Vesicular Secretions Research Articles

Differential translational regulation of host exosomal proteins play key role in immunomodulation in antimony resistance in Visceral Leishmaniasis: A proteomic profiling study

In host-pathogen interactions, exosomal secretions are crucial for cell to cell communication and have an established role in immunomodulation. Protozoans, including Leishmania, modulates their host vesicular secretions for better survival; although the role of exosomal secretions in unresponsive against sodium antimony gluconate (SAG) has never been documented. In this study, the exosomal proteome of RAW macrophages infected with either SAG responsive (SAGS) or SAG unresponsive (SAGR) L. donovani parasites has been compared with uninfected RAW macrophages. Proteins isolated from exosomes were labelled with iTRAQ reagents; followed by subsequent LC-TOF/-MS analysis. In total, 394 proteins (p < 0.05) were identified which were shared common among all sets. Highly differentially expressed proteins were sorted by log2 value -1 and +1 as down regulated and up regulated respectively which yielded 58 proteins in SAGR and 41 proteins during SAGS infection. Out of the 58 proteins identified during SAGR infection, 17 proteins were of immune modulatory function. Network visualization model and pathway analysis revealed the interactions among these proteins via different immunological pathways with reported involvement of some proteins in SAG resistance and host immune modulation. Hence, the differential abundance of immune pathway related proteins in exosomes of infected host during SAGR infection supports the immune modulatory strategy adopted by SAG resistant parasites for enhanced survival .

Anatomy and Physiology of Animal Model Rats in Biomedical Research

A distinguishing feature of rodents, including rats, is the absence of canines and thepresence of prominent incisors. Rats are monophydontic, meaning they grow one setof teeth in their lifetime. The enamel of the rodent incisor contains iron, which givesit its yellow-orange color. Rats are mammals and as such, possess many similaritieswith other mammals. Only the peculiarities of the rat’s anatomy are addressed. Malerats reach puberty at 40 - 60 days of age. Descent of the testes usually occursbetween days 30 - 60. Sperm counts vary by strain. The male rat has an os penis.Male rats have the following accessory sexual organs: ampulla, seminal vesicles,prostate, bulbourethral glands, coagulating glands, and preputial glands. Thecoagulating gland and prostatic and vesicular secretions are responsible for thecopulation plug, a firm plug deposited in the vagina of the female after copulation.(This plug, when found outside the female rat, is capsuleshaped and approximately5 mm long.) The male rat has no nipples. The adult male rat has a prominentscrotum and a longer anogenital distance than the female rat.

The physiological roles of the boar ejaculate

During ejaculation in the boar, sperm cohorts emitted in epididymal cauda fluid are sequentially exposed and resuspended in different mixtures of accessory sex gland secretion. This paper reviews the relevance of such unevenly composed fractions of seminal plasma (SP) in vivo on sperm transport and sperm function and how this knowledge could benefit boar semen processing for artificial insemination (Al). The firstly ejaculated spermatozoa (first 10 ml of the sperm-rich fraction, SRF [Pl]) remain mainly exposed to epididymal cauda fluid and its specific proteins i.e. various lipocalins, including the fertility-related prostaglandin D synthase; than to prostatic and initial vesicular gland secretions. Plspermatozoa are hence exposed to less bicarbonate, zinc or fructose and mainly to PSP-I spermadhesin; than if they were in the rest of the SRF and the post-SRF (P2). Since the Pl-SP is less destabilizing for sperm membrane and chromatin, Pl-spermatozoa sustain most in vitro procedures, including cryopreservation, the best. Moreover, ejaculated firstly, the Pl-spermatozoa seem also those deposited by the boar as a vanguard cohort, thus becoming overrepresented in the oviductal sperm reservoir (SR). This vanguard SR-entry occurs before the endometrial signalling of SP components (as PSP-I/PSP-11 and cytokines) causes a massive influx of the innate defensive PMNs to cleanse the uterus from eventual pathogens, superfluous spermatozoa and the allogeneic SP. The SP also conditions the mucosal immunity of the female genital tract, to tolerate the SR-spermatozoa and the semi-allogeneic conceptus. These in vivo gathered data can be extrapolated into procedures for handling boar spermatozoa in vitro for Al and other biotechnologies, including simplified cryopreservation.

