Amebic liver abscess in rat: morphological evidence of innate immune modulation by the sympathetic nervous system / Absceso hepático amebiano en rata: evidencia morfológica de la modulación de la respuesta inmune innata por el sistema nervioso simpático

All organs of the immune system are innervated and almost all neurotransmitter receptors are present on immune cells. We studied the effects of sympathetic innervation in the development of amebic liver abscess (ALA) in rats. Our results showed that lack of sympathetic innervation promote a decrease in size of ALA. We found scarce amoebas, increased the number of neutrophils and a few collagen fibers surrounding the abscess, meanwhile in control group, we observed abscesses areas with typical necrosis including trophozoites and neutrophils. Macrophages were differentially distributed surrounding abscess area in control and vehicle groups, but equally located in and outside of the abscesses in sympathectomized rat. No significant differences were observed on NK cells in analysed groups. In cytokines quantification studies, we observed down-expression of IFN-g and TNF-a, moreover, we found overexpression of IL-10 in sympathectomized and ALA group. In conclusion, our results suggest that elimination of sympathetic nerve fibers in a model rat of amebic liver abscess induces reduction of the innate immune response and presence of amebas through the liver at seven days post-inoculation.

Todos los órganos del sistema inmune están inervados y casi todos los receptores para neurotransmisores están presentes en las células de la respuesta inmune. Nosotros estudiamos el efecto de la inervación simpática en el desarrollo del Absceso Hepático Amebiano (AHA) en ratas. Nuestros resultados muestran que la inervación simpática promueve una disminución en el tamaño del AHA. Nosotros encontramos áreas fibróticas bien definidas con algunas amibas, mayor número de neutrófilos y pocas fibras de colágena rodeando el área de daño, mientras que en el grupo control, nosotros observamos áreas con necrosis, trofozoítos y pocos neutrófilos en el área fibrótica. Los macrófagos se observaron distribuidos en el área fibrótica en los animales simpatectomizados, mientras que en los controles encontramos a los macrófagos distribuidos en la periferia del absceso. No se encontró diferencia significativa en la distribución y cantidad de células NK. En el estudio de citocinas nosotros observamos una disminución de IFN-g y TNF-a y un incremento de IL-10 en animales simpatectomizados. En conclusión, nuestros resultados sugieren que la eliminación de las fibras del sistema nervioso simpático en el modelo de AHA en rata, reduce la respuesta inmune innata y persisten amebas en el tejido dañados a los 7 días post-inoculación.

Rat dorsal prostate is necessary for vaginal adhesion of the seminal plug and sperm motility in the uterine horns

The rat prostate comprises dorsal, ventral and lateral lobes that are morphologically and biochemically distinct. Lesions to these structures are expected to affect the quality of the ejaculate and male fertility. In experiment 1, we analyzed ejaculate parameters of males that had chemical lesions of the dorsal or ventral lobes. At pre-lesion and at 5 and 20 days post-lesion males were mated, and after ejaculation, seminal fluid and seminal plug were obtained from the mated females. In experiment 2, the ventral lobes were ablated, and the ejaculate was analyzed. In experiment 3, the fertility of males with chemically-lesioned dorsal lobes or ablation of the ventral lobes was evaluated. Chemical lesion of the dorsal lobe prevented the adhesion of the seminal plug to vaginal walls. When these males were tested at 5-days postlesion, no sperm were found in uterus, and at 20-days post-lesion, the few sperm encountered showed slow progressive motility. None of the females that mated with dorsal lobe-lesioned males became pregnant. However, chemical lesion or ablation of the ventral lobes did not affect ejaculate or fertility. Our results indicate that the dorsal prostatic lobes are indispensable for reproductive success in males, and define parameters of ejaculate with which fertility can be estimated.