Thesis (Ph. D.)--University of Pretoria, 2002. / Includes bibliographical references.

The supraspinal control of descending inhibition of genital reflexes (such as ejaculation) is poorly understood but is important in our global comprehension of how neural signals are integrated to produce sexual behavior, and in our understanding of sexual dysfunction. Sexual dysfunctions, such as premature ejaculation/delayed ejaculation in men, and involuntary vaginal spasms, dyspareunia, and anorgasmia in women, are common. An underlying dysregulation of genital reflexes may produce these dysfunctions, especially in those individuals being treated for depression and anxiety with serotonergic drugs. The nucleus paragigantocellularis (nPGi) of the rat medulla has been described as a descending inhibitory system for genital reflexes in rats, and a homologue is known in humans. Through retrograde tracing of nPGi afferents with the tracer Fluorogold in rats, we found that a number of brain regions implicated in sexual behavior, such as the medial preoptic area, paraventricular nucleus of the hypothalamus, and periaqueductal gray (PAG) provide sexually dimorphic projections to the nPGi, and that many of these regions contain receptors for gonadal steroids and are active during sexual behavior. We also found that excitotoxic lesions of the nPGi with N-methyl-D-aspartate facilitate male sexual behavior by reducing the number of intromissions required for ejaculation, and decreasing ejaculation latency. In females, such lesions attenuated sexual behavior by reducing the amount of time the female spent mating and reducing the reinforcement value of vaginocervical stimulation. Lastly, we found that by removing the source of serotonin to the nPGi (from the ventrolateral PAG) with the serotonergic neurotoxin 5,7-DHT in male rats, we were able to mimic the effects of nPGi lesions and facilitated male sexual behavior indicating that serotonin neurotransmission at the level of the nPGi is critical for genital reflex control. Taken together our results indicate that the nPGi is an important site of integration of internal signals for the regulation of sexual behavior that is sexually dimorphic and under serotonergic control. Our understanding of normal and dysfunction genital reflex control, and possible treatment options in people, is complemented by these results.

Breast and penis augmentations are century old processes of body modification continuing in development and practice today. This Masters thesis is a content analysis of breast and penis augmentation print and internet advertisements to explore one facet of augmentation discourse presented in public space. Relevant theoretical literature includes fetish discourse and medical discourse as existing frameworks that conceptualize augmentation predominantly as a process of body fragmentation. After reviewing this literature, I expand to blend together perspectives from three body theorists, Maurice Merleau-Ponty, Michel Foucault and Judith Butler, as an alternate framework for embodiment. I then use content analysis to examine the data collected from 21 print sources and 27 internet sources. The data indicates fetish discourse, focusing on body fragmentation, is the dominant content in breast and penis augmentation advertisements; however, I argue in the conclusion that incorporating elements of embodiment into fetish discourse is a better perspective for future research.

