Functional evidence that S-nitroso-L-cysteine may be a candidate carotid body neurotransmitter.

The primary objective of the present study is to provide further evidence that the endogenous S-nitrosothiol, S-nitroso-L-cysteine (L-CSNO), plays an essential role in signaling the hypoxic ventilatory response (HVR) in rodents. Key findings were that (1) injection of L-CSNO (50 nmol/kg, IV) caused a pronounced increase in frequency of breathing (Freq), tidal volume (TV) and minute ventilation (MV) in naïve C57BL/6 mice, whereas injection of D-CSNO (50 nmol/kg, IV) elicited minimal responses; (2) L-CSNO elicited minor responses in (a) C57BL/6 mice with bilateral carotid sinus nerve transection (CSNX), (b) C57BL/6 mice treated neonatally with capsaicin (CAP) to eliminate small-diameter C-fibers, and (c) C57BL/6 mice receiving continuous infusion of L-CSNO receptor antagonists, S-methyl-L-cysteine and S-ethyl-L-cysteine (L-SMC + L-SEC, both at 5 μmol/kg/min, IV); and (3) injection of S-nitroso-L-glutathione (L-GSNO, 50 nmol/kg, IV) elicited pronounced ventilatory responses that were not inhibited by L-SMC + L-SEC. Subsequent exposure of naïve C57BL/6 mice to a hypoxic gas challenge (HXC; 10% O, 90% N) elicited pronounced increases in Freq, TV and MV that were subject to roll-off.

The Medical Institutional Repositories in Libraries (MIRL) Symposium: a blueprint designed in response to a community of practice need.

Background: Health sciences libraries in medical schools, academic health centers, health care networks, and hospitals have established institutional repositories (IRs) to showcase their research achievements, increase visibility, expand the reach of institutional scholarship, and disseminate unique content. Newer roles for IRs include publishing open access journals, tracking researcher productivity, and serving as repositories for data sharing. Many repository managers oversee their IR with limited assistance from others at their institution.

Ventilatory responses during and following hypercapnic gas challenge are impaired in male but not female endothelial NOS knock-out mice.

The roles of endothelial nitric oxide synthase (eNOS) in the ventilatory responses during and after a hypercapnic gas challenge (HCC, 5% CO, 21% O, 74% N) were assessed in freely-moving female and male wild-type (WT) C57BL6 mice and eNOS knock-out (eNOS-/-) mice of C57BL6 background using whole body plethysmography. HCC elicited an array of ventilatory responses that were similar in male and female WT mice, such as increases in breathing frequency (with falls in inspiratory and expiratory times), and increases in tidal volume, minute ventilation, peak inspiratory and expiratory flows, and inspiratory and expiratory drives. eNOS-/- male mice had smaller increases in minute ventilation, peak inspiratory flow and inspiratory drive, and smaller decreases in inspiratory time than WT males.

Short-term facilitation of breathing upon cessation of hypoxic challenge is impaired in male but not female endothelial NOS knock-out mice.

Decreases in arterial blood oxygen stimulate increases in minute ventilation via activation of peripheral and central respiratory structures. This study evaluates the role of endothelial nitric oxide synthase (eNOS) in the expression of the ventilatory responses during and following a hypoxic gas challenge (HXC, 10% O, 90% N) in freely moving male and female wild-type (WT) C57BL6 and eNOS knock-out (eNOS-/-) mice. Exposure to HXC caused an array of responses (of similar magnitude and duration) in both male and female WT mice such as, rapid increases in frequency of breathing, tidal volume, minute ventilation and peak inspiratory and expiratory flows, that were subject to pronounced roll-off.

NADPH diaphorase detects S-nitrosylated proteins in aldehyde-treated biological tissues.

NADPH diaphorase is used as a histochemical marker of nitric oxide synthase (NOS) in aldehyde-treated tissues. It is thought that the catalytic activity of NOS promotes NADPH-dependent reduction of nitro-blue tetrazolium (NBT) to diformazan. However, it has been argued that a proteinaceous factor other than NOS is responsible for producing diformazan in aldehyde-treated tissues.

