RESUMO
Ovarian functions decrease with perimenopause. The ovary has extrinsic innervation, but the neural influence on ovarian functions and dysfunction is not well-studied. The present study aimed to biochemically and morphometrically characterize the intrinsic neurons in ovaries from young adult, middle-aged, and senescent Long Evans CII-ZV rats (3, 12, and 15 months old, respectively). Ovaries were extracted from four rats of each age group (n = 12 total), cryopreserved, and processed for immunofluorescence studies with the primary NeuN/ß-tubulin and NeuN/tyrosine hydroxylase (TH) antibodies. The soma area and number of intrinsic neurons in the ovarian stroma, surrounding follicles, corpus luteum, or cyst were evaluated. The intrinsic neurons were grouped in cluster-like shapes in ovarian structures. In senescent rats, the intrinsic neurons were mainly localized in the ovarian stroma and around the cysts. The number of neurons was lower in senescent rats than in young adult rats (p < 0.05), but the soma size was larger than in young adult rats. Immunoreactivity to TH indicated the presence of noradrenergic neurons in the ovary with the same characteristics as NeuN/ß-tubulin, which indicates that they are part of the same neuronal group. Taken together, the findings indicate that the intrinsic neurons may be related to the loss of ovarian functions associated with aging.
Assuntos
Ovário , Tubulina (Proteína) , Envelhecimento , Animais , Feminino , Ratos , Ratos Long-Evans , Tirosina 3-Mono-OxigenaseRESUMO
The aims of the study were to determine the time-course of urinary incontinence recovery after vaginal distension (VD), elucidate the mechanisms of injury from VD leading to external urethral sphincter (EUS) dysfunction, and assess if transcutaneous electrical stimulation (TENS) of the dorsal nerve of the clitoris facilitates recovery of urinary continence after VD. Rats underwent 4-h VD, 4-h sham VD (SH-VD), VD plus 1-h DNC TENS, and VD plus 1-h sham TENS (SH-TENS). TENS or SH-TENS were applied immediately and at days 2 and 4 post-VD. Micturition behavior, urethral histochemistry and histology, EUS and nerve electrophysiology, and cystometrograms were evaluated. VD induced urine leakage and significantly disrupted EUS fibers and nerve-conduction (VD vs SH-VD group; p < 0.01). Urine leakage disappeared 13 days post-VD (p < 0.001). Structural and functional recovery of EUS neuromuscular circuitry started by day 6 post-VD, but did not fully recover by day 11 post-VD (p > 0.05). TENS significantly decreased the frequency of urine leakage post-VD (days 5-7; p < 0.01). We conclude that rat urinary continence after VD requires 2 weeks to recover, although urethra structure is not fully recovered. TENS facilitated urinary continence recovery after VD. Additional studies are necessary to assess if TENS could be used in postpartum women.
Assuntos
Parto , Estimulação Elétrica Nervosa Transcutânea/métodos , Uretra/patologia , Incontinência Urinária/terapia , Animais , Eletromiografia , Eletrofisiologia , Feminino , Compressão Nervosa , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Recuperação de Função Fisiológica , Fatores de Tempo , Incontinência Urinária por Estresse/fisiopatologia , Micção , Vagina/patologiaRESUMO
Opossums in the clade Didelphini are well known to be resistant to snake venom due to endogenous circulating inhibitors which target metalloproteinases and phospholipases. However, the mechanisms through which these opossums cope with a variety of other damaging venom proteins are unknown. A protein involved in blood clotting (von Willebrand Factor) has been found to have undergone rapid adaptive evolution in venom-resistant opossums. This protein is a known target for a subset of snake venom C-type lectins (CTLs), which bind it and then induce it to bind platelets, causing hemostatic disruption. Several amino acid changes in vWF unique to these opossums could explain their resistance; however, experimental evidence that these changes disrupt venom CTL binding was lacking. We used platelet aggregation assays to quantify resistance to a venom-induced platelet response in two species of venom-resistant opossums (Didelphis virginiana, Didelphis aurita), and one venom-sensitive opossum (Monodelphis domestica). We found that all three species have lost nearly all their aggregation response to the venom CTLs tested. Using washed platelet assays we showed that this loss of aggregation response is not due to inhibitors in the plasma, but rather to the failure of either vWF or platelets (or both) to respond to venom CTLs. These results demonstrate the potential adaptive function of a trait previously shown to be evolving under positive selection. Surprisingly, these findings also expand the list of potentially venom tolerant species to include Monodelphis domestica and suggest that an ecological relationship between opossums and vipers may be a broader driver of adaptive evolution across South American marsupials than previously thought.
