Causas e Tratamentos de Distúrbios Ejaculatórios em Garanhões / Causes and Treatments of Ejaculatory Disorders in Stallions

A ejaculação é um complexo processo de eventos neurofisiológicos sincronizados em coordenação com vários sistemas e órgãos. Antes do advento da injeção intracitoplasmática de espermatozoides (ICSI), a ejaculação era um passo absolutamente essencial na reprodução. Os distúrbios ejaculatórios por sua vez são caracterizados pela não ocorrência do processo ejaculatório, mesmo que todos os demais parâmetros relacionados ao comportamento sexual apresentem-se normais. As principais causas dessas falhas ou alterações na ejaculação estão relacionadas à sensibilidade dolorosa durante a cópula, ejaculação retrógrada, disfunção psicogênica, obstruções do aparelho reprodutor masculino, urospermia, oligospermia ou azoospermia, além de falhas na contração da musculatura lisa do trato genital ou alterações musculoesqueléticas e neurológicas. O tratamento é dependente da causa primária de cada alteração. O controle da dor, ajustes no manejo, aumento do estímulo antes da coleta associados a tratamentos farmacológicos que atuam nas sinapses neuromotoras penianas tendem a resolver os principais distúrbios ejaculatórios, levando-se em consideração que as respostas a estes tratamentos são variadas de acordo com a individualidade do garanhão com relação a doses, protocolos, vias de administração e combinações de fármacos.(AU)

Ejaculation is a complex process of neurophysiological events synchronized in coordination with various systems and organs. Before the advent of intracytoplasmic sperm injection (ICSI), ejaculation was an absolutely essential step in reproduction. Ejaculatory disorders, in turn, are characterized by the nonoccurrence of the ejaculatory process, even if all other parameters related to sexual behavior are normal. The main causes of these failures or changes in ejaculation are related to painful sensitivity during copulation, retrograde ejaculation, psychogenic dysfunction, obstructions of the male reproductive system, urospermia, oligospermia, azoospermia, in addition to failures in the contraction of the smooth muscles of the genital tract or musculoskeletal disorders and neurological. Treatment is dependent on the primary cause of each change. Pain control, management adjustments, increased stimulus before collection associated with pharmacological treatments that act on penile neuromotor synapses tend to resolve the main ejaculatory disorders, taking into account that the responses to these treatments vary according to the individuality of the stallion with regard to dosages, protocols, routes of administration and drug combinations.(AU)

Structure and ultrastructure of spermatozoa and spermiogenesis in three species of Lucilia Robineau-desvoidy, 1830 (Diptera: Calliphoridae).

Morphology of male internal reproductive organs, spermatozoa, and spermiogenesis of the blow-flies Lucilia cuprina, Lucilia eximia, and Lucilia peruviana is first described here, using light and transmission electron microscopy. Spermiogenesis follows the characteristics described for others insect species. The spermatozoa of L. cuprina are similar to those described for other Brachycera. However, in L. eximia and L. peruviana, some differences were found. In L. cuprina and L. eximia species, the spermatozoa are long and thin, measuring about 211 µm and 146 µm in length, of which the head region measures approximately 19 µm and 17 µm, respectively. A polymorphism was observed in L. cuprina and L. eximia spermatozoa. In all three species, the head includes a monolayered acrosome with electron-lucent material. The shape of the nucleus, in cross sections, varies from circular to oval with completely condensed chromatin. Implantation of the axoneme was observed in the middle region of the nucleus, known as the "peg" region. In the next region, the beginning of two mitochondrial derivatives of similar diameter and different lengths in L. cuprina and only one in L. eximia and L. peruviana was observed. In the overlap region, the following structures were observed: nucleus, centriolar adjunct, mitochondrial derivatives, and axoneme. The axoneme is of a conventional insectan type with a 9 + 9 + 2 microtubular arrangement. The male internal reproductive tract consists of testis, deferent ducts, a strongly developed seminal vesicle, accessory glands, and ejaculatory duct. These features are consistent with the structural diversity of the dipteran reproductive tract and spermatozoa, comprising an essential tool for understanding the complex variations found in the Diptera.

