FARNESOID X RECEPTOR AND REPRODUCTION

Farnesoid X alpha receptors (FXR? or NR1H4) are present in male and female reproductive tissues. The aim of the present review is to describe those actions of the most relevant ligands of FXR? on reproduction and the interaction of this receptor with other nuclear receptors, for understanding the possible role of FXR? in reproductive events. Thus, although the relevance of the FXR? on reproduction is widely unknown, its endogenous ligands like farnesol, chenodeoxycholic acid (CDCA), and cholate acid (CA) participate in proliferation, apoptosis, differentiation, and steroidogenesis in reproductive tissues. In these tissues FXR? modulates estrogen and androgen actions. Since FXR? is stretched related to other nuclear receptors, also present in reproductive tissues, such as the liver X receptors (LXR), peroxisome proliferation-activated receptor (PPAR), liver receptors homolog-1 (LRH-1), small heterodimer partner (SHP), and dosage-sensitive sex reversal (DAX1), the FXR? actions on reproductive tissues might be directly or indirectly mediated by its interaction with these nuclear receptors

Association between the serum concentration of triiodothyronine with components of metabolic syndrome, cardiovascular risk, and diet in euthyroid post-menopausal women without and with metabolic syndrome

PURPOSE: To determine the association between the serum concentration of triiodothyronine (T3) with components of metabolic syndrome (MetS), cardiovascular risk (CVR), and diet in euthyroid post-menopausal women without and with MetS. METHODS: A cross-sectional study was performed in 120 voluntary women of an indigenous population from Tlaxcala-México. Euthyroid status was assessed measuring the serum concentration of thyrotropin (TSH) and thyroid hormones, while that of estradiol was measured to confirm the postmenopausal condition. MetS was diagnosed using the American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement (AHA/NHLBI) criterion. Estimation of CVR was calculated based on the Framingham scale. Diet components were evaluated based on survey applications. Correlations, logistic regression analyses, ANOVA or Kruskall-Wallis, and chi-square tests were used to determine significant differences (P ≤ 0.05) between women without MetS and women with MetS having different serum concentrations of T3. RESULTS: Triiodothyronine was positively correlated with insulin but negatively correlated with glucose, high-density lipoprotein cholesterol (HDL-C), and CVR. Compared to women without MetS, women with MetS and low-normal T3 concentration showed a high risk for hyperglycemia and moderate/high risk for CVR. In contrast, a high-normal T3 concentration increased the risk to have a big waist circumference, a high concentration of HDL-C, and insulin resistance. Diet analysis showed a high grade of malnutrition in women from all groups. The intake of calories was positively affected by the T3 concentration, albeit it did not affect the extent of malnutrition. CONCLUSIONS: In contrast to concentrations of TSH, total thyroxin (T4), and free T4, the concentration of serum T3 was strongly correlated with cardio-metabolic variables in euthyroid postmenopausal women. In comparison to women without MetS, a high-normal serum concentration of T3 in women with MetS is positively associated with reduced glycaemia and CVR but negatively related to body mass index (BMI), insulin, insulin resistance, and HDL-C. Although the analyzed population had a nutritional deficiency, both calories and iron intake were positively affected by the T3 concentration. Our results suggest the necessity of health programs monitoring T3 in old people in order to treat hyperglycemia, cardio-metabolic components, and the ageing anorexia

High Estradiol Differentially Affects the Expression of the Glucose Transporter Type 4 in Pelvic Floor Muscles of Rats

Purpose To characterize the relationship between serum estradiol levels and the expression of glucose transporter type 4 (Glut4) in the pubococcygeus and iliococcygeus muscles in female rats. Methods The muscles were excised from virgin rats during the metestrus and proestrus stages of the estrous cycle, and from sham and ovariectomized rats implanted with empty or estradiol benzoate–filled capsules. The expression of estrogen receptors (ERs) was inspected in the muscles at metestrus and proestrus. Relative Glut4 expression, glycogen content, and serum glucose levels were measured. Appropriate statistical tests were done to identify significant differences (P≤0.05). Results The pubococcygeus and iliococcygeus muscles expressed ERα and ERβ. Glut4 expression and glycogen content in the pubococcygeus muscle were higher at proestrus than at metestrus. No significant changes were observed in the iliococcygeus muscle. In ovariectomized rats, the administration of estradiol benzoate increased Glut4 expression and glycogen content in the pubococcygeus muscle alone. Conclusions High serum estradiol levels increased Glut4 expression and glycogen content in the pubococcygeus muscle, but not in the iliococcygeus muscle