Estudos em animais e humanos sugerem que níveis adequados de testosterona são necessários para preservar a integridade do tecido eretor peniano. Nenhum estudo prévio confirmou se as mudanças estruturais são reversíveis após longo período de deprivação hormonal. Foi proposto a avaliação, através de métodos quantitativos, as alterações estruturais no corpo cavernoso de ratos submetidos à castração cirúrgica; bem como o papel da reposição hormonal tardia na reversão das possíveis alterações estruturais. Foram usados 25 ratos Sprague-Dawley machos com aproximadamente 12 semanas de idade. Os animais foram divididos em 5 grupos compostos por 5 animais em cada grupo e tratados da seguinte forma: ORQ1 = Grupo submetido à orquiectomia e sacrificado após 1 mês. C1- Grupo controle morto após 1 mês. ORQ2 - Grupo orquiectomizado e morto após 2 meses. C2 - Grupo controle morto após 2 meses. T Grupo orquiectomizado que recebeu, após 1 mês, suplementação com undecanoato de testosterona na dose de 100mg/ Kg subcutâneo. Após 1 mês de reposição hormonal os animais foram mortos.No Resultado Houve uma redução significativa no valor absoluto do colágeno, músculo liso, espaço sinusoidal e área total do corpo cavernoso após 2 meses no grupo castrado, quando comparado ao controle. Em termos gerais a densidade não apresentou nenhuma diferença significativa entre os grupos. A reposição hormonal com testosterona foi capaz de reverter as alterações observadas, demonstrando um aumento dos elementos estudados. A metodologia utilizada permitiu mostrar que valores absolutos demonstram melhor o que de fato ocorre com os elementos observados, eliminando um víeis de análise, quando se consideram os valores relativos. Esses resultados sugerem que a reposição, mesmo quando realizada tardiamente, foi eficaz na reversibilidade das alterações geradas pela castração / Introduction. Studies in animals and humans have suggested that adequate levels of testosterone are necessary to preserve the integrity of penile erectile tissue. No previously reported studies have confirmed if these structural changes are reversible following long-term hormonal deprivation. To evaluate, through quantitative methods, the structural alterations in the corpora cavernosa of rats submitted to surgical castration as well as the role of late hormone replacement in reversing the possible structural alterations. We used 25 male Sprague-Dawley rats who were approximately 12 weeks of age. The animals were divided into 5 groups composed of 5 animals each and treated as follows. ORCHIEC-1 = group that underwent orchiectomy and were sacrificed after 1 month, C-1 = control group sacrificed after 1 month, ORCHIEC-2 = group that underwent orchiectomy and were sacrificed after 2 months, C-2 = control group sacrificed after 2 months, T = group that underwent orchiectomy, and after 1 month underwent testosterone replacement with a subcutaneous single dose of testosterone undecanoate at 100 mg/kg (T); after 1 month of hormonal replacement, the animals were sacrificed. Quantification of smooth muscle, collagen and elastic system fibers in controls and rats submitted to orchiectomy alone and with late hormonal replacement. There were a significant decrease in the absolute values of collagen, smooth muscle, sinusoidal space and total area of corpora cavernosa after 2 months in the castrated group when compared with controls. Overall, as regards density, no significant differences were observed among the groups. The hormonal replacement with testosterone was able to reverse the alterations observed, demonstrating an increase in the elements studied. The method used for this research allowed demonstrating that absolute values are reliable to quantify the structural alterations of corpora cavernosa structures. The results suggest that hormonal replacement, even when instituted at a late stage, is effective in reversing the corpora cavernosa alterations produced by castration

This master thesis consists of two main parts. The first of them represents a compilation of information and facts about baculum, specifically about its presence, function and evolution in mammals. Further I focused on biological characters of five genera of African muroid rodents (Acomys, Aethomys, Gerbilliscus, Saccostomus, Stenocephalemys), which were analyzed in detail in the second part of my thesis in respect of their penial and bacular morphology.

The thesis deals with sexually psychological factors of what makes males attracive. The theoretical part is based on the theory of evolutionary psychology. We are interested in heterosexual women's strategy when choosing a partner. Of the factors that may affect their partner choice, we have focused on one physical attribute, the penis. The attribution of the importance of penis size depends on the individual. However, we try to find a connection between penis perception as a significant factor of what makes male attractive and other aspects, not only sexuality. For the purpose of our research, we have developed a specific questionnaire which, through a series of questions, examines the attitude towards the importance of penis size. The second part of the questionnaire is more intimate, identifyinf the relationship status, sexual experience, phase of the cycle and the use of hormonal contraception. The questionnaire was simply called "Does Size Matter?". The administration was online and we addressed women through social networks. We received responses from 276 respondents. We found several differences in penis perception as an important factor. Women who have a friend with benefits (they meet a man just for sexual satisfaction) are more likely to consider penis size more important. Women who feel...

