus epididymidis, by an immunocytochemical technique. Cathepsin D was also found in epithelial cells of the efferent ducts within lysosomes, apical vesicles and multivesicular bodies. No immunolocalisation of acid glucosidase in the efferent ducts or on the microvilli of the corpus was demonstrable. Cathepsin D, -hexosaminidase (N-acetylglucosaminidase) and -glucosidase were measurable in the luminal fluid from the human corpus epididymidis; -hexosaminidase was secreted into the culture medium by confluent monolayers of epididymal and efferent duct cells. Immunoprecipitation of cell extracts and culture medium of these cultures incubated with ³⁵S-methionine revealed that the precursors of cathepsin D and -hexosaminidase were synthesized and secreted by such monolayers. Thus, active lytic enzymes are secreted by the human epididymis and could modify sperm membranes.     

果胶酶的细胞化学定位:马尾松树脂道发生的细胞化学证据

运用薄切片和电镜细胞化学方法观察了马尾松(Pinus massoniana Lamb.)茎皮层树脂道的发育及发育过程中果胶酶的变化.树脂道的发育过程一般可分为4个阶段,即原始细胞阶段、胞间隙形成阶段、腔道扩大阶段和树脂道成熟阶段.在原始细胞阶段,果胶酶的反应产物首先出现在原始细胞膨胀的细胞壁角隅处,然后沿细胞壁中层分布.胞间隙形成后,果胶酶的反应产物分布在细胞壁和胞间隙的交界面.随着胞间隙的扩大,反应产物的密度逐渐降低.当树脂道成熟后,上皮细胞壁上则没有果胶酶的反应产物出现.细胞化学证据表明:在树脂道的发育过程中,果胶酶降解树脂道原始细胞细胞壁中层,支持树脂道以裂生方式形成.果胶酶的细胞化学定位技术还可用于其他植物中与果胶水解有关的发育过程.     

Membrane Domain Specificity in the Spatial Distribution of Aquaporins 5, 7, 9, and 11 in Efferent Ducts and Epididymis of Rats

Water content within the epididymis of the male reproductive system is stringently regulated to promote sperm maturation. Several members of the aquaporin (AQP) family of water channel–forming integral membrane proteins have been identified in epididymal cells, but expression profiling for this epithelium is presently incomplete, and no AQP isoform has yet been identified on basolateral plasma membranes of these cells. In this study, we explored AQP expression by RT-PCR and light microscopy immunolocalizations using peroxidase and wide-field fluorescence techniques. The results indicate that several AQPs are coexpressed in the epididymis including AQP 5, 7, 9, and 11. Immunolocalizations suggested complex patterns in the spatial distribution of these AQPs. In principal cells, AQP 9 and 11 were present mainly on microvilli, whereas AQP 7 was localized primarily to lateral and then to basal plasma membranes in a region-specific manner. AQP 5 was also expressed regionally but was associated with membranes of endosomes. Additionally, AQPs were expressed by some but not all basal (AQP 7 and 11), clear (AQP 7 and 9), and halo (AQP 7 and 11) cells. These findings indicate unique associations of AQPs with specific membrane domains in a cell type– and region-specific manner within the epididymis of adult animals. (J Histochem Cytochem 56:1121–1135, 2008)     

Immunolocalization of aquaporins 1, 2 and 7 in rete testis, efferent ducts, epididymis and vas deferens of adult dog

The transepithelial movement of water into the male reproductive tract is an essential process for normal male fertility. Protein water channels, referred to as aquaporins (AQPs), are involved in increasing the osmotic permeability of membranes. This study has examined the expression of AQP1, AQP2, and AQP7 in epithelial cells in adult dog efferent ducts, epididymis, and vas deferens. Samples of dog male reproductive tract comprising fragments of the testis, initial segment, caput, corpus and cauda epididymidis, and vas deferens were investigated by immunohistochemistry and Western blotting procedures to show the localization and distribution of the AQPs. AQP1 was noted in rete testis, in efferent ducts, and in vessels in the intertubular space, suggesting that AQP1 participated in the absorption of the large amount of testicular fluid occurring characteristically in the efferent ducts. AQP2 expression was found in the rete testis, efferent ducts and epididymis, whereas AQP7 was expressed in the epithelium of the proximal regions of the epididymis and in the vas deferens. This is the first time that AQP2 and AQP7 have been observed in these regions of mammalian excurrent ducts, but their functional role in the dog male reproductive tract remains unknown. Investigations of AQP biology could be relevant for clinical studies of the male reproductive tract and to technologies for assisted procreation. R.F.D. gratefully acknowledges a Fellowship from the Department of Anatomy, Institute of Biosciences, UNESP, Botucatu, SP, Brazil. This work was also funded by FAPESP (Sao Paulo State Research Foundation; grant 04/05578–1 to A.M.O. and grant 04/05579–8 to R.F.D.). This paper is part of the PhD Thesis presented by R.F.D. to the State University of Campinas – UNICAMP, Brazil.     