Mechanics of post-fusion exocytotic vesicle

Exocytosis is an important cellular process controlled by metabolic signaling. It involves vesicle fusion to the plasma membrane, followed by the opening of a fusion pore, and the subsequent release of the vesicular lumen content into the extracellular space. While most modeling efforts focus on the events leading to membrane fusion, how the vesicular membrane remodels after fusing to plasma membrane remains unclear. This latter event dictates the nature and the efficiency of exocytotic vesicular secretions, and is thus critical for exocytotic function. We provide a generic membrane mechanical model to systematically study the fate of post-fusion vesicles. We show that while membrane stiffness favors full-collapse vesicle fusion into the plasma membrane, the intravesicular pressure swells the vesicle and causes the fusion pore to shrink. Dimensions of the vesicle and its associated fusion pore further modulate this mechanical antagonism. We systematically define the mechanical conditions that account for the full spectrum of the observed vesicular secretion modes. Our model therefore can serve as a unified theoretical framework that sheds light on the elaborate control mechanism of exocytosis.

Ultrastructure of the male accessory glands of sesarmid crab, Parasesarma plicatum (Latreille, 1803)

The structure of accessory glands (AGs) in the male sesarmid crab, Parasesarma plicatum, is described by light and transmission electron microscopy. Adult males of carapace of width 1.6–2.2cm were collected from along the estuarine regions of Kanyakumari District, India. Posteriorly, the male reproductive system receives several sac-like structures, referred to as AGs. Histologically, the AG is internally lined by cuboidal epithelium and the lumen encloses eosinophilic vesicular secretions, apparently glycopreoteinaceous in nature. Ultrastructurally, the epithelium shows the signs of typical infrastructure for synthetic activity, as demonstrated by the prolific presence of rough endoplasmic reticulum, free ribosomes, and Golgi complex. The cytoplasm is manifested with electron-dense, electron-lucent, and medium-density secretory vesicles, and the mode of release into the lumen is both merocrine and apocrine. Within the lumen, these secretory vesicles coalesce and aggregate into large heterogeneous masses of varying sizes, which may play an important role post-copulation within the female duct.

The Extracellular Vesicles of the Helminth Pathogen, Fasciola hepatica: Biogenesis Pathways and Cargo Molecules Involved in Parasite Pathogenesis*

Extracellular vesicles (EVs) released by parasites have important roles in establishing and maintaining infection. Analysis of the soluble and vesicular secretions of adult Fasciola hepatica has established a definitive characterization of the total secretome of this zoonotic parasite. Fasciola secretes at least two subpopulations of EVs that differ according to size, cargo molecules and site of release from the parasite. The larger EVs are released from the specialized cells that line the parasite gastrodermus and contain the zymogen of the 37 kDa cathepsin L peptidase that performs a digestive function. The smaller exosome-like vesicle population originate from multivesicular bodies within the tegumental syncytium and carry many previously described immunomodulatory molecules that could be delivered into host cells. By integrating our proteomics data with recently available transcriptomic data sets we have detailed the pathways involved with EV biogenesis in F. hepatica and propose that the small exosome biogenesis occurs via ESCRT-dependent MVB formation in the tegumental syncytium before being shed from the apical plasma membrane. Furthermore, we found that the molecular “machinery” required for EV biogenesis is constitutively expressed across the intramammalian development stages of the parasite. By contrast, the cargo molecules packaged within the EVs are developmentally regulated, most likely to facilitate the parasites migration through host tissue and to counteract host immune attack.

Morphology of the reproductive tract and acquisition of sexual maturity in males of Potamotrygon magdalenae (Elasmobranchii: Potamotrygonidae).