Assuntos
Adaptação Fisiológica/fisiologia , Didelphis/fisiologia , Venenos de Serpentes/toxicidade , Fator de von Willebrand/metabolismo , Animais , Plaquetas/metabolismo , Lectinas Tipo C/metabolismo , Metaloproteases/metabolismo , Agregação Plaquetária , Venenos de Serpentes/química , Venenos de Serpentes/metabolismo , América do SulRESUMO
BACKGROUND: Electromyographic studies have shown that external anal sphincter activity is modified in response to distension in animals with spinal cord injury. Gonadotropin-releasing hormone and its agonist leuprolide acetate have neurotrophic properties in animals with spinal cord injury. AIM: This study was to determine the effects of leuprolide acetate treatment on electromyographic activity of the external anal sphincter and anorectal manometry in ovariectomized rats with spinal cord injury. METHODS: Adult ovariectomized rats were divided in three groups: (a) sham of spinal cord injury, (b) spinal cord injury treated with saline solution, and (c) spinal cord injury treated with leuprolide acetate. The spinal cord injury was induced by clamping at level T9. Leuprolide acetate dosage of 10 µg/kg was proctored intramuscular for 5 weeks, commencing the day after the lesion. Electromyography of the external anal sphincter, anorectal manometry, and volume of the cecum were evaluated in all groups. RESULTS: The electromyographic study of the external anal sphincter activity showed a significant improvement in injured rats treated with leuprolide acetate. Manometric analysis and cecum volume data obtained in animals with leuprolide acetate were very similar to those found in the sham group. CONCLUSIONS: These results demonstrate that leuprolide acetate treatment improves the neurogenic colon in ovariectomized rats with spinal cord injury.
Assuntos
Canal Anal/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/agonistas , Leuprolida/farmacologia , Intestino Neurogênico/fisiopatologia , Ovariectomia , Reto/efeitos dos fármacos , Traumatismos da Medula Espinal/fisiopatologia , Canal Anal/fisiopatologia , Animais , Ceco/efeitos dos fármacos , Ceco/fisiopatologia , Eletromiografia , Feminino , Manometria , Intestino Neurogênico/etiologia , Ratos , Ratos Wistar , Reto/fisiopatologia , Traumatismos da Medula Espinal/complicaçõesRESUMO
Opossums in the clade Didelphini are well known to be resistant to snake venom due to endogenous circulating inhibitors which target metalloproteinases and phospholipases. However, the mechanisms through which these opossums cope with a variety of other damaging venom proteins are unknown. A protein involved in blood clotting (von Willebrand Factor) has been found to have undergone rapid adaptive evolution in venom-resistant opossums. This protein is a known target for a subset of snake venom C-type lectins (CTLs), which bind it and then induce it to bind platelets, causing hemostatic disruption. Several amino acid changes in vWF unique to these opossums could explain their resistance; however, experimental evidence that these changes disrupt venom CTL binding was lacking. We used platelet aggregation assays to quantify resistance to a venom-induced platelet response in two species of venom-resistant opossums (Didelphis virginiana, Didelphis aurita), and one venom-sensitive opossum (Monodelphis domestica). We found that all three species have lost nearly all their aggregation response to the venom CTLs tested. Using washed platelet assays we showed that this loss of aggregation response is not due to inhibitors in the plasma, but rather to the failure of either vWF or platelets (or both) to respond to venom CTLs. These results demonstrate the potential adaptive function of a trait previously shown to be evolving under positive selection. Surprisingly, these findings also expand the list of potentially venom tolerant species to include Monodelphis domestica and suggest that an ecological relationship between opossums and vipers may be a broader driver of adaptive evolution across South American marsupials than previously thought
RESUMO
The aims of the present study were to describe, in male rats, the anatomical organization of the major and accessory pelvic ganglia (MPG, AG; respectively), the interrelationship of the pelvic plexus components, and the morphometry of the pelvic postganglionic neurons. Anatomical, histochemical and histological studies were performed in anesthetized adult Wistar male rats. We found that the pelvic plexus consists of intricate neural circuits composed of two MPG, and three pairs of AG (AGI, AGII, AGIII) anatomically interrelated through ipsilateral and contralateral commissural nerves. Around 30 nerves emerge from each MPG and 17 from AGI and AGII. The MPG efferent nerves spread out preganglionic information to several pelvic organs controlling urinary, bowel, reproductive and sexual functions, while AG innervation is more regional, and it is confined to reproductive organs located in the rostral region of the urogenital tract. Both MPG and AG contain nerve fascicles, blood vessels, small intensely fluorescent cells, satellite cells and oval neuronal somata with one to three nucleoli. The soma area of AG neurons is larger than those of MPG neurons (pâ¯<â¯0.005). The MPG contains about 75% of the total pelvic postganglionic neurons. Our findings corroborated previous reports about MPG inputs, and add new information regarding pelvic ganglia efferent branches, AG neurons (number and morphometry), and neural interrelationship between the pelvic plexus components. This information will be useful in designing future studies about the role of pelvic innervation in the physiology and pathophysiology of pelvic functions.
Assuntos
Fibras Autônomas Pré-Ganglionares , Gânglios Autônomos/anatomia & histologia , Plexo Hipogástrico/anatomia & histologia , Nervos Espinhais/anatomia & histologia , Animais , Masculino , Ratos , Ratos Wistar , Bexiga Urinária/inervaçãoRESUMO
The rat is the most common animal model for the preclinical validation of neuroprotective therapies in spinal cord injury (SCI). Lipid peroxidation (LP) is a hallmark of the damage triggered after SCI. Free radicals react with fatty acids causing cellular and membrane disruption. LP accounts for a considerable amount of neuronal cell death after SCI. To better understand the implications of inbred and outbred rat strain selection on preclinical SCI research, we evaluated LP after laminectomy sham surgery and a severe contusion of the T9 spinal cord in female Sprague-Dawley (SPD), Lewis (LEW), and Fischer 344 (F344) rats. Further analysis included locomotor recovery using the Basso, Beattie, and Bresnahan (BBB) scale and retrograde rubrospinal tract tracing. LEW had the highest levels of LP products 72 h after sham surgery and SCI, significantly different from both F344 and SPD. SPD rats had the fastest functional recovery and highest BBB scores; these were not significantly different to F344. However, LEW rats achieved the lowest BBB scores throughout the 2-month follow-up, yielding significant differences when compared to SPD and F344. To see if the improvement in locomotion was secondary to an increase in axon survival, we evaluated rubrospinal neurons (RSNs) via retrograde labeling of the rubrospinal tract and quantified cells at the red nuclei. The highest numbers of RSNs were observed in SPD rats then F344; the lowest counts were seen in LEW rats. The BBB scores significantly correlated with the amount of positively stained RSN in the red nuclei. It is critical to identify interstrain variations as a potential confound in preclinical research. Multi-strain validation of neuroprotective therapies may increase chances of successful translation.