Embora a disfunção erétil seja um problema frequente em pacientes com diabete mellitus, poucos estudos avaliaram as alterações da estrutura peniana nesta condição. O objetivo foi avaliar a densidade volumétrica de colágeno, fibras do sistema elástico e células musculares lisas no corpo cavernoso (CC), corpo esponjoso (CE) e túnica albugínea (TA) no pênis de coelhos diabéticos. Foram utilizados vinte seis coelhos Nova Zelândia. A diabete foi induzida em 13 coelhos com 8 semanas de idade com injeção intravenosa de 100 mg/ kg de aloxano. 13 coelhos normais serviram como controle. Após 10 semanas os animais foram mortos com overdose de thiopenthal sódico endovenoso. Os pênis foram dissecados retirando-se um fragmento da porção média sendo fixado em formol 10% tamponado (pH 7.3). Todo material foi processado para inclusão em parafina seguindo a técnica histológica de rotina. A análise estereológica do colágeno, das fibras do sistema elástico e do músculo liso foi realizada em cortes de 5&#61549;m no sistema teste M42. Os dados foram expressos em densidade volumétrica (Vv %). A organização de colágeno foi avaliada pela coloração do Picrosirius red sob polarização. Vimos que na túnica albugínea de coelhos diabéticos, houve um aumento de 88% da espessura (p < 0.0003) com um acentuado turnover do colágeno. Além disso, o conteúdo de fibras elásticas foi 34% maior (p < 0.0001). No CC dos coelhos diabéticos o colágeno diminuiu 45% (p < 0.0001) com a presença de um colágeno mais organizado. As fibras do sistema elástico tiveram um decréscimo de 46% (p < 0.0001). A diabete induziu um aumento de 11% de colágeno no CE (p < 0.0235) com um acentuado turnover do colágeno. No CC de coelhos diabéticos houve um aumento de 40% de músculo liso (p < 0.0001), enquanto no CE uma diminuição de 38% (p <0.0001). Os tecidos do pênis foram afetados de formas diferentes pela diabete, possivelmente devido à heterogeneidade celular. Essas mudanças poderiam ter um impacto sobre o fluxo sanguíneo e resistência do tecido e, portanto, prejudicar a ereção. / Although erectile dysfunction is a frequent problem in patients with diabetes mellitus, few studies have evaluated penile structure alteration in this condition. To assess the volumetric density of collagen, elastic system fibers and smooth muscles cells in the corpora cavernosa (CC), corpus spongiosum (CE) and tunica albuginea (TA) in the penis of diabetic rabbits. Twenty-six New Zealand white rabbits were used. Diabetes was induced at 8 weeks of age in 13 rabbits by intravenous injection of 100 mg/kg of alloxan. The remaining 13 rabbits served as a control group. After 10 weeks, the rabbits were killed using sodium thiopenthal. Mid-shaft fragments of the penis were obtained and processed by routine histological techniques. Stereological analysis of collagen, elastic system fibers and smooth muscle was performed in 5-&#61549;m sections by using a M42 System Test grid. Data were expressed as volumetric density (Vv - %). Collagen organization was evaluated by Picrosirius red staining under polarization. In the TA of diabetic rabbits, thickness increased by 88% (p < 0.0003) with an enhanced collagen turnover. Moreover, the elastic fiber content was 34% higher (p < 0.0001). In the CC of diabetics, collagen was diminished by 45% (p < 0.0001) with a more organized collagen. The elastic fibers were decreased by 46% (p < 0.0001). Diabetes induced a 11% increase in CS collagen (p < 0.0235) with an enhanced collagen turnover. Smooth muscle in the CC of diabetic rabbits was increased by 40% (p < 0.0001), whereas in the CS it was decreased by a similar amount (p < 0.0001). Penile tissues were affected differently by diabetes, possibly due to cellular heterogeneity. These changes could have an impact on blood flow and tissue resistance, and therefore, might adversely affect erection.

Os aminoácidos L-arginina e L-glutamina foram analisados como protetores dos tecidos erétil do pênis contra os danos induzidos pela radiação. Grupos de ratos Wistar foram tratadas com: nenhuma intervenção, radiação pélvica e sacrifício 7 (RAD7) ou 15 (RAD15) dias; e radiação pélvica, a suplementação diária com L-arginina (A) ou L-glutamina (G), e sacrifício 7 (RAD7 + A, RAD7 + G) ou 15 (RAD15 + A, RAD15 + G) dias após irradiação. componentes estruturais do corpo cavernoso (CC), túnica albugínea do corpo esponjoso (TAC), e urotélio do pênis foram analisados através de métodos estereológicos e imuno-histoquímico. Os resultados mostraram que, no CC, o tecido conjuntivo foi maior nos RAD15 (p <0,04), mas essa mudança foi parcialmente revertido em RAD15 + G (p <0,05) e RAD15 + A (p <0,04). A matriz fibrosa das trabéculas CC estava manchada de colágeno tipo I. Nos RAD15, a intensidade da marcação foi aumentada, enquanto que em RAD15 + G + A e RAD15 a coloração era semelhante à dos controles. Nenhuma alteração de coloração foram observadas nos grupos que foram sacrificados sete dias após a radiação. Cavernosa teor de fibras elásticas na RAD15 foi aumentada (p <0,004), e este foi impedido de RAD15 + A (p <0,004), mas não em RAD15 + G. No TAC, os aminoácidos protegidos (p <0,02) contra o aumento da radiação induzida em fibras elásticas, mas apenas em RAD15. Densidade das células do urotélio e espessura urothellial, foram reduzidos em RAD15 (p <0,004), mas houve efeitos protetores dos dois aminoácidos. Em conclusão, a radiação induzida por alterações nas estruturas penianas tendem a ser mais pronunciado 15 dias após a sessão de radiação. Tanto A e G têm efeitos protetores contra estas alterações, sendo o primeiro um pouco mais eficaz. / We investigated whether arginine and glutamine protect penile tissues against radiation-induced damage. Groups of Wistar rats were treated with: no intervention; pelvic radiation, and sacrifice 7 (RAD7) or 15 (RAD15) days later; and pelvic radiation, daily supplementation with L-arginine (A) or L-glutamine (G), and sacrifice 7 (RAD7+A, RAD7+G) or 15 (RAD15+A, RAD15+G) days after radiation. Structural components in the corpus cavernosum (CC), tunica albuginea of the corpus spongiosum (TACS), and urothelium of the penis were analyzed using stereological and immunohistochemical methods. The results showed that in the CC, connective tissue was increased in RAD15 (p<0.04), but this change was partially prevented in RAD15+G (p<0.05) and RAD15+A (p<0.04). The fibrous matrix of the CC trabeculae was stained for collagen type I. In RAD15, the intensity of the labeling was increased, whereas in RAD15+G and RAD15+A the staining was similar to that of the controls. No staining changes were seen in the groups that were sacrificed seven days after radiation. Cavernosal elastic fiber content in RAD15 was increased (p<0.004), and this was prevented in RAD15+A (p<0.004), but not in RAD15+G. In TACS, the aminoacids protected (p<0.02) against radiation-induced increase in elastic fiber content, but only in RAD15. Cell density in the urothelium, and urothellial thickness, were reduced in RAD15 (p<0.004), but there were protective effects of both aminoacids. In conclusion, radiation-induced alterations in penile structures tend to be more pronounced 15 days after radiation session. Both A and G have protective effects against these changes, with the former being slightly more effective.