Review: Strategies for enteric methane mitigation in cattle fed tropical forages

Methane (CH4) is a greenhouse gas (GHG) produced and released by eructation to the atmosphere in large volumes by ruminants. Enteric CH4 contributes significantly to global GHG emissions arising from animal agriculture. It has been contended that tropical grasses produce higher emissions of enteric CH4 than temperate grasses, when they are fed to ruminants. A number of experiments have been performed in respiration chambers and head-boxes to assess the enteric CH4 mitigation potential of foliage and pods of tropical plants, as well as nitrates (NO3−) and vegetable oils in practical rations for cattle. On the basis of individual determinations of enteric CH4 carried out in respiration chambers, the average CH4 yield for cattle fed low-quality tropical grasses (>70% ration DM) was 17.0 g CH4/kg DM intake. Results showed that when foliage and ground pods of tropical trees and shrubs were incorporated in cattle rations, methane yield (g CH4/kg DM intake) was decreased by 10% to 25%, depending on plant species and level of intake of the ration. Incorporation of nitrates and vegetable oils in the ration decreased enteric CH4 yield by ∼6% to ∼20%, respectively. Condensed tannins, saponins and starch contained in foliages, pods and seeds of tropical trees and shrubs, as well as nitrates and vegetable oils, can be fed to cattle to mitigate enteric CH4 emissions under smallholder conditions. Strategies for enteric CH4 mitigation in cattle grazing low-quality tropical forages can effectively increase productivity while decreasing enteric CH4 emissions in absolute terms and per unit of product (e.g. meat, milk), thus reducing the contribution of ruminants to GHG emissions and therefore to climate change

Métodos y técnicas de monitoreo y predicción temprana en los escenarios de riesgos socionaturales

Esta obra concentra los métodos y las técnicas fundamentales para el seguimiento y monitoreo de las dinámicas de los escenarios de riesgos socionaturales (geológicos e hidrometeorológicos) y tiene como objetivo general orientar, apoyar y acompañar a los directivos y operativos de protección civil en aterrizar las acciones y políticas públicas enfocadas a la gestión del riesgo local de desastre

FARNESOID X RECEPTOR AND REPRODUCTION

Farnesoid X alpha receptors (FXRα or NR1H4) are present in male and female reproductive tissues. The aim of the present review is to describe those actions of the most relevant ligands of FXRα on reproduction and the interaction of this receptor with other nuclear receptors, for understanding the possible role of FXRα in reproductive events. Thus, although the relevance of the FXRα on reproduction is widely unknown, its endogenous ligands like farnesol, chenodeoxycholic acid (CDCA), and cholate acid (CA) participate in proliferation, apoptosis, differentiation, and steroidogenesis in reproductive tissues. In these tissues FXRα modulates estrogen and androgen actions. Since FXRα is stretched related to other nuclear receptors, also present in reproductive tissues, such as the liver X receptors (LXR), peroxisome proliferation-activated receptor (PPAR), liver receptors homolog-1 (LRH-1), small heterodimer partner (SHP), and dosage-sensitive sex reversal (DAX1), the FXRα actions on reproductive tissues might be directly or indirectly mediated by its interaction with these nuclear receptors

Hypothyroidism Affects Vascularization and Promotes Immune Cells Infiltration into Pancreatic Islets of Female Rabbits

Thyroidectomy induces pancreatic edema and immune cells infiltration similarly to that observed in pancreatitis. In spite of the controverted effects of hypothyroidism on serum glucose and insulin concentrations, the number and proliferation of Langerhans islet cells as well as the presence of extracellular matrix are affected depending on the islet size. In this study, we evaluated the effect of methimazole-induced hypothyroidism on the vascularization and immune cells infiltration into islets. A general observation of pancreas was also done. Twelve Chinchilla-breed female adult rabbits were divided into control n=6 and hypothyroid groups (n=6, methimazole, 0.02% in drinking water for 30 days). After the treatment, rabbits were sacrificed and their pancreas was excised, histologically processed, and stained with Periodic Acid-Schiff (PAS) or Masson’s Trichrome techniques. Islets were arbitrarily classified into large, medium, and small ones. The external and internal portions of each islet were also identified. Student-t-test and Mann-Whitney-U test or two-way ANOVAs were used to compare variables between groups. In comparison with control rabbits, hypothyroidism induced a strong infiltration of immune cells and a major presence of collagen and proteoglycans in the interlobular septa. Large islets showed a high vascularization and immune cells infiltration. The present results show that hypothyroidism induces pancreatitis and insulitis

Cytoplasmic regions adjacent to the M3 and M4 transmembrane segments influence expression and function of α7 nicotinic acetylcholine receptors. A study with single amino acid mutants

We studied the role of the cytoplasmic regions adjacent to the M3 and M4 transmembrane segments of α7 nicotinic receptors in the expression of functional channels. For this purpose, a total of 50 amino acids were mutated throughout the mentioned regions. Mutants close to M3, from Arg294 to Leu321, showed slight modifications in the levels of α-bungarotoxin binding sites and acetylcholine-evoked currents. Exceptions were mutants located at two clusters (His296 to Pro300 and Ile312 to Trp316), which exhibited low expression levels. In addition, some mutants showed altered functional responses. Many mutants close to M4 showed increased receptor expression, especially the ones located at the hydrophobic face of a putative amphipathic helix. This effect seems to be the consequence of a combination of increased receptor biosynthesis, higher transport efficiency and delayed degradation, such that we postulate that elements in the amphipathic domain strongly influence receptor stability. Finally, some mutants in this region showed altered functional responses: elimination of positively charged residues (Arg424 and Arg426) increased currents, whereas the opposite was observed upon suppression of negatively charged ones (Glu430 and Glu432). These results suggest that the cytoplasmic regions close to M3 and M4 play important structural and functional roles.This work was supported by grants from the Ministry of Education and Science of Spain and FEDER (BMC2002-00972, SAF2002-00209 and SAF2005-00534) and Generalitat Valenciana (GRUPOS03/038). FC was the recipient of a pre-doctoral fellowship (no. 153783) of the Consejo Nacional de Ciencia y Tecnologia from México.Peer reviewe