Surgical treatment of male infertility in the era of intracytoplasmic sperm injection - new insights.

Assisted reproductive technology is an evolving area, and several adjuvant procedures have been created to increase a couple's chance of conceiving. For male infertility, the current challenges are to properly accommodate old and new techniques that are both cost-effective and evidence-based. In this context, urologists are expected to diagnose, counsel, provide medical or surgical treatment whenever possible and/or correctly refer male patients for assisted conception. Urologists are sometimes part of a multiprofessional team in an assisted reproduction unit and are responsible for the above-cited tasks as well as the surgical retrieval of sperm from either the epididymides or testicles. We present a comprehensive review of the surgical treatment options for infertile males, including the perioperative planning and prognostic aspects, with an emphasis on the role of microsurgery in the optimization of treatment results. This review also discusses current techniques for sperm retrieval that are used in association with assisted reproductive technology and includes sperm retrieval success rates according to the technique and the type of azoospermia. New insights are provided with regard to each surgical treatment option in view of the availability of assisted conception to overcome male infertility.

In vivo treatments with fulvestrant and anastrozole differentially affect gene expression in the rat efferent ductules.

Estrogen plays a key role in maintaining the morphology and function of the efferent ductules. We previously demonstrated that the antiestrogen fulvestrant markedly affected gene expression in the rat efferent ductules. The mechanism of fulvestrant action to modulate gene expression may involve not only the blockade of ESR1 and ESR2 estrogen receptors, but also the activation of ESR1 and ESR2 when the receptors are tethered to AP-1 or SP1 transcription factors, or the activation of the G protein-coupled estrogen receptor 1. We therefore compared the effects of two strategies to interfere with estrogen action in the rat efferent ductules: treatment with fulvestrant or with the aromatase inhibitor anastrozole. Whereas fulvestrant markedly increased Mmp7 and Spp1, and reduced Nptx1 mRNA levels, no changes were observed with anastrozole. Fulvestrant caused changes in epithelial morphology that were not seen with anastrozole. Fulvestrant shifted MMP7 immunolocalization in the epithelial cells from the supranuclear to the apical region; this effect was less pronounced with anastrozole. In vitro studies of (35)S-methionine incorporation showed that protein release was increased, whereas tissue protein content in the efferent ductules of fulvestrant-treated rats was decreased. Although fulvestrant markedly affected gene expression, no changes were observed on AP-1 and SP1 DNA-binding activity. The blockade of ESRs seems to be the major reason explaining the differences between both treatments. At least some of the effects of fulvestrant appear to result from compensatory mechanisms activated by the dramatic changes caused by ESR1 blockade.

Surgical treatment of male infertility in the era of intracytoplasmic sperm injection - new insights

Assisted reproductive technology is an evolving area, and several adjuvant procedures have been created to increase a couple's chance of conceiving. For male infertility, the current challenges are to properly accommodate old and new techniques that are both cost-effective and evidence-based. In this context, urologists are expected to diagnose, counsel, provide medical or surgical treatment whenever possible and/or correctly refer male patients for assisted conception. Urologists are sometimes part of a multiprofessional team in an assisted reproduction unit and are responsible for the above-cited tasks as well as the surgical retrieval of sperm from either the epididymides or testicles. We present a comprehensive review of the surgical treatment options for infertile males, including the perioperative planning and prognostic aspects, with an emphasis on the role of microsurgery in the optimization of treatment results. This review also discusses current techniques for sperm retrieval that are used in association with assisted reproductive technology and includes sperm retrieval success rates according to the technique and the type of azoospermia. New insights are provided with regard to each surgical treatment option in view of the availability of assisted conception to overcome male infertility.