Estudos em animais e humanos sugerem que níveis adequados de testosterona são necessários para preservar a integridade do tecido eretor peniano. Nenhum estudo prévio confirmou se as mudanças estruturais são reversíveis após longo período de deprivação hormonal. Foi proposto a avaliação, através de métodos quantitativos, as alterações estruturais no corpo cavernoso de ratos submetidos à castração cirúrgica; bem como o papel da reposição hormonal tardia na reversão das possíveis alterações estruturais. Foram usados 25 ratos Sprague-Dawley machos com aproximadamente 12 semanas de idade. Os animais foram divididos em 5 grupos compostos por 5 animais em cada grupo e tratados da seguinte forma: ORQ1 = Grupo submetido à orquiectomia e sacrificado após 1 mês. C1- Grupo controle morto após 1 mês. ORQ2 - Grupo orquiectomizado e morto após 2 meses. C2 - Grupo controle morto após 2 meses. T Grupo orquiectomizado que recebeu, após 1 mês, suplementação com undecanoato de testosterona na dose de 100mg/ Kg subcutâneo. Após 1 mês de reposição hormonal os animais foram mortos.No Resultado Houve uma redução significativa no valor absoluto do colágeno, músculo liso, espaço sinusoidal e área total do corpo cavernoso após 2 meses no grupo castrado, quando comparado ao controle. Em termos gerais a densidade não apresentou nenhuma diferença significativa entre os grupos. A reposição hormonal com testosterona foi capaz de reverter as alterações observadas, demonstrando um aumento dos elementos estudados. A metodologia utilizada permitiu mostrar que valores absolutos demonstram melhor o que de fato ocorre com os elementos observados, eliminando um víeis de análise, quando se consideram os valores relativos. Esses resultados sugerem que a reposição, mesmo quando realizada tardiamente, foi eficaz na reversibilidade das alterações geradas pela castração / Introduction. Studies in animals and humans have suggested that adequate levels of testosterone are necessary to preserve the integrity of penile erectile tissue. No previously reported studies have confirmed if these structural changes are reversible following long-term hormonal deprivation. To evaluate, through quantitative methods, the structural alterations in the corpora cavernosa of rats submitted to surgical castration as well as the role of late hormone replacement in reversing the possible structural alterations. We used 25 male Sprague-Dawley rats who were approximately 12 weeks of age. The animals were divided into 5 groups composed of 5 animals each and treated as follows. ORCHIEC-1 = group that underwent orchiectomy and were sacrificed after 1 month, C-1 = control group sacrificed after 1 month, ORCHIEC-2 = group that underwent orchiectomy and were sacrificed after 2 months, C-2 = control group sacrificed after 2 months, T = group that underwent orchiectomy, and after 1 month underwent testosterone replacement with a subcutaneous single dose of testosterone undecanoate at 100 mg/kg (T); after 1 month of hormonal replacement, the animals were sacrificed. Quantification of smooth muscle, collagen and elastic system fibers in controls and rats submitted to orchiectomy alone and with late hormonal replacement. There were a significant decrease in the absolute values of collagen, smooth muscle, sinusoidal space and total area of corpora cavernosa after 2 months in the castrated group when compared with controls. Overall, as regards density, no significant differences were observed among the groups. The hormonal replacement with testosterone was able to reverse the alterations observed, demonstrating an increase in the elements studied. The method used for this research allowed demonstrating that absolute values are reliable to quantify the structural alterations of corpora cavernosa structures. The results suggest that hormonal replacement, even when instituted at a late stage, is effective in reversing the corpora cavernosa alterations produced by castration