The purpose of this study was to describe the structure of the reproductive tract of males of Potamotrygon magdalenae before, during, and after they acquire sexual maturity, and to establish the first maturity scale for males within the family Potamotrygonidae. The male reproductive tract of P. magdalenae is composed of testes, efferent ducts, epididymides, deferent ducts, seminal vesicles, Leydig, alkaline, and clasper glands, and claspers, all of which are paired and functional. Four sexual maturity stages were established: immature, maturing, reproductively active, and resting. The degree of claspers calcification is also a good indicator of sexual maturity in this species. The testes are lobulated, each lobe contains numerous spermatocysts which are organized in zones and are displaced radially from germinal papillae to the spermatozoa zone where individual spermatozoa are conveyed to the efferent ducts. The epididymis can be regionalized in head, body, and tail; these regions are distinguished by external pigmentation and by the epithelium lining configuration. The tail of the epididymis is connected with the deferent duct and this, in turn, with the seminal vesicle. The spermatozoa are organized in spermatozeugmata which begin to form in the deferent duct; this latter organ is attached laterally at the Leydig gland that is composed by simple glandular units. Irregular and vesicular secretions can be found in the genital ducts. These secretions might be associated with the maturation of the spermatozoa and formation of spermatozeugmata. The male reproductive tract of P. magdalenae is similar to other elasmobranchs; however, two types of primary spermatogonia, an epididymis internally regionalized, and the presence and structure of spermatozeugmata are specific features not yet described in freshwater stingrays. Most of the year, the males were reproductively active, however, few resting adult males occurred during one of the months of the lowest waters.

Comparison of unitary exocytic events in pituitary lactotrophs and in astrocytes: modeling the discrete open fusion-pore states

In regulated exocytosis the merger between the vesicle and the plasma membranes leads to the formation of an aqueous channel (a fusion-pore), through which vesicular secretions exit into the extracellular space. A fusion pore was thought to be a short-lived intermediate preceding full-fusion of the vesicle and the plasma membranes (full-fusion exocytosis). However, transient exocytic events were also observed, where the fusion-pore opens and closes, repetitively. Here we asked whether there are different discrete states of the open fusion-pore. Unitary exocytic events were recorded by the high-resolution cell-attached patch-clamp method in pituitary lactotrophs and brain astrocytes. We monitored reversible unitary exocytic events, characterized by an on-step, which is followed by an off-step in membrane capacitance (Cm), a parameter linearly related to the membrane area. The results revealed three categories of reversible exocytic events (transient fusion-pore openings), which do not end with the complete integration of the vesicle membrane into the plasma membrane. These were categorized according to the observed differences in the amplitude and sign of the change in the real (Re) parts of the admittance signals: in case I events (Re ≈ 0) fusion pores are relatively wide; in case II (Re > 0) and case III (Re < 0) events fusion pores are relatively narrow. We show that case III events are more likely to occur for small vesicles, whereas, case II events are more likely to occur for larger vesicles. Case III events were considerably more frequent in astrocytes than in lactotrophs.

The Evaluation of Free-L-Carnitine, Zinc and Fructose in the Seminal Plasma of Patients with Varicocele and Normozoospermia/Auswertung von freiem L-Carnitin, Zinc und Fructose im Spermaplasma von Männern mit einer Varikocele und Normozoospermie

The function of the epididymis and of the sex accessory glands have been investigated in a selected group of varicocele patients with normal sperm count. In the seminal plasma of these patients free-L-carnitine, fructose and zinc levels were determined as functional markers respectively of epididymis, seminal vesicles and prostate. Despite the unvaried free-L-carnitine and fructose levels, zinc levels were significantly lower (p less than 0.001) than in the control group. The Zn/F ratio, an index of the ratio between the prostatic and vesicular secretions, resulted also lower (p less than 0.01) with respect to the controls. The authors suggest that the impaired prostatic function could arise from the decreased venous drainage in the vesico-prostatic plexus. In the same patients sperm motility resulted significantly lower than in the controls, and was positively related to zinc levels (r = 0.44, p less than 0.01) and, to a higher degree, to the Zn/F ratio (r = 0.62, p less than 0.001). Our data show that in this selected group of varicocele patients with a not yet altered tubular epididymal unit, sex accessory gland secretions can influence, per se, the motility of the ejaculated spermatozoa.

