Mario García-Lorenzana

Monosodium Glutamate Neonatal Intoxication Associated with Obesity in Adult Stage is Characterized by Chronic Inflammation and Increased mRNA Expression of Peroxisome Proliferator‐Activated Receptors in Mice

The monosodium glutamate (MSG) neonatal administration in mice provides a model of obesity with impaired glucose tolerance (IGT) and insulin resistance. However, the inflammatory profile of cytokines produced from fat tissue and its relationship to the metabolic dysfunction induced by MSG have not yet been revealed. The aim of this study was to establish the inflammatory profile attributed to MSG by measuring the expression of adipokines in visceral fat and serum of 19-week-old mice as well as the peroxisome proliferator-activated receptors alpha and gamma (PPARα and γ). Some metabolic and biochemical parameters were also quantified. The MSG increased mRNA expression of interleukin-6 (IL-6), tumour necrosis factor-alpha (TNFα), resistin and leptin, but adiponectin did not exhibit any changes. In addition, impaired glucose tolerance, increased levels of insulin, resistin and leptin were observed in serum. Both PPARα and PPARγ were activated in MSG-induced obese mice, which might explain its inflammatory profile. However, liver transaminases were severely depressed, indicating that MSG may also induce liver injury, contributing to inflammation. The MSG neonatal neuro-intoxication in mice may thus provide a model of obesity and inflammation characterized by the dual activation of PPARα and PPARγ, which might offer new insights into the mechanism of inflammatory diabetes in obesity leading to steatohepatitis, as well as a suitable model to study the role of new therapeutic agents to prevent or reduce insulin resistance, the inflammatory state and liver steatosis.

General tissue characteristics of the lower urethral and vaginal walls in the domestic rabbit.

In European rabbits, the distal urethra (DU) opens into the anterior pelvic vagina forming a single canal by which females copulate, give birth, and urinate. We investigated whether the histological characteristics of the DU and the pelvic and perineal vagina are different. The DU and vagina of rabbits (Oryctolagus cuniculus) were cut and stained with hematoxylin–eosin and Masson’s trichrome (n = 3). Data were compared by using Friedman’s ANOVA for repeated measures. The walls of the DU and vagina are composed of mucosa, submucosa, smooth muscle, and an external layer. Differences in tissue characteristics of the mucosa, orientation of the smooth muscle fibers, components of the external layer (connective tissue, blood vessels, and striated musculature), and thickness of the tissue layers were found among regions. The lack of histological homogeneity along the urethra and vagina possibly reflects differences in the functions of each segment.

Copulation without seminal expulsion: the consequence of sexual satiation and the Coolidge effect

The studies of sexual satiety in male rats under the Coolidge effect indicate that males reassume copulation until ejaculation. Recently, it was demonstrated that sexually satiated males preserve the motor patterns of intromission and ejaculation, also penile erection, but not seminal expulsion. The first aim was to investigate if penile erections displayed by sexually satiated males dislodge the seminal plugs from the vagina and its effect on sperm transcervical transport. The second aim was to determine the recovery time of seminal expulsion after sexual satiety and its optimal ability to induce pregnancy. Results show that during the Coolidge effect males were able to dislodge the seminal plugs deposited by others (experiment 1A) disturbing the sperm transport (experiment 1B) then interfering with pregnancy (experiment 1C). After satiation, the ejaculate parameters recover slowly: it starts after 10 days with the seminal plug formation, and continues with an increase in sperm count in the uterus 15 days post‐satiety (experiment 2). Sexually satiated males impregnated only 28% of the females during 15 days of cohabitation, whereas, satiated males that rested for 15 days impregnated 89% of the females (experiment 3). We concluded that males with successive ejaculations remain potential rivals, because they may disrupt the sperm transport of other males. The ejaculate features recovery after sexual satiety is gradual, begins with the secretions of the sex accessory glands and is followed by the sperm count. Full fertility recovery is reached after 15 days of sexual abstinence when males are able to impregnate most females.

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.