Structure and ultrastructure of spermatozoa of Chrysomya megacephala (Diptera: Calliphoridae).

The spermatozoa of Chrysomya megacephala are similar to those described for other Brachycera. In this species, the spermatozoa are long and thin, measuring about 590microm in length, of which the head region measures approximately 60microm. The head includes a monolayered acrosome with electron-lucid material, and the shape of the nucleus, in cross-sections, varies from circular to oval with completely condensed chromatin. The centriole was observed in the zone of flagellar implantation, below the "peg" region. In the region of overlap, the followings structures are observed: nucleus, centriolar adjunct, mitochondrial derivatives and axoneme. The two mitochondrial derivatives are of different lengths but similar diameter. The axoneme is of a conventional insectan type with a 9+9+2 microtubular arrangement, with accessory tubules flanked by the electron-dense intertubular material. The male internal reproductive tract consists of testis, vas deferens, seminal vesicle, accessory glands and ejaculatory duct.

[Ejaculatory duct obstruction]. / Obstrucción de conductos eyaculadores.

BACKGROUND: Prostatic cysts are rare lesions with a reported incidence from 1 to 7.9%. They have been associated with primary infertility. The main characteristic is the benign course and positive prognosis after correct surgical management. CLINICAL CASES: We present three clinical cases, two with primary infertility and another with a history of primary infertility who presented with recurrent hemospermia and refractory medical treatment. All patients had hypospermia and alteration of the seminal parameters represented by moderate oligospermia (MOS), asteno- and teratozoospermia, in addition to hemospermia in two patients. Diagnosis was confirmed by transrectal ultrasound. Transurethral resection (TUR) of the cyst was performed in two cases and resection of the veru montanum in one, obtaining improvement in the seminal parameters after 1 month of follow-up and acceptable parameters for spontaneous conception at 6 months. CONCLUSIONS: Infertility associated with partially obstructed ejaculatory ducts may be suspected clinically by hypospermia. Transrectal ultrasound is essential to confirm the diagnosis. TUR of this lesion reestablishes the free passage of semen in almost all patients, with potential recovery of fertility 6 months after treatment.

Morphology of male reproductive system in three species of Trypoxylon (Trypargilum) Richards (Hymenoptera: Crabronidae).

Variations in the adult male reproductive system among different groups of Hymenoptera offer characteristics that help studies on behavior and phylogenetics. The objective of this study was to describe the adult male reproductive system of three Trypoxylon (Trypargilum) species. For that, tissues were disseced, fixed in 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.2 and postfixed in 1% osmium tetroxide. The material was dehydratated and embedded for light and electron transmission microscopes. The species have similar reproductive systems, which are formed by a pair of testes, each one with three fusiforme follicles, from which emerges an efferent duct that later joins forming a deferent duct. The deferent duct opens into an ejaculatory duct. The first half of the deferent duct is enlarged and differentiated in a region specialized in sperm storage, the seminal vesicle. The accessory gland flows in the post-vesicular region of the deferent duct. The testes and vesicles are both covered with a conjunctive capsule. Sexually mature individuals have all spermatogenesis stages in their follicles. Sperms are released from testes in bundles which are disorganized inside seminal vesicles.

Obstrucción de conductos eyaculadores / Ejaculatory duct obstruction

BACKGROUND: Prostatic cysts are rare lesions with a reported incidence from 1 to 7.9%. They have been associated with primary infertility. The main characteristic is the benign course and positive prognosis after correct surgical management. CLINICAL CASES: We present three clinical cases, two with primary infertility and another with a history of primary infertility who presented with recurrent hemospermia and refractory medical treatment. All patients had hypospermia and alteration of the seminal parameters represented by moderate oligospermia (MOS), asteno- and teratozoospermia, in addition to hemospermia in two patients. Diagnosis was confirmed by transrectal ultrasound. Transurethral resection (TUR) of the cyst was performed in two cases and resection of the veru montanum in one, obtaining improvement in the seminal parameters after 1 month of follow-up and acceptable parameters for spontaneous conception at 6 months. CONCLUSIONS: Infertility associated with partially obstructed ejaculatory ducts may be suspected clinically by hypospermia. Transrectal ultrasound is essential to confirm the diagnosis. TUR of this lesion reestablishes the free passage of semen in almost all patients, with potential recovery of fertility 6 months after treatment.