Specialization of the Urinary Bladder in Two Pseudoplesiopines (Teleostei: Pseudochromidae)

Abstract Two pseudoplesiopine species, Pseudoplesiops rosae and Pseudoplesiops howensis, were found to possess a highly specialized urinary bladder. The urinary bladder was so-identified by tracking the opisthonephric ducts from the trunk kidney to their termination within the bladder lumen. The specializations included a pronounced thickening of the bladder wall, an elaboration of the internal surface area by means of extensive septal intrusions, and the frequent presence of vesicular or colloidal secretions within the bladder lumen. The extensive septal intrusions as well as the inner wall of the bladder lumen were lined by a conspicuous tall columnar epithelium. The epithelium and septa were most prominent in fish having no or only small amounts of accumulated lumenal secretions. In other fish having large amounts of stored lumenal secretions, the septa and septal epithelia were reduced or absent, suggesting a holocrine form of secretion. The tall columnar epithelium in the bladder consisted of cells h...

The role of the seminal vesicles and coagulating glands in fertilization in the rat.

To investigate the role of the seminal vesicles (SV) and coagulating glands (CG) in fertilization in the rat, partial resections of the SV (25%--group B), 50%--group C, and 75%--group D) or bilateral resection of the SV alone (100%--group E), or together with the CG (group F) were undertaken. In other groups, bilateral resection of the CG only (group G), or bilateral resection of the CG with ipsilateral SV resection (group H) were performed. A group of sham-operated rats served as controls (group A). There were no significant differences among groups A, B, C and D in the number of fertile rats post-operatively but significant differences were evident in groups E, F, G, H when compared with the control group (P less than 0.01 for all groups). Only the fertile rats were able to form copulatory plugs (CP) post-operatively. Bilateral ligation of the SV ducts was performed in ten fertile rats. Post-operatively, the proportion of fertile rats was decreased significantly (P less than 0.01). Removal of the ligatures resulted in a significant increase (P less than 0.01) in fertility. It was also demonstrated that the addition of rat seminal vesicular secretions (SVS) to epididymal sperm suspensions resulted in a significant decrease (P less than 0.001) in sperm motility. These results suggest that the SV and CG are necessary for fertility in rats, and that one role of SVS is the formation of a CP and not the maintenance of sperm motility.

Mechanisms of development of the dome in the semicircular canals of birds. II. Cellular reorganization

A light microscopic study of the epithelia of the crista ampullaris of the semicircular canals of the embryonic chicken indicates that the epithelial cells undergo irregular degenerative changes, with continual mitotic replacement of surface cells. The cupula develops over the surface epithelia through vesicular secretions containing acidophils fibrillar material mixed with globular formations derived from fragmentation of the surface epithelial cells. Electron microscopic studies demonstrate the mode of secretion of rounded or oval supraepithelial bodies from surface epithelium, contributing to the development of the cupula ampullaris. These observations provide evidence of cytoplasmic contributions of surface epithelial cells of the crista ampullaris contributing to the development and continued reorganization of the cupula ampullaris during embryonic development.

Zinc in human semen.

