32 research outputs found

    Frequency components of systolic blood pressure variability reflect vasomotor and cardiac sympathetic functions in conscious rats

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    In this study, after confirming the suppression of autonomic nervous function by isoflurane anesthesia using autonomic antagonists, we pharmacologically investigated the involvement of vasomotor and cardiac sympathetic functions in systolic blood pressure variability (SBPV) frequency components in conscious rats at rest and during exposure to low-ambient temperature (LT-exposure, 9°C for 90 min). Under unanesthesia, phentolamine administration (α-adrenoceptor antagonist, 10 mg/kg) decreased the mid-frequency component (MF 0.33–0.73 Hz) and inversely increased the high-frequency component (HF 1.3–2.5 Hz). The increased HF was suppressed by subsequent treatment with atenolol (β-adrenoceptor antagonist, 10 mg/kg), but not with atropine (muscarinic receptor antagonist, 10 mg/kg). Moreover, phentolamine administration after atenolol decreased MF, but did not increase HF. LT-exposure increased MF and HF; however, phentolamine pretreatment suppressed the increased MF during LT-exposure, and atenolol pretreatment dose-dependently decreased the increased HF. These results suggest that MF and HF of SBPV may reflect α-adrenoceptor-mediated vasomotor function and β-adrenoceptor-mediated cardiac sympathetic function, respectively, in the conscious state

    Diagnostic management of cheilitis. An approach based on a recent proposal for cheilitis classification

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    Currently, there are no clear recommendations for diagnostic management of lip inflammation and cheilitis, which is evident in the varied nomenclature and subtypes found in medical literature on cheilitis. This can confound diagnostic management. We therefore recently put forth a proposal for cheilitis classification, defining three groups of cheilitis based on duration and etiology: mainly reversible cheilitis, mainly irreversible cheilitis, and cheilitis connected to other diseases. The most common forms of cheilitis are the reversible types, usually of short duration and commonly easily resolved or treated. In contrast, irreversible types of cheilitis are rare, are harder to treat, and are confirmed only after a biopsy of an inflamed lesion. To correctly diagnose and manage the different types, practitioners must consider several factors, including visible manifestations of the disease, related diseases and symptoms, personal habits, weather conditions, allergies, nutritional deficiencies, and results from tissue swabs and biopsies. In addition, multispecialty collaboration and communication involving dermatology, oral pathology, clinical immunology, otorhinolaryngology, rheumatology, and other fields can be crucial for patient outcome. We believe our classification system would be of great benefit to researchers, patients, and doctors by simplifying both nomenclature and disease recognition, thus ensuring timely and adequate treatment

    Blockade of central vasopressin receptors reduces the cardiovascular response to acute stress in freely moving rats

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    To investigate the contribution of central vasopressin receptors to blood pressure (BP) and heart rate (HR) response to stress we injected non-peptide selective V-1a (SR49059), V-1b (SSR 149415), V-2 (SR 121463) receptor antagonists, diazepam or vehicle in the lateral cerebral ventricle of conscious freely moving rats stressed by blowing air on their heads for 2 min. Cardiovascular effects of stress were evaluated by analyzing maximum increase of BP and HR (MAX), latency of maximum response (LAT), integral under BP and HR curve (integral), duration of their recovery and spectral parameters of BP and HR indicative of increased sympathetic outflow (LFBP and LF/HFHR). Moreover, the increase of serum corticosterone was measured. Exposure to air-jet stress induced simultaneous increase in BP and HR followed by gradual decline during recovery while LFBP oscillation remained increased as well as serum corticosterone level. Rats pre-treated with vasopressin receptor antagonists were not sedated while diazepam induced sedation that persisted during exposure to stress. V-1a, V-1b and V-2, receptor antagonists applied separately did not modify basal values of cardiovascular parameters but prevented the increase in integral(BP). In addition, V-1b and V-2 receptor antagonists reduced BPMAX whereas V-1a, V-1b antagonist and diazepam reduced HRMAX induced by exposure to air-jet stress. All drugs shortened the recovery period, prevented the increase of LFBP without affecting the increase in serum corticosterone levels. Results indicate that vasopressin receptors located within the central nervous system mediate, in part, the cardiovascular response to air-jet stress without affecting either the neuroendocrine component or inducing sedation. They support the view that the V-1b receptor antagonist may be of potential therapeutic value in reducing arterial pressure induced by stress-related disorders

    The hypothalamic-neurohypophyseal system:from genome to physiology

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    The elucidation of the genomes of a large number of mammalian species has produced a huge amount of data on which to base physiological studies. These endeavours have also produced surprises, not least of which has been the revelation that the number of protein coding genes needed to make a mammal is only 22,333 (give or take). However, this small number belies an unanticipated complexity that has only recently been revealed thanks to genomic studies. This complexity is evident at a number of levels: (1) cis-regulatory sequences; (2) non-coding and anti-sense mRNAs, most of which have no known function; (3) alternative splicing that results in the generation of multiple, subtly different mature mRNAs from the precursor transcript encoded by a single gene; (4) post-translational processing and modification. In this review, we examine the steps being taken to decipher genome complexity in the context of gene expression, regulation and function in the hypothalamo-neurohypophyseal system (HNS). Five unique stories explain: (1) the use of transcriptomics to identify genes involved in the response to physiological (dehydration) and pathological (hypertension) cues; 2) the use of mass spectrometry for single-cell level identification of biological active peptides in the HNS, and to measure in vitro release; (3) the use of transgenic lines that express fusion transgenes that enable (by cross-breeding) the generation of double transgenic lines that can be used to study vasopressin (AVP) and oxytocin (OXT) neurones in the HNS, their neuroanatomy, electrophysiology, and activation upon exposure to any given stimulus; (4) the use of viral vectors to demonstrate that somato-dendritically released AVP plays an important role in cardiovascular homeostasis by binding to V1a receptors on local somata and dendrites; and (5) the use of virally-mediated optogenetics to dissect the role of OXT and AVP in the modulation of a wide variety of behaviours
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