Search results for "Estro."
showing 10 items of 770 documents
A mutation in the second intracellular loop of the pituitary adenylate cyclase activating polypeptide type I receptor confers constitutive receptor a…
2000
AbstractThe pituitary adenylate cyclase activating polypeptide (PACAP) type I receptor belongs to the glucagon/secretin/vasoactive intestinal polypeptide (VIP) receptor family. We mutated and deleted an amino acid residue (E261) which is located within the second intracellular loop of the rat PACAP type I receptor and which is highly conserved among the receptor family. The wild-type receptor and the mutant receptors were efficiently expressed at the surface of COS-7 cells at nearly the same level and revealed the same high affinity for the agonist PACAP-27. The cAMP contents of COS cells transfected with the E261A, E261Q, and the deletion mutant receptor were 4.6-, 5.7-, and 6.7-fold highe…
Interrelationship between reproductive hormones and acute phase proteins during estrous cycle and pregnancy in Spanish purebred broodmares
2021
Highlights • Steroid hormones and acute phase proteins in cyclic and pregnant mares were evaluated. • SAA and CRP did not discriminate cyclic and pregnant mares. • Pregnancy induced a limited acute phase response in Spanish purebred mares. • SAA, Hp and CRP were independent of E1 and P4 dynamics during pregnancy.
Daidzein has neuroprotective effects through ligand-binding-independent PPARγ activation.
2011
Phytoestrogens are a group of plant-derived compounds that include mainly isoflavones like daidzein. Phytoestrogens prevent neuronal damage and improve outcome in experimental stroke; however, the mechanisms of this neuroprotective action have not been fully elucidated. In this context, it has been postulated that phytoestrogens might activate the peroxisome proliferator-activated receptor-γ (PPARγ), which exerts neuroprotective effects in several settings. The aim of this study was to determine whether the phytoestrogen daidzein elicits beneficial actions in neuronal cells by mechanisms involving activation of PPARγ. Our results show that daidzein (0.05-5 μM) decreases cell death induced b…
Effects of LHRH, progesterone, estradiol-17 ? and dexamethasone in vitro on pineal synaptic ribbons and serotonin N-acetyltransferase activity in die…
1991
Pineal glands of regularly cycling Sprague Dawley rats (180-220 g) killed on the diestrous morning (between 0900-1000 h) were incubated in appropriate media for six hours with LHRH (8.5 microM), progesterone (3.2 microM), estradiol-17 beta (370 nM) or dexamethasone (250 nM). Pineals incubated in hormone-free medium and unincubated glands served as controls. Six rats were used in each group. After incubation the glands were divided into two parts. One part was used to estimate serotonin N-acetyltransferase (NAT) activity. The other part was processed for electron microscopy to quantify synaptic ribbons (SR). The SR numbers were computed to 20,000 microns 2 area of pineal tissue. The number a…
Targeting the vascular endothelial growth factor system to prevent ovarian hyperstimulation syndrome
2008
BACKGROUND: Ovarian hyperstimulation syndrome (OHSS) typically occurs when ovaries are primed with FSH/ LH and subsequently exposed to hCG. The ultimate pathophysiological step underlying this clinical picture is increased vascular permeability (VP). METHODS: A search of the literature was carried out using PubMed and the authors’ files. RESULTS: In rodents and humans, the expression of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR-2) mRNA increases during ovarian stimulation. With the administration of hCG, the expression of each rises to a maximum. Expression of VEGF/VEGFR-2 mRNAs correlates with enhanced VP, with both peaking 48 h following an injection of hCG. Imm…
The non-aromatizable androgen dihydrotestosterone (DHT) facilitates sexual behavior in ovariectomized female rats primed with estradiol
2020
Abstract It is still unclear whether Testosterone (T) increases sexual desire through a stimulation of the androgen receptor in relevant brain regions or through its conversion to estrogens. The aim of this study was to clarify the mechanisms of T facilitation of female sexual desire by assessing the effect of a non-aromatizable androgen (Dihydrotestosterone, DHT) in a validated animal model. Ovariectomized (OVX) Long-Evans rats were treated with oil (O) + O, 10 mcg Estradiol Benzoate (EB) + O, 10 mcg EB + 500 mcg Progesterone (P), O + 500 mcg DHT or 10 mcg EB + 500 mcg DHT (n = 12 per group). EB was administered 48 h, while P and DHT 4 h, prior to 4 sexual behavioral testing sessions in bi…
Effects of Environmental Lighting and Tryptophan Devoid Diet on the Rat Vaginal Cycle
1998
Cerebral serotonin level influences luteinizing hormone release and, consequently, ovulation. The present study evaluated the effects of precooked maize meal (polenta), a diet almost devoid of tryptophan the serotonin precursor on the alterations of the estrus cycle as measured by vaginal smears analysis in Wistar rats. Several conditions of environmental lighting were used in order to modify ovarian cycle: 1) natural alternating light/dark cycle; 2) continuous darkness; 3) continuous light by sodium steams: 4) continuous light by fluorescent neon tubes. Rats bred in continuous lighting showed estrus-proestrus rate significantly greater than rats bred in normal lighting or in continuous dar…
Ovarian size and blood flow in women with polycystic ovary syndrome (PCOS) and their correlations with some endocrine parameters
2005
Objective: To determine how common polycystic ovarian morphology may be in women given the clinical diagnosis of polycystic ovary syndrome (PCOS) based on chronic anovulation and hyperandrogenism and whether certain hormonal factors correlate with ovarian morphology and blood flow. Design: Prospective study. Setting: Two academic endocrinology centers in Italy. Patient(s): Three hundred twenty-six women with PCOS and 50 age-matched and weight-matched ovulatory women. Intervention(s): Ultrasound assessment of ovarian morphology in patients and controls and ovarian blood flow and fasting hormone levels in a subset of 50 patients and matched controls. Main Outcome Measure(s): Ovarian morpholog…
65 ASSOCIATION BETWEEN ALDOSTERONE AND CORTISOL LEVELS DURING THE OVULATORY PERIOD IN SPANISH PUREBRED MARES
2014
Preovulatory increased aldosterone (ALD) has been described as one of the physiological events that characterise the oestrous cycle in relation to the dynamics of the renin angiotensin aldosterone system. Within the mechanisms associated with this response are the stimulating effect of oestrogen on the synthesis of angiotensinogen, haemodynamic variations of renal blood flow, changes in sodium concentration, changes in the local sympathetic activity, and the effect of cortisol (CORT). In fact, CORT via adrenocorticotropic hormone contributes primarily to preovulatory ALD, and it is the primary regulator factor synthesis ALD (Chidambaram et al. 2002; Pechère-Bertschi et al. 2002; Szmuilowic…
Análisis del perfil de expresión de microRNA en células endoteliales humanas expuestas a estradiol. Papel del miR-30b-5p en la regulación de la expre…
2017
El endotelio es un tejido dinámico que juega un papel fundamental en el mantenimiento de la función vascular. Está localizado en la capa interna de los vasos sanguíneos, linfáticos y corazón, y resulta clave para las diversas funciones del sistema cardiovascular, tales como la hemostasia, la regulación del tono vascular, la respuesta inflamatoria, la regulación de la permeabilidad vascular y la angiogénesis. El endotelio actúa como una diana de los estrógenos y expresa ambos tipos de receptores de estrógenos (ER): los nucleares clásicos ERα and ERβ, que actúan como factores de transcripción, y el receptor acoplado a proteína G (GPER). Mientras que la unión de estrógenos a ERα y ERβ modula l…