Seminal zinc was measured in normospermic and infertile patients by a new colorimetric method. Analysis of semen from 5 patients with bilateral agenesis of the vas deferens showed high levels of zinc (mean value 1411.2 micrograms/ml). Lower levels were found in 6 patients with monolateral congenital or acquired obstruction (695.2 micrograms/ml). The seminal zinc level in 6 patients who had had a vasectomy or who had an epididymal blockage (125.7 micrograms/ml) was approximately the same as in 41 controls (134.6 +/- 42 +/- SD). Zinc levels were reduced in hypogonadal patients. These data suggest that zinc is secreted mainly by the prostate, while vesicular, epididymal and testicular secretions are devoid of zinc. Evaluation of this metal therefore permits the diagnosis of patency of the seminal pathways, but does not permit identification of prostatitis. No correlation was found between sperm count or motility and the seminal zinc level, nor between the latter and varicocele.

Regulatory Features of Seminal Vesicle Development and Function

This chapter discusses the regulatory features of seminal vesicle development and function. Seminal vesicles or vesicular glands are a special type of secretory organ of the male genital tracts in many but not all mammalian species. These structures differentiate in the fetus from the caudal portion of the Wolffian ducts. The Wolffian duct also serves as the embryonic precursor of the epididymis, the ductus deferens, and, in certain mammals, of the secretory enlargements of the caudal terminus of the vas deferens known as the ampullary glands. Vesicular secretions exhibit great species variations in their chemical compositio, and contain high concentrations of substances that are present in only much smaller amounts in all other body fluids. The fetal morphogenesis of seminal vesicles and their growth and functional differentiation at puberty are strictly controlled by androgens, and are influenced by several other hormones. Testosterone secreted by testicular Leydig cells is the prime hormonal regulator of the fetal morphogenesis of seminal vesicles, of the growth and functional differentiation of these organs at puberty and the maintenance of their adult dimensions and secretory activities.

Calcium fractions in seminal plasma and functional properties of human spermatozoa.

The concentration of ionized calcium [Ca++] was reproducibly determined in human seminal plasma with a calcium sensitive electrode (Orion Space Stat 20). Dilution of the seminal plasma gave a linear decrease in free calcium concentration. Freezing and thawning or storage of the seminal plasma under anaerobic conditions did not influence the level of ionized calcium. Storage under aerobic conditions gave a temperature dependent decrease in CA++ which parallelled a spontaneous increase in pH. The mean concentration of ionized calcium (measured after a standardized air exposition) was 0.17 mM +/- 0.05 (SD) (range 0.09-0.29 mM). The Ca++ level was not correlated to the total calcium concentration or to markers for prostatic (zinc) or seminal vesicular (fructose) secretions. There were, however, more motile spermatozoa in semen samples with an ionized calcium level less than the average (0.17 mM) than in semen samples with a higher Ca++ level (53.8% +/- 8.4, N = 17 vs 45.0% +/- 12.8, N = 15, respectively, p less than 0.05). The percentage live spermatozoa was also higher (62.4% +/- 10.4, N = 17 vs 50.7% +/- 14.2, N = 15, p less than 0.01) in the semen samples with a low [Ca++]. Spermatozoa in the low [Ca++] group did also exhibit a better progressive motility than spermatozoa in the high [Ca++] group (p less than 0.05). It is suggested that the low level of ionized calcium in seminal plasma is of importance for motility of human spermatozoa and that the transfere of spermatozoa from a high Ca++ in the epididymis to the low levels in accessory sex glands secretion might be of significans for activation of spermatozoa upon ejaculation.

Rôle du plasma séminal dans la survie in vitro des spermatozoïdes de bouc

The in vitro survival of ejaculated and epididymal goat sperm was measured in a milk diluent while being incubated at + 37 degrees C and after having been exposed to seminal plasma or to its components. Non-breeding season seminal plasma had a negative effect on sperm survival whether the cells were cooled to + 20 degrees C, chilled to + 4 degrees C or deep-frozen (- 196 degrees C) before being incubated at + 37 degrees C. Bulbo-urethral gland secretions also had a deleterious effect on the survival of washed ejaculated and epididymal sperm cooled to + 20 degrees C. The deleterious effect of the bulbo-urethral secretions on sperm survival and motility was significantly inhibited by the vesicular secretions. Non-breeding season seminal plasma contained bulbo-urethral but little or no vesicular secretions. The non-inhibition of their negative effect(s) may explain that of non-breeding season seminal plasma. Breeding season and non-breeding season washed ejaculated sperm had a better survival and a better motility than those incubated with breeding season seminal plasma. The mild washing procedure used may be responsible for the incomplete removal of seminal plasma from the sperm environment, namely that of the negative factors of the bulbo-urethral secretions. Breeding season seminal plasma would thus simply inhibit the effect of these negative factors or the factors themselves. This hypothesis is supported by the fact that breeding season seminal plasma had no effect on the survival of epididymal sperm.