Amebic Liver Abscess in Rat: Morphological Evidence of Innate Immune Modulation by the Sympathetic Nervous System

Todos los organos del sistema inmune estan inervados y casi todos los receptores para neurotransmisores estan presentes en las celulas de la respuesta inmune. Nosotros estudiamos el efecto de la inervacion simpatica en el desarrollo del Absceso Hepatico Amebiano (AHA) en ratas. Nuestros resultados muestran que la inervacion simpatica promueve una disminucion en el tamano del AHA. Nosotros encontramos areas fibroticas bien definidas con algunas amibas, mayor numero de neutrofilos y pocas fibras de colagena rodeando el area de dano, mientras que en el grupo control, nosotros observamos areas con necrosis, trofozoitos y pocos neutrofilos en el area fibrotica. Los macrofagos se observaron distribuidos en el area fibrotica en los animales simpatectomizados, mientras que en los controles encontramos a los macrofagos distribuidos en la periferia del absceso. No se encontro diferencia significativa en la distribucion y cantidad de celulas NK. En el estudio de citocinas nosotros observamos una disminucion de IFN-g y TNF-a y un incremento de IL-10 en animales simpatectomizados. En conclusion, nuestros resultados sugieren que la eliminacion de las fibras del sistema nervioso simpatico en el modelo de AHA en rata, reduce la respuesta inmune innata y persisten amebas en el tejido danados a los 7 dias post-inoculacion.

Evaluation of HIF-1α and iNOS in ischemia/ reperfusion gastric model: Bioimpedance, histological and immunohistochemical analyses

Gastrointestinal ischemia/reperfusion (I/R) generates pathological alterations that could lead to death. Early ischemic damage markers could be used to guide therapy and improve outcomes. AIM To relate hypoxia-inducible factor 1α (HIF-1α) activation and inducible nitric oxide synthase (iNOS) expression to gastric impedance changes due to I/R damage. METHODS Experimental animals were randomly distributed into 3 groups: control, ischemia (30 min) and I/R (60 min). Gastric ischemia was generated by celiac artery clamping for 30 min, and then blood flow was restored for 60 min. Impedance spectra and biopsies of the glandular portion were obtained for histological and immunohistochemical analyses. Immunodetection of both HIF-1α and iNOS was performed. RESULTS Under ischemia and I/R conditions, there was an increase (p<0.05) in the impedance parameters. Histologically, under ischemic conditions, edema and necrosis were observed in epithelium and significant vascular congestion. In I/R condition, alterations of the glandular and luminal integrity were found, which generated areas of epithelial erosion. Immunohistochemical analysis of HIF-1α revealed an increase (p<0.01) in the number of immunoreactive cells in the ischemia (35.7±13.9) and I/R (119.9±18.8) conditions compared to the control (0.8±1.2). Immunodetection of iNOS showed an increase (p<0.01) in the number of cells expressing iNOS under the ischemia (5.4±2.9) and I/R conditions (27.4±11.3) was observed compared to the control (0.4±0.8). CONCLUSION Early changes in impedance in response to I/R is related to histopathological changes, the nuclear stabilization and translocation of HIF-1α as well as expression of iNOS.

Entamoeba histolytica L220 induces the in vitro activation of macrophages and neutrophils and is modulated by neurotransmitters

The neuroimmunoregulation of inflammation has been well characterized. Entamoeba histolytica provokes an inflammatory response in the host in which macrophages and neutrophils are the first line of defense. The aim of this study was to analyze the effect of the 220 kDa lectin of Entamoeba histolytica on stimulation of human macrophages and neutrophils, especially the secretion of cytokines and the relation of these to neurotransmitters. Human cells were interacted with L220, epinephrine, nicotine, esmolol and vecuronium bromide. The concentrations of IL-1β, IFN-γ, TNF-α and IL-10 were determined by ELISA at, 4 h of interaction. L220 has a cytokine stimulating function of macrophages and neutrophils for secretion of IL-1β, and IL-10 only by macrophages, which was modulated by the effect of vecuronium on cholinergic receptors in this immune cells.