Morphology of male reproductive system in three species of Trypoxylon (Trypargilum) Richards (Hymenoptera: Crabronidae) / Morfologia do sistema reprodutor masculino em três espécies de Trypoxylon (Trypargilum) Richards (Hymenoptera: Crabronidae)

Variations in the adult male reproductive system among different groups of Hymenoptera offer characteristics that help studies on behavior and phylogenetics. The objective of this study was to describe the adult male reproductive system of three Trypoxylon (Trypargilum) species. For that, tissues were disseced, fixed in 2.5 percent glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.2 and postfixed in 1 percent osmium tetroxide. The material was dehydratated and embedded for light and electron transmission microscopes. The species have similar reproductive systems, which are formed by a pair of testes, each one with three fusiforme follicles, from which emerges an efferent duct that later joins forming a deferent duct. The deferent duct opens into an ejaculatory duct. The first half of the deferent duct is enlarged and differentiated in a region specialized in sperm storage, the seminal vesicle. The accessory gland flows in the post-vesicular region of the deferent duct. The testes and vesicles are both covered with a conjunctive capsule. Sexually mature individuals have all spermatogenesis stages in their follicles. Sperms are released from testes in bundles which are disorganized inside seminal vesicles.

Variações no sistema reprodutor entre os diferentes grupos de Hymenoptera oferecem caracteres que auxiliam nos estudos de comportamento e filogenia. O objetivo deste trabalho foi descrever o sistema reprodutor masculino de três espécies de Trypoxylon (Trypargilum). Para isso, os tecidos foram dissecados, fixados em glutaraldeído 2,5 por cento em tampão cacodilato de sódio 0,1 M, pH 7,2 e pós-fixados em tetróxido de ósmio a 1 por cento. O material foi desidratado e incluído para microscopias de luz e eletrônica de transmissão. As espécies possuem os sistemas reprodutores muito semelhantes, formados por um par de testículos, cada um com três folículos fusiformes, a partir dos quais emerge um ducto eferente que depois se juntam formando o ducto deferente. O ducto deferente termina no ducto ejaculatório. A primeira metade dos ductos deferentes é dilatada e diferenciada em uma região especializada no armazenamento de espermatozóides, a vesícula seminal. A glândula acessória desemboca na região pós-vesicular do ducto deferente. Testículos e vesículas seminais são envoltos por uma única cápsula conjuntiva. Indivíduos maduros sexualmente apresentam todos os estágios da espermatogênese em seus folículos. Os espermatozóides são liberados dos testículos em feixes, os quais estão desorganizados na vesícula seminal.

Effects of the antiestrogen fulvestrant (ICI 182,780) on gene expression of the rat efferent ductules.

The efferent ductules express the highest amount of estrogen receptors ESR1 (ERalpha) and ESR2 (ERbeta) within the male reproductive tract. Treatment of rats with the antiestrogen fulvestrant (ICI 182,780) causes inhibition of fluid reabsorption in the efferent ductules, leading to seminiferous tubule atrophy and infertility. To provide a more comprehensive knowledge about the molecular targets for estrogen in the rat efferent ductules, we investigated the effects of ICI 182,780 treatment on gene expression using a microarray approach. Treatment with ICI 182,780 increased or reduced at least 2-fold the expression of 263 and 98 genes, respectively. Not surprisingly, several genes that encode ion channels and macromolecule transporters were affected. Interestingly, treatment with ICI 182,780 markedly altered the expression of genes related to extracellular matrix organization. Matrix metalloproteinase 7 (Mmp7), osteopontin (Spp1), and neuronal pentraxin 1 (Nptx1) were among the most altered genes in this category. Upregulation of Mmp7 and Spp1 and downregulation of Nptx1 were validated by Northern blot. Increase in Mmp7 expression was further confirmed by immunohistochemistry and probably accounted for the decrease in collagen content observed in the efferent ductules of ICI 182,780-treated animals. Downregulation of Nptx1 probably contributed to the extracellular matrix changes and decreased amyloid deposition in the efferent ductules of ICI 182,780-treated animals. Identification of new molecular targets for estrogen action may help elucidate the regulatory role of this hormone in the male reproductive tract.