Right-handed penises of the earwig Labidura riparia (Insecta, Dermaptera, Labiduridae): evolutionary relationships between structural and behavioral asymmetries

The number of penises vary in the insect suborder Forficulina (order Dermaptera; earwigs). Males of the families Diplatyidae, Pigidicranidae, Anisolabididae, Apachyidae, and Labiduridae have two penises (right and left), while those of the Spongipohridae, Chelisochidae, and Forficulidae have a single penis. The proposed phylogenetic relationships among these families suggest that the single‐penis families evolved from an ancestor possessing two penises. To date, examinations of double‐penis earwig species have found that only a single penis is used per single copulation. These diversities in structural and behavioral aspects of genitalia raises the following intriguing questions: How are the two penises used? Why did a penis degenerate in several earwig families, and which one was lost? To address these questions, structural and behavioral asymmetries were examined in detail for a representative species Labidura riparia (Labiduridae). Although there was no detectable morphological differentiation between the right and left penises, male L. riparia predominantly used the right one for insemination. This significant “right‐handedness” developed without any experience of mating and was also manifested in the resting postures of the two penises when not engaged in copulation. However, surgical ablation of the right penis did not influence the insemination capacity of males. In wild‐caught males, only about 10% were left‐handed; within this group, abnormalities were frequently observed in the right penis. These lines of evidence indicate that the left penis is merely a spare intromittent organ, which most L. riparia males are likely never to use. Additional observations of five species of single‐penis families revealed that the left penis degenerated in the common ancestor of this group. Considering the proposed sister relationship between the Labiduridae and the single‐penis families, it is possible that such behavioral asymmetries in penis' use, as observed in L. riparia, are parental to the evolutionary degeneration of the infrequently used left penis. J. Morphol., 2006. © 2006 Wiley‐Liss, Inc.     

Structure of the kidney in the coelacanth Latimeria chalumnae with reference to osmoregulation

The morphology of the nephrons of the coelacanth Latimeria chalumnae was investigated by light microscopy. Each nephron is composed of a large renal corpuscle with well‐vascularized glomerulus, non‐ciliated neck segment, proximal convoluted tubule divided into distinct first and second segments, non‐ciliated intermediate segment, distal tubule, collecting tubule and collecting duct. The parietal layer of the Bowman's capsule of the renal corpuscle is composed of low cuboidal cells. The short non‐ciliated neck segment is lined by cuboidal epithelium. The first and second proximal segments display a prominent brush border and contain amorphous material in their lumen. The second proximal segment differs from the first segment in having taller columnar epithelium and a relatively narrow lumen. The intermediate segment is lined by non‐ciliated columnar epithelium and its lumen appears empty. The distal tubule is narrow in diameter and its cuboidal epithelium is devoid of intercalated cells. A unique feature of L. chalumnae is having binucleate cells in the tubule and collecting duct epithelium. The renal arteries have poorly developed tunica media and its cells contain granular material. The structure of L. chalumnae nephrons correlates well with their osmoregulatory function and resembles those of euryhaline teleosts.     

Morphological changes in the efferent ducts during the main phases of the reproductive cycle of birds

The changes that take place in the efferent ducts during the major phases of the reproductive cycle of birds were studied morphologically using standard histological, morphometric, and ultrastructural methods in prepuberal, sexually mature and sexually active, and sexually mature but sexually inactive domestic fowl (Gallus domesticus), drake (Anas platyrhynchos), and guinea fowl (Numida meleagris). Profound structural and dimensional changes occurred in both segments (proximal and distal) of the efferent ducts and, in particular, in the nonciliated (Type I) cell of the proximal duct of sexually mature but inactive birds. The subapical tubulovacuolar system was markedly atrophic in nonciliated (Types I and II) cells and the numerous round dense globules of Type I cells that normally occurred in sexually active birds were replaced by fewer and more pleomorphic bodies containing lipofuscin granules in sexually resting birds. Lipid droplets, few and extremely large in inactive drakes but numerous and smaller in size in guinea fowls and domestic fowls, occurred in the Type I cell at both infra- and supranuclear levels of resting but not in prepuberal or sexually active birds. Ciliated cells in both segments of the ducts exhibited fewer and less profound phase-dependent changes ultrastructurally. Generally, the Type I cells of the proximal efferent duct appeared to be more sensitive to androgen deprivation than the Type II cell of the distal efferent duct or ciliated cells in both ducts. These morphologically phase-dependent features of the efferent ducts of birds may be used, together with or independent of testicular changes, in the determination of the status of the testis and epididymis of a male bird with regard to the reproductive cycle, especially in seasonally breeding species.