Passage of chemicals into human and animal semen: mechanisms and significance.

This review will begin with a brief account of the secretory mechanisms operating in the male reproductive tract. The entry of the different chemicals will be dealt with; with separate reference to testicular fluids, epididymal plasma, prostatic and vesicular secretions, and whole semen. Examples will be given of a number of chemical substances capable of passing into the secretions of the male reproductive tract and semen, in man and in animals--antispermatogenic and antiandrogenic agents, industrial chemicals, chemotherapeutic drugs, food additives, etc. The review will end with a critical appraisal of the methods involved and the results obtained from analyses of various chemicals in semen.

Anaerobic and aerobic bacteria in secretions of prostate and seminal vesicles of infertile men.

A cytological and bacteriological study was made of prostatic (EPS) and vesicular (EVS) secretions from 123 infertile men who were suspected of having chronic genital tract inflammation and from 31 men with premature ejaculation (1,12,16). In the microbiological investigations samples were inoculated within 10 min on various culture media and incubated under both aerobic and anaerobic conditions. Bacterial loads of more than 10,000 colony-forming units of a single species or genus per milliliter of EPS or EVS were considered to be pathological. In the infertile subjects with proven inflammation of the seminal accessory glands, the EPS and the EVS that gave positive cultures and had bacterial loads defined as pathological contained large numbers of anaerobic or microaerophilic organisms (EPS: 51 of the 63 bacterial strains found, congruent to 81%; EVS: 19 of the 20 bacterial strains found, congruent to 95%).

Urethral discharge, constipation, and hemorrhoids New syndrome with report of 7 cases

A new syndrome in which 7 cases share common clinical features of urethral discharge only at defecation, constipation, and hemorrhoids is reported. The discharge occurred only with constipation. The relationship between urethral discharge, constipation, and hemorrhoids is discussed. The concept that hemorrhoids lead to prostatic venous congestion is put forward. The urethral discharge at defecation seems to be the result of “milking” of the congested prostate by the hard stools. The mechanism of fecal and urinary “milking” of the prostate is discussed. The role of the congested prostate in infertilogenesis is presented. It seems that metabolic accumulation in the prostatic, vesicular, and ampullary secretions affected the spermatogenic activity as it similarly does in varicocele. Permanent disappearance of urethral discharge and improvement of semen quality were achieved on anoprostatic decongestion by medical treatment, hemorrhoid injection, or hemorrhoidectomy. The syndrome of prostatorrhea, constipation, and hemorrhoids should be considered in patients with idiopathic urethral discharge and in infertile patients.

Determination of fructose by the zirconyl chloride reaction

The specifie reaction of ketoses with zirconyl chloride was used to develop a method for the determination of fructose in vesicular secretions, seminal plasma, and blood plasma. After deproteinization with 96% ethanol, the samples can be stored at 4°C until further processing. The supernatant is incubated with zirconyl chloride at 100°C for 30 min. Measurements are made of the absorbance and/or fluorescence. The absorbance is measured at 334 nm, and the fluorescence at an excitation wavelength of 355 nm and an emission wavelength of 410 nm. With an aqueous solution containing 40 mmol/liter of zirconyl chloride, the reaction was linear in the fructose concentration range of 0–8 mmol/liter. The reaction product is stable for at least 60 min.