Endorectal magnetic resonance imaging in persistent hemospermia.

OBJECTIVE: To present the spectrum of abnormalities found at endorectal magnetic resonance imaging (E-MRI), in patients with persistent hemospermia. MATERIALS AND METHODS: A review of E-MRI findings observed in 86 patients with persistent hemospermia was performed and results compared with those reported in the literature. Follow-up was possible in 37 of 86 (43%) patients with hemospermia. RESULTS: E-MRI showed abnormal findings in 52 of 86 (60%) patients with hemospermia. These findings were: a) hemorrhagic seminal vesicle and ejaculatory duct, isolated (n = 11 or 21%) or associated with complicated midline prostatic cyst (n = 10 or 19.0%); b) hemorrhagic chronic seminal vesiculitis, isolated (n = 14 or 27%) or associated with calculi within dilated ejaculatory ducts (n = 2 or 4 %); c) hemorrhagic seminal vesicle associated with calculi within dilated ejaculatory duct (n = 4 or 7.7%) or within seminal vesicle (n = 4 or 7.7%); d) non-complicated midline prostatic cyst (n = 6 or 11.5%); and e) prostate cancer (n = 1 or 2%). Successful treatment was more frequent in patients with chronic inflammatory and/or obstructive abnormalities. CONCLUSION: E-MRI should be considered the modality of choice, for the evaluation of patients with persistent hemospermia.

Endorectal magnetic resonance imaging in persistent hemospermia

OBJECTIVE: To present the spectrum of abnormalities found at endorectal magnetic resonance imaging (E-MRI), in patients with persistent hemospermia. MATERIALS AND METHODS: A review of E-MRI findings observed in 86 patients with persistent hemospermia was performed and results compared with those reported in the literature. Follow-up was possible in 37 of 86 (43 percent) patients with hemospermia. RESULTS: E-MRI showed abnormal findings in 52 of 86 (60 percent) patients with hemospermia. These findings were: a) hemorrhagic seminal vesicle and ejaculatory duct, isolated (n = 11 or 21 percent) or associated with complicated midline prostatic cyst (n = 10 or 19.0 percent); b) hemorrhagic chronic seminal vesiculitis, isolated (n = 14 or 27 percent) or associated with calculi within dilated ejaculatory ducts (n = 2 or 4 percent); c) hemorrhagic seminal vesicle associated with calculi within dilated ejaculatory duct (n = 4 or 7.7 percent) or within seminal vesicle (n = 4 or 7.7 percent); d) non-complicated midline prostatic cyst (n = 6 or 11.5 percent); and e) prostate cancer (n = 1 or 2 percent). Successful treatment was more frequent in patients with chronic inflammatory and/or obstructive abnormalities. CONCLUSION: E-MRI should be considered the modality of choice, for the evaluation of patients with persistent hemospermia.

Expression and localization of muscarinic acetylcholine receptor subtypes in rat efferent ductules and epididymis.