The institutional repository landscape in medical schools and academic health centers: a 2018 snapshot view and analysis.

Objective: This study uses survey research methods to gain a deeper understanding of the institutional repository (IR) landscape in medical schools and academic health centers.

Methods: Members of the Association of Academic Health Sciences Libraries (AAHSL) were surveyed about their IRs. The authors used a mixed-methods approach of a survey and qualitative content analysis to identify common themes.

S-nitrosylation of endothelial nitric oxide synthase impacts erectile function.

Neuronal and endothelial nitric oxide synthases (nNOS and eNOS respectively) play major roles in generating the nitric oxide bioactivity necessary for erectile function. S-nitrosylation has been shown to regulate NOS activity. The presence of S-nitrosylated NOS in the penis and the impact of NOS S-nitrosylation/denitrosylation on erectile function were examined.

Mitochondrial protein S-nitrosation protects against ischemia reperfusion-induced denervation at neuromuscular junction in skeletal muscle.

Deterioration of neuromuscular junction (NMJ) integrity and function is causal to muscle atrophy and frailty, ultimately hindering quality of life and increasing the risk of death. In particular, NMJ is vulnerable to ischemia reperfusion (IR) injury when blood flow is restricted followed by restoration. However, little is known about the underlying mechanism(s) and hence the lack of effective interventions.

Research evaluation support services in biomedical libraries.

Objective: The paper provides a review of current practices related to evaluation support services reported by seven biomedical and research libraries.

Methods: A group of seven libraries from the United States and Canada described their experiences with establishing evaluation support services at their libraries. A questionnaire was distributed among the libraries to elicit information as to program development, service and staffing models, campus partnerships, training, products such as tools and reports, and resources used for evaluation support services.

Phenotype of asthmatics with increased airway S-nitrosoglutathione reductase activity.

S-Nitrosoglutathione is an endogenous airway smooth muscle relaxant. Increased airway S-nitrosoglutathione breakdown occurs in some asthma patients. We asked whether patients with increased airway catabolism of this molecule had clinical features that distinguished them from other asthma patients.

Hemoglobin α/eNOS coupling at myoendothelial junctions is required for nitric oxide scavenging during vasoconstriction.

Objective: Hemoglobin α (Hb α) and endothelial nitric oxide synthase (eNOS) form a macromolecular complex at myoendothelial junctions; the functional role of this interaction remains undefined. To test if coupling of eNOS and Hb α regulates nitric oxide signaling, vascular reactivity, and blood pressure using a mimetic peptide of Hb α to disrupt this interaction.

Approach And Results: In silico modeling of Hb α and eNOS identified a conserved sequence of interaction.

Enhanced non-eupneic breathing following hypoxic, hypercapnic or hypoxic-hypercapnic gas challenges in conscious mice.

C57BL6 mice display non-eupneic breathing and spontaneous apneas during wakefulness and sleep as well as markedly disordered breathing following cessation of a hypoxic challenge. We examined whether (1) C57BL6 mice display marked non-eupneic breathing following hypercapnic or hypoxic-hypercapnic challenges, and (2) compared the post-hypoxia changes in non-eupneic breathing of C57BL6 mice to those of B6AF1 (57BL6 dam × A/J sire) and Swiss-Webster mice, which display different ventilatory responses than C57BL6 mice. C57BL6 mice displayed marked increases in respiratory frequency and non-eupneic breathing upon return to room-air after hypoxic (10% O2, 90% N2), hypercapnic (5% CO2, 21% O2 and 74% N2) and hypoxic-hypercapnic (10% O2, 5% CO2 and 85% N2) challenges.

Morphine has latent deleterious effects on the ventilatory responses to a hypoxic challenge.

The aim of this study was to determine whether morphine depresses the ventilatory responses elicited by a hypoxic challenge (10% O, 90% N) in conscious rats at a time when the effects of morphine on arterial blood gas (ABG) chemistry, Alveolar-arterial (A-a) gradient and minute ventilation (V) had completely subsided. In vehicle-treated rats, each episode of hypoxia stimulated ventilