Inmunohistoquímica de la inervación del conducto deferente humano / Immunohistochemistry in the innervations of the human vas deferens

El conducto deferente humano presenta una pared muscular gruesa, donde el componente muscular liso ocupa la parte media y más prominente. Esta composición histológica le permite al órgano desarrollar las potentes contracciones durante el proceso de la eyaculación y emisión del semen. Objetivos: Analizar la presencia y distribución de la positividad inmunohistoquímica a Neurofilamentos (NF) en las paredes del conducto deferente humano. Pacientes, Materiales y Método: De tres pacientes sometidos a orquiectomía radical por diagnóstico de Seminoma, se obtuvieron los conductos deferentes fijados en formol tamponado (pH 7,2). Mediante procedimientos histológicos de rutina, se obtuvieron secciones de 5 um de espesor en portaobjetos silanizados. Se procedió al desarrollo del protocolo de inmunohistoquímica usando anticuerpos específicos contra Neurofilamentos (NF); las imágenes se obtuvieron con cámara fotográfica digital CCD Micrometrics, en microscopio óptico Olympus CX31. Resultados: En los subcompartimientos de las secciones transversales de la pared de los conductos deferentes humanos, se observa la reacción inmunohistoquímica positiva a NF. Sin embargo, los fascículos nerviosos se concentran en la adventicia, mientras que en la mucosa y pared muscular son en extremo escasos y finos. Conclusión: En el conducto deferente existe una inervación preferencial dispuesta en la adventicia del órgano, siendo posible que la potencia de la contracción de la pared en base a la actividad muscular, requiera factores adicionales de estimulación.

The human vas deferens has a thick muscular wall, where the smooth muscle component occupies the middle and most prominent. This composition allows the organ histologic develop powerful contractions during ejaculation process and the semen. Objectives. To analyze the presence and distribution of immunologically positlve for Neurofilament (NF) on the walls of human vas deferens. Patients, Materiall and Methods.' Three patients undergoing radical orchiectomy for seminoma diagnosis were obtained vas deferens fixed in buffered formain (pH 12). By routine histological procedures, sections were obtained 5 um thick on silylated slides. We proceeded to the development of immunohistochemical protocol using specific antibodies against Neurofilament (NF); the digitized images were obtained with CCO Micrometrics digital camera, in the light microscope Olympus CX31. Results: In the subcompartments of the cross sections of the wall of human vas deferens, there is a positive immunohistochemical reaction to NF However, nerve bundles are concentrated in the adventitia, whereas in the mucosa and muscle wall are extremely rare and fine. Conclusion: In the vas deferens there willing preferential innervation in the adventitia of the court, it being possible for the power of contraction of the wall of the body based on muscle activity, stimulation requires additional factors.

The serotonin paradox: drug-receptor interaction in rat vas deferens

The contractile effect of serotonin was studied in rat vas deferens, in comparison with that of noradrenaline and tyramine, after reserpine treatment, surgical denervation, and transplantation to the colon. In reserpinized animals the effect of 5HT resembled that of tyramine, since it was strikingly reduced, in spite of a small residual effect, showing that in normal preparations the effects of 5HT and tyramine are predominantly duc to the release of endogenous noradrenaline. However, in denervated or transplanted vas deferens, in which the effect of tyramine is also abolished, the effect of 5HT was potentiated. It is suggested that after chronic, long lasting depletion of endogenous noradrenaline, there are alternate mechanisms that are generated to improve the contractile effect of 5HT, but not of tyramine. The nature of these mechanisms is still unknown.

Does the release of tritiated noradrenaline accuratelly reflect the realease of endogenous noradrenaline from rat vas deferens nerve terminals?

To determine whether the release of tritiated noradrenaline (NA) from the sympathetic nerve terminals of the rat vas deferens is an accurate reflection of the release of endogenous NA, we compared the electrically-evoked release of tritiated and endogenous NA from the prostatic sections of the vasa deferentia of male rats. We found that while the release of tritiated NA was completely dependent on the presence of calcium, the release of endogenous NA was not. The overflow of both, tritiated and endogenous NA, was virtually unaffected by blockade of the neuronal uptake mechanism by desipramine. In contrast, blockade of the extraneuronal uptake greatly increased the overflow of endogenous NA, while having no effect on the overflow of tritiated NA. Tritiated NA release, on the other hand, was sensitive to prejunctional regulation, while the release of endogenous NA was not. Increases in stimulus train duration induced a significant increase in the release of endogenous NA, but not in that of tritiated NA. In contrast, the later responded to lower stimulus train frequencies and reached a plateau at lower frequency values as compared to the endogenous NA release. Our results indicate the existence of marked differences between the release of tritiated and endogenous NA. We conclude that: 1) the assumption that tritiated NA release provides a good marker for endogenous NA release in the rat was deferens seems unwarranted; 2) the use of endogenous NA to study the release process in the vas deferens requires a re-examination of the experimental conditions used, in order to minimize possible artifacts that may obscure the study of neuronal release; 3) the choice between measuring the release of tritiated or endogenous NA must be evaluated for each tissue in particular, taking into account its cytoarchitecture, as well as the experimental conditions used

Pre and post-synaptic muscarinic receptors of the rat vas deferens: an update

Los receptores muscarínicos pre- y post sinápticos del vas deferens de la rata no son M1 ya que el antagonista muscarínico M1-selectivo pirenzepina (PZ) posee baja afinidad por ambos. Basándonos en este hecho las dos acciones de ACh, pre-0y post-sinápticas, en esta preparación parecen ser mediadas por receptores muscarínicos parecidos al subtipo M2. La siguiente serie de observaciones experimentales revelan que ambas respuestas son mediadas por receptores muscarínicos farmacológicamente distintos. El rango de orden de potencia desplegado por 3 antagonistas muscarínicos (Atropina, N-metil-escopolamina [NMS] y PZ) en cada uno de estos lugares son diferentes. Atropina y PZ son bloqueadores selectivos del receptor muscarínico presente en músculo liso. NMS es un antagonista selectivo del receptor pre-sináptico muscarínico que facilita la liberación de norepinefrina. Por último, PZ y NMS despliegan un antagonismo diferencial, siendo competitivos y no-competitivos pre- y post-sinápticamente, respectivamente. Los resultados sugieren que el receptor muscarínico post-sináptico presente en el músculo liso pertenece a los subtipos M2B (oM3). El receptor pre-sináptico pertenece a los subtipos M2A (o M2) o a una subclase de los receptores muscarínicos M2B (o M3)