RESUMO
In mammals, the pelvic striated muscles have been linked to the regulation of urinary functions and little is known about the involvement of this muscle in reproductive functions. The objective of this study was to use surgical and electrophysiological techniques to determine the anatomical features and innervation of iliococcygeus and pubococcygeus muscles in adult female rabbits and characterize the reflex electromyographic (EMG) activity in response to genital stimulation. Results show that the iliococcygeus and pubococcygeus are long bilateral muscles with fibers attached to the ilium bone. The muscle fibers are not attached to the pelvic viscera but they run adjacent to the vagina and rectum to be inserted into the sacral vertebrae. The iliococcygeus and pubococcygeus muscles are innervated by branches arising from S3 and S4. The reflex EMG activity was obtained during stimulation of the vaginal orifice skin and the perineal and pelvic vagina. Abdominal vaginal stimulation did not cause an EMG response. Cervical stimulation produced a temporary inhibition in the activity of the iliococcygeus and pubococcygeus. These findings extend the poor descriptions of innervation and anatomy of the striated pelvic musculature shown in the textbooks and atlas of rabbits. They also suggest that the iliococcygeus and pubococcygeous muscles can be activated by reflex action during reproductive processes such as mating and parturition.
En mamíferos, la musculatura estriada pélvica se ha relacionado con la regulación de funciones urinarias y poco se sabe de su participación en funciones reproductivas. Los objetivos del presente estudio fueron determinar las características anatómicas y la inervación de los músculos iliococcígeo y pubococcígeo de la coneja adulta, y caracterizar la actividad electromiográfica (EMG) refleja en respuesta a la estimulación genital. Para ello se utilizaron técnicas quirúrgicas y electrofisiológicas. Los resultados muestran que el iliococcígeo y pubococcígeo son músculos bilaterales que se originan en el hueso iliaco; están inervados por ramas que emergen de S3 y S4; sus fibras musculares no se adhieren a las vísceras pélvicas, sino que discurren lateral a la vagina y al recto y se insertan en las vértebras sacras. Durante la estimulación de la piel del orificio vaginal y la vagina pélvica y perineal se presentó actividad EMG refleja en ambos músculos. La estimulación de la vagina abdominal no indujo respuesta EMG. La estimulación cervical produjo inhibición temporal en la actividad del iliococcígeo y pubococcígeo. Estos resultados contribuyen a las escasas descripciones anatómicas de la musculatura pélvica de la coneja que se encuentran en libros de texto y atlas; también sugieren que los músculos pélvicos iliococcígeo y pubococcígeo podrían activarse reflejamente durante procesos reproductivos, como la cópula y el parto.
RESUMO
The damage in ischemic stroke is caused by two events: (i) the ischemic phenomenon by itself; (ii) the self-destructive mechanisms developed as a consequence of ischemia. The inflammatory response is one of these destructive phenomena that accompanies and exacerbates the developing injury. Since it has been suggested that immune cells participate in neuroprotective and restorative processes, modulation rather than elimination of this inflammatory response could be a strategy to improve the neurological outcome. The immune modulator copolymer-1 (Cop-1), a synthetic basic random copolymer of amino acids, is a potent inducer of Th2 regulatory cells which, aside from exerting modulatory actions, is capable of releasing neurotrophic factors. There is evidence that Cop-1-specific T cells exert neuroprotective and even restorative effects in diverse neurodegenerative diseases. In order to test the ability of Cop-1 to prevent ischemic injury in a model of transient middle cerebral artery (MCA) occlusion, two groups of rats were treated either with Cop-1 or with saline solution (SS). Seven days after occlusion, Cop-1 treated rats presented a significant improvement in neurological function compared to SS-treated animals (1.2+/-0.4 and 2.8+/-0.5 mean+/-S.D., respectively; p=0.008). Histological findings showed that the percentage of infarct volume was smaller in Cop-1 treated rats (4.8+/-1.5), in comparison with those receiving SS (32.2+/-8.6; p=0.004). Cop-1 constitutes a promising therapy for stroke; thereby, the enforcement of further experimental investigation is encouraged in order to be able to formulate the best strategy.
Assuntos
Encéfalo/efeitos dos fármacos , Infarto Cerebral/tratamento farmacológico , Encefalite/tratamento farmacológico , Infarto da Artéria Cerebral Média/tratamento farmacológico , Peptídeos/farmacologia , Recuperação de Função Fisiológica/efeitos dos fármacos , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Encéfalo/irrigação sanguínea , Encéfalo/fisiopatologia , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/imunologia , Isquemia Encefálica/fisiopatologia , Infarto Cerebral/imunologia , Infarto Cerebral/fisiopatologia , Citocinas/metabolismo , Encefalite/imunologia , Encefalite/fisiopatologia , Acetato de Glatiramer , Fatores Imunológicos/farmacologia , Fatores Imunológicos/uso terapêutico , Infarto da Artéria Cerebral Média/imunologia , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Fatores de Crescimento Neural/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Peptídeos/uso terapêutico , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica/imunologia , Células Th2/efeitos dos fármacos , Células Th2/metabolismo , Resultado do TratamentoRESUMO
Anatomical descriptions of the genitofemoral nerve (GFn) innervating the lower pelvic area are contradictory. Here we re-examine its origin and innervation by its various branches of principal target organs in the male rat. Using gross dissection, electrophysiological techniques and retrograde tracing of motoneurones with horseradish peroxidase, we confirm that the GFn originates from lumbar spinal nerves 1 and 2, and that at the level of the common iliac artery it divides into a lateral femoral and a medial genital branch. In contrast to previous studies, we report that the genital and not the femoral branch innervates the abdominal-inguinal skin, and not only the genital but also the femoral branch innervates the cremaster muscle (Cm) surrounding the testes. Motoneurones innervating the Cm proper are located in the ventral nucleus of L1 and L2, and those innervating the muscular transition region of the rostral Cm are located in the ventral nucleus in L1 and the ventrolateral nucleus in L2. The GFn may contribute to male reproductive performance by transmitting cutaneous information during copulation and, via contraction of the Cm to promote ejaculation, the protective displacement of the testes into the abdominal cavity during fighting and as a sperm-protecting thermoregulatory measure.
Assuntos
Nervo Femoral/anatomia & histologia , Genitália Masculina/inervação , Neurônios Motores/citologia , Vias Neurais , Abdome , Animais , Eletrofisiologia , Nervo Femoral/fisiologia , Histocitoquímica/métodos , Peroxidase do Rábano Silvestre , Masculino , Neurônios Motores/fisiologia , Músculo Esquelético/inervação , Ratos , Ratos Wistar , Pele/inervação , TestículoRESUMO
Little information is available on the participation of the perineal striated muscles in female reproductive processes. Here, we describe the gross anatomy and innervation of two striated perineal muscles in the female rabbit, the bulbospongiosus (BSM) and ischiocavernosus (ISM), and analyze their reflex electromyographic (EMG) activity in response to stimulation of the perigenital skin and vaginal tract. Twenty-four mature chinchilla-breed rabbit does were used: 12 to describe the anatomy and innervation of the muscles, 9 to determine reflex EMG activity of the muscles in response to stimulation of the perigenital skin and specific levels of the vaginal tract and 3 to analyze the effect of contraction of the muscles on intravaginal pressure. Both muscles were well developed, with their fibers originating at the ischiadic arch and inserting onto the ligamentum suspensorium clitoridis. Branches of the clitoral and perineal nerves innervated the BSM and ISM, respectively. Bilateral electrical stimulation of these nerves provoked retraction of the clitoral sheath and an increase in intravaginal pressure at the level of the perineal vagina. Whereas neither muscle responded to stimulation of the perigenital skin, both were reflexively activated during mechanical stimulation of the inner walls of the perineal vagina. Prolonged cervical stimulation inhibited this reflex. Thus, in reproductive processes such as copulation and/or parturition, the contraction of these muscles may be induced during stimulation of the perineal vagina.