Glutathione Peroxidase to Genes Expression in Experimental Brain Tumors Reveals Gender-Dependent Patterns.

Extensive research efforts in the field of brain tumor studies have led to the reclassification of tumors by the World Health Organization (WHO) and the identification of various molecular subtypes, aimed at enhancing diagnosis and treatment strategies. However, the quest for biomarkers that can provide a deeper understanding of tumor development mechanisms, particularly in the case of gliomas, remains imperative due to their persistently incurable nature. Oxidative stress has been widely recognized as a key mechanism contributing to the formation and progression of malignant tumors, with imbalances in antioxidant defense systems being one of the underlying causes for the excess production of reactive oxygen species (ROS) implicated in tumor initiation.

Physiopathology of Osteoporosis: Nursing Involvement and Management.

Osteoporosis is a major public health problem today. We are facing an aging society where the average life expectancy continues to increase. Osteoporosis affects more than 30% of postmenopausal women due to hormonal changes that occur during this time.

Circulating levels of β-endorphin and cortisol in breast cancer.

Neurobehavioral stress can promote the growth and progression of different types of cancer because psychological factors can alter immune and endocrine function. β-endorphin is one of the hormones involved in the bidirectional connection between the immune and neuroendocrine systems that explains the effects of stress on the immune capacity against cancer. Breast cancer (BC) is the most common type of cancer in women and one of the best known to influence the different stressors involved in coping with the disease.

Insulin-Regulated Aminopeptidase in Women with Breast Cancer: A Role beyond the Regulation of Oxytocin and Vasopressin.

Insulin-regulated aminopeptidase (IRAP) is the only enzyme known to cleave oxytocin and vasopressin; however, it is also the high-affinity binding site for angiotensin IV (AngIV) receptor type 4 (AT4) ligands and it is related to insulin-dependent glucose transporters through the translocation of the glucose transporter type 4 (GLUT4). Previous studies have demonstrated an association between IRAP activity and the number and size of mammary tumors in an animal model of breast cancer (BC). Also, a highly significant increase in IRAP activity has been found in BC tissue from women patients.

Neoadjuvant chemotherapy modifies serum pyrrolidone carboxypeptidase specific activity in women with breast cancer and influences circulating levels of GnRH and gonadotropins.

Purpose: Functional studies have demonstrated that gonadotropin-releasing hormone (GnRH) regulates cell proliferation, apoptosis, and tissue remodeling. GnRH is metabolized by the proteolytic regulatory enzyme pyrrolidone carboxypeptidase (Pcp) (E.C.

Gender Differences in the Antioxidant Response to Oxidative Stress in Experimental Brain Tumors.

Background: Brain tumorigenesis is related to oxidative stress and a decreased response of antioxidant defense systems. As it is well known that gender differences exist in the incidence and survival rates of brain tumors, it is important to recognize and understand the ways in which their biology can differ.

Objective: To analyze gender differences in redox status in animals with chemically-induced brain tumors.

Normolipidic dietary fat modifies circulating Renin-Angiotensin system-regulating aminopeptidase activities in rat with breast cancer.

Hypothesis: Renin-angiotensin system (RAS) has been considered not only as a regulator of systemic volume and electrolyte balance but also has been recently involved in various pathological processes such as cancer. In the etiology of breast cancer, dietary factors have been analyzed and especially the influence of dietary fat has been studied, but the underlying mechanisms remain unclear. In this study, we analyzed RAS-regulating enzymes in serum of rats with N-methyl nitrosourea (NMU)-induced breast cancer fed with different diets.

Silver(I)/6-hydroxyiminolumazine compounds differently modify renin-angiotensin system-regulating aminopeptidases A and N in human neuroblastoma and glioma cells.

We have described that local tissue renin-angiotensin-system (RAS) is involved in tumor growth in a rat model of experimental glioma in vivo, through the modification of their corresponding local proteolytic regulatory enzymes. Thus, we have found a time-dependent significant decrease in aminopeptidase N (APN) and a significant increase in aminopeptidase A (APA) activities concomitantly with tumor growth in tumor tissue whereas no changes were found in circulating aminopeptidase activities; we suggested that angiotensin peptides may play an essential step in both tumor infiltration and associated angiogenesis. Here we analyze in vitro the antiproliferative efficacy, apoptotic properties and effects of three new disilver complexes containing E-6-(hydroxyimino)ethyl-1,3,7-trimethyllumazine (lumazine=pteridine-2,4(1H,3H)-dione) on RAS-regulating APA and APN specific activities in human neuroblastoma and glioma cell lines NB69 and U373-MG.

Plasma renin-angiotensin system-regulating aminopeptidase activities are modified in early stage Alzheimer's disease and show gender differences but are not related to apolipoprotein E genotype.

Alterations in blood pressure and components of the renin-angiotensin system (RAS) contribute to the development and progression of Alzheimer's disease (AD), resulting in changes that can lead or contribute to cognitive decline. Aspartyl aminopeptidase (ASAP), aminopeptidase A (APA), aminopeptidase N (APN) and aminopeptidase B (APB) catabolise circulating angiotensins, whereas insulin-regulated aminopeptidase (IRAP) has been described as the AT4 receptor. We have found in AD patients a significant decrease of APA activity in men but not in women, and of APN, APB and IRAP in both genders, when compared with control subjects.

Serum specific vasopressin-degrading activity is related to blood total cholesterol levels in men but not in women.

The role of vasopressin (AVP) in the pathophysiology of cardiovascular disease is controversial, but this peptide hormone is elevated in heart failure and some forms of hypertension. Also, AVP has vasoconstrictor, mitogenic, hyperplasic and renal fluid retaining properties which, by analogy with angiotensin II, may have deleterious effects when present in chronic excess. Furthermore, cholesterol blood levels are also associated with hypertension, although the underlying mechanism is not known.

Alpha-1-adrenergic receptor blockade modifies insulin-regulated aminopeptidase (IRAP) activity in rat prostate and modulates oxytocin functions.

Background: Oxytocin (OT) is one of the important paracrine factors that prostate synthesizes. OT maintains its resting tone and stimulates its contractile activity. However, the involvement of OT in modulating cell proliferation of the prostate is being investigated.

Diet-induced hypercholesterolemia impaired testicular steroidogenesis in mice through the renin-angiotensin system.

Hypercholesterolemia and low testosterone concentrations in men are associated with a high risk factor for atherosclerosis. It is known that cholesterol serves as the major precursor for the synthesis of the sex hormones. The bioactive peptides of the renin-angiotensin-system localized in the gonads play a key role in the relation between cholesterol and testosterone by modulating steroidogenesis and inhibiting testosterone production.

Hypothalamus-pituitary-thyroid axis disruption in rats with breast cancer is related to an altered endogenous oxytocin/insulin-regulated aminopeptidase (IRAP) system.

Associations of breast cancer with diseases of the thyroid have been repeatedly reported, but the mechanism underlying this association remains to be elucidated. It has been reported that oxytocin (OXT) attenuates the thyroid-stimulating hormone (TSH) release in response to thyrotrophin-releasing hormone (TRH) and decreased plasma levels of TSH as well as the thyroid hormones by an effect mediated by the central nervous system. Oxytocinase (IRAP) is the regulatory proteolytic enzyme reported to hydrolyze OXT.