The expression of muscarinic acetylcholine receptor (mAChR) subtypes (M(1)-M(5)) was studied in the rat efferent ductules and epididymis at the mRNA and protein levels. The relative abundance of each mAChR transcript subtype differed depending on the tissue and the epididymal region analyzed. The M(1) mAChR mRNA level was more abundant in the efferent ductules than in the caput and cauda of the epididymis. The M(2) mAChR mRNA level was similar between the efferent ductules and caput of the epididymis and higher in the cauda region. The M(3) mAChR mRNA level was low in the efferent ductules and caput of the epididymis, but high levels were detected in the cauda region. mRNAs for M(4) and M(5) mAChRs were not detected in these tissues. Our studies indicated a variable degree of immunostaining for each mAChR subtype in a cell-type and tissue-specific pattern. M(1) mAChR was detected over the efferent ductule epithelium. M(2) and M(3) mAChRs were observed in the apical region of the ciliated cells. Apical and narrow cells of the initial segment showed distinct staining by M(1) antibody, whereas a supranuclear reaction was noted in the principal cells of the caput of the epididymis. In addition, staining for M(1) and M(2) mAChRs was visible in the apical membrane of some epithelial cells of the cauda region. M(3) mAChR was detected in the peritubular smooth muscle of the efferent ductules and epididymis. Functional studies suggested the involvement of this subtype in epididymal tubule contraction. Thus, the cell-specific expression of the various mAChR subtypes in the efferent ductules and epididymis suggests that these receptors play a role in the modulation of luminal fluid composition and smooth muscle contraction.

Ultrasonido transrectal como guía para el diagnóstico y tratamiento de la obstrucción de los conductos eyaculadores / Transrectal us for diagnosis and treatment of ejaculatory duct obstruction

Introducción: La infertilidad masculina es causada en el 10 por ciento de los casos por obstrucción de las vías seminales (ViS). Cuando la obstrucción ocurre a nivel de los conductos eyaculadores (OCE) la resección transuretral (RTU) del verumontanum resulta una terapéutica efectiva. El objetivo de este trabajo es demostrar la utilidad del ultrasonido transrectal (USTr) intraoperatorio y la inyección transrectal contrastada de las ViS bajo radioscopia (RX) para determinar la causa y localización de la OCE y facilitar la RTU guiando al resectocopio en forma precisa hacia el sitio de obstrucción. Material y métodos: Entre junio 2001 y abril 2004 se evaluaron 7 pacientes con sospecha de OCE. Todos presentaban examen físico normal, espermograma con hipospermia (5= oligospermia y 2= azoospemia) y dilatación de las vesículas seminales (ViS). La técnica consistió en la punción de la porción dilatada de las ViS y la inyección de contraste iodado y azul de metileno bajo USTr, RX y uretroscopia. Una vez determinado el sitio de obstrucción se realizó la RTU, cuyo trayecto y magnitud fueron determinados por el USTr. El éxito terapéutico fue determinado en base a la mejoría del espermograma. Resultados. En todos (7/7) se arribó a un diagnóstico, encontrándose quistes de la línea media (n=4) estenosis del conducto eyaculador (ECE) bilateral (n=1), unilateral (n=1) e hipotonía de VS (n=1). Excepto este último (obstrucción funcional) todos fueron sometidos a RTU sin complicaciones. En todos los pacientes tratados (6/7) los espermogramas mejoran a los valores deseados. Conclusión: El USTr es un método útil para determinar la causa y el sitio de obstrucción de las ViS. Permite guiar la punción diagnóstica y facilita la labor de la RTU determinando en forma precisa y tiempo real el sitio y trayecto a resecar. De esta forma se realizan cirugías dirigidas con menor área de resección y menor número de potenciales complicaciones (AU)

Ultrasonido transrectal como guía para el diagnóstico y tratamiento de la obstrucción de los conductos eyaculadores / Transrectal us for diagnosis and treatment of ejaculatory duct obstruction