Pacientes com diabetes mellitus (DM) têm elevadas taxas de disfunção erétil (ED). Diversos estudos examinaram esta associação. A associação entre o processo de hipertrofia vascular diabética e o grau de comprometimento dos seios cavernosos é pouco estudada. A proposta do presente estudo foi avaliar a estrutura vascular do tecido erétil de coelhos diabéticos e coelhos normais, através de histomorfometria computadorizada da artéria dorsal do pênis e dos seios vasculares cavernosos em ambos os grupos. Foram utilizados 20 coelhos adultos machos da raça Nova Zelândia, divididos em dois grupos com 10 animais cada, o grupo diabético (GD) e o grupo controle (GC). Os animais foram previamente anestesiados e os coelhos do grupo GD receberam aloxano na dose de 100mg/kg, via endovenosa para indução da diabetes. Após 10 semanas, os animais foram mortos e os pênis retirados. Fragmentos do pênis foram fixados em formalina tamponada durante 24-48 horas e processados para parafina. Para análise imunohistoquímica e identificação das fibras musculares lisas, foi utilizado o anticorpo anti alfa-actina. Foram feitas análises da espessura média das túnicas íntima e média da parede da artéria dorsal do pênis (ADP), densidade nuclear na túnica média e avaliação por microscopia de polarização do conteúdo colágeno na túnica adventícia. Na túnica íntima foram observadas vacuolizações no endotélio. Os valores encontrados para espessura de GC e GD foram respectivamente (em m): 35,0123,177 e 44,3308,434 (P=0,0350). Foi encontrada diferença na área média da parede da ADP (P=0,0179). Para densidade nuclear GC 0,0071540,001954 núcleos/&#956;m e GD 0,0048080,002069 núcleos/&#956;m (P=0,0855). Foram observadas mudanças na birrefringência das fibras colágenas na túnica adventícia, passando de alaranjado no grupo GC para esverdeado no grupo GD, indicando a mudança em sua espessura. A área ocupada pelos seios cavernosos apresentou diminuição significativa de 37 % no grupo diabético (P=0,0013). Este conjunto de alterações sugere que a hiperglicemia crônica provocada pelo diabetes levou a um processo de hipertrofia da musculatura lisa na parede vascular e nas trabéculas do corpo cavernoso, com diminuição da área dos seios, o que possivelmente altera as propriedades hemodinâmicas do órgão / Patients with diabetes mellitus (DM) have a high incidence of erectile dysfunction (ED). Several epidemiological studies have assessed the correlation between DM and ED. Evaluation of animal models demonstrated that neural and vascular changes seen with DM may be associated with ED. Vascular diseases such as microangiopathy, atherosclerosis, and hypertension are often observed in patients with DM. The aim of this study was to assess the morphological changes of penile vascular structures and the corpus cavernosum area in alloxan-induced diabetic rabbits. Twenty male rabbits (2 months old) were divided into two groups with 10 rabbits each, the control group (CG) and the diabetic group (DG). The animals from the DG received an intravenous injection of alloxan (100mg/kg) to induce DM. Ten weeks after the induction of DM, all animals were euthanized. Two fragments of the penile shaft were harvested and samples were processed and paraffin embedded. Sections (5&#61549;m) were cut and stained for histological and immunohistochemical markers. Nuclear protrusion toward the lumen, and cytoplasmic vacuolization were observed in the tunica intima of the dorsal artery of the penis in DG. The thicknesses of the tunica media increased significantly from 35.013,17 m in DG to 44.338,43 m in DG (p=0,0350). Was also observed a significant increase in the area of the tunica media (p=0,0179). There was no significant change in smooth muscle cell density in the tunica media of the dorsal artery of the penis (p=0,0855). The collagen fiber pattern of the tunica adventitia of the dorsal artery of the penis was different between the control and diabetic groups. There was a decrease of 37% in the area occupied by the cavernous sinuses in DG, and the difference between CG and DG was significant (p = 0.0013). Alloxan-induced DM in rabbits promotes important changes in penile vascular structures, thereby decreasing blood supply and affecting penile hemodynamics, leading to erectile dysfunction