Subacute high-refined carbohydrate diet leads to abnormal reproductive control of the hypothalamic-pituitary axis in female rats.

We previously reported that female rats placed on a diet containing refined carbohydrates (HCD) resulted in obesity and reproductive abnormalities, such as high serum LH concentration and abnormal ovarian function. However, the impacts at the hypothalamic-pituitary (HP) function, specifically regarding pathways linked to reproductive axis modulation are unknown. In this study, we assessed whether subacute feeding with HCD results in abnormal reproductive control in the HP axis. Female rats were fed with HCD for 15 days and reproductive HP axis morphophysiology was assessed. HCD reduced hypothalamic mRNA expression (Kiss1, Lepr, and Amhr2) and increased pituitary LHß+ cells. These changes likely contribute to the increase in serum LH concentration observed in HCD. Blunted estrogen negative feedback was observed in HCD, with increased kisspeptin protein expression in the arcuate nucleus of the hypothalamus (ARH), lower LHß+ cells and LH concentration in ovariectomized (OVX)+HCD rats. Thus, these data suggest that HCD feeding led to female abnormal reproductive control of HP axis.

Prolonged Activation of Brain CB2 Signaling Modulates Hypothalamic Microgliosis and Astrogliosis in High Fat Diet-Fed Mice.

Low-grade inflammation of the hypothalamus is associated with the disturbance of energy balance. The endocannabinoid system has been implicated in the development and maintenance of obesity as well as in the control of immune responses. The type 2 cannabinoid receptor (CB2) signaling has been associated with anti-inflammatory effects. Therefore, in high fat diet (HFD)-induced obese mice, we modulated CB2 signaling and investigated its effects on energy homeostasis and hypothalamic microgliosis/astrogliosis. We observed no effect on caloric intake and body weight gain in control diet-fed animals that received prolonged icv infusion of the CB2 receptor agonist HU308. Interestingly, we observed a decrease in glucose tolerance in HFD-fed animals treated with HU308. Prolonged icv infusion of HU308 increases astrogliosis in the ventromedial nucleus (VMH) of obese animals and reduced HFD-induced microgliosis in the hypothalamic arcuate (ARC) but not in the paraventricular (PVN) or VMH nuclei. These data indicate that central CB2 signaling modulates glucose homeostasis and glial reactivity in obesogenic conditions, irrespective of changes in body weight.

Spatial distribution and molecular epidemiology of hemotropic Mycoplasma spp. and Mycoplasma haemocanis infection in dogs from Rio de Janeiro, Brazil.

This cross-sectional study aims to investigate the epidemiology and spatial distribution of hemotropic Mycoplasma spp. and Mycoplasma haemocanis in dogs from Rio de Janeiro, Brazil. Blood samples were collected at random from 437 household dogs. An epidemiological questionnaire was completed concerning the host characteristics as well as the environments in which they lived. A positivity frequency of 17.84% (78/437) was found for Mycoplasma spp. and 2% (9/437) for M. haemocanis in Rio de Janeiro, Brazil, through molecular detection based on the 16S rRNA sequence. According to the present study, dogs that live in households with the presence of rodents (odds ratio [OR] = 9.93; p-value = 0.02; confidence interval [CI]: 1.34-73.66) and wild animals (OR = 1.91; p-value = 0.03; CI: 1.06-3.42) are more likely to be infected with Mycoplasma spp.. Also, dogs with tick infestation (OR = 6.47; p-value = 0.007; CI: 1.63-25.60) have more chances to become infected with M. haemocanis. The spatial analysis disclosed a positive correlation between the Mycoplasma presence and tick infestation (global Moran index = 0.82; pseudo-p-value =0.001). The epidemiological findings support the hypothesis of Rhipicephalus sanguineus s.l. as the vector of M. haemocanis in the studied region and provide insightful information to prevent the Mycoplasma spp. infection in dogs from Rio de Janeiro.