Introducción: La infertilidad masculina es causada en el 10 por ciento de los casos por obstrucción de las vías seminales (ViS). Cuando la obstrucción ocurre a nivel de los conductos eyaculadores (OCE) la resección transuretral (RTU) del verumontanum resulta una terapéutica efectiva. El objetivo de este trabajo es demostrar la utilidad del ultrasonido transrectal (USTr) intraoperatorio y la inyección transrectal contrastada de las ViS bajo radioscopia (RX) para determinar la causa y localización de la OCE y facilitar la RTU guiando al resectocopio en forma precisa hacia el sitio de obstrucción. Material y métodos: Entre junio 2001 y abril 2004 se evaluaron 7 pacientes con sospecha de OCE. Todos presentaban examen físico normal, espermograma con hipospermia (5= oligospermia y 2= azoospemia) y dilatación de las vesículas seminales (ViS). La técnica consistió en la punción de la porción dilatada de las ViS y la inyección de contraste iodado y azul de metileno bajo USTr, RX y uretroscopia. Una vez determinado el sitio de obstrucción se realizó la RTU, cuyo trayecto y magnitud fueron determinados por el USTr. El éxito terapéutico fue determinado en base a la mejoría del espermograma. Resultados. En todos (7/7) se arribó a un diagnóstico, encontrándose quistes de la línea media (n=4) estenosis del conducto eyaculador (ECE) bilateral (n=1), unilateral (n=1) e hipotonía de VS (n=1). Excepto este último (obstrucción funcional) todos fueron sometidos a RTU sin complicaciones. En todos los pacientes tratados (6/7) los espermogramas mejoran a los valores deseados. Conclusión: El USTr es un método útil para determinar la causa y el sitio de obstrucción de las ViS. Permite guiar la punción diagnóstica y facilita la labor de la RTU determinando en forma precisa y tiempo real el sitio y trayecto a resecar. De esta forma se realizan cirugías dirigidas con menor área de resección y menor número de potenciales complicaciones

Ultrastructure of the ducts of the reproductive tract of males of Melipona bicolor bicolor lepeletier (Hymenoptera, Apinae, Meliponini).

The present paper describes the ultrastructural features of seminal vesicle, post-vesicular vas deferens and ejaculatory duct of Melipona bicolor bicolor from newly emerged and mature males. Although the results do not show very consistent morphological signs of secretory activity by the epithelium of these organs, lipidic droplets and lamellar granules present in mature males' seminal vesicles and the vacuoles present in post-vesicular vas deferens are probably secretion. Besides, the spermatozoa in the lumen are immersed in a material of characteristic structure, which must be produced in superior regions of the reproductive system of immature males, not studied here. The presence of sperm cells, apparently in cytoplasm vesicles of seminal vesicle and post-vesicular vas deferens, suggests spermiophagy by their epithelium.

Histological and histochemical aspects of the penial glands of Girardia biapertura Sluys, 1997 (Platyhelminthes, Tricladida, Paludicola)

Girardia biapertura was described with sperm ducts penetrating the penis bulb, subsequently opening separately at the tip of the penis papilla and receiving the abundant secretion of penial glands. In the present work, the penial glands of this species have been histologically and histochemically analysed, and four types of secretory cells are distinguished. The openings of the penial glands into the intrabulbar and intrapapillar sperm ducts, designated here as intrapenial ducts, allow for the distinction between three histologically differentiated regions. The most proximal region possibly corresponds to the bulbar cavity of other freshwater triclads whereas the median and distal portions correspond to the ejaculatory duct. The proximal region of the intrapenial ducts receives mainly the openings of a secretory cell type (type I) that produces a proteinaceous secretion. A second type of secretory cell (type II) that secretes neutral mucopolyssacharides opens into the median region of the intrapenial ducts. The distal portion of the ducts receives two types of secretory cells (types III and IV) which secret glycoprotein and glycosaminoglycans, respectively. Types III and IV open also directly into the male atrium through the epithelium of the penis papilla. A comparison with the results presented here and those of other authors for species of Girardia is provided and the importance of the study of the penial glands for taxonomic characterisation of freshwater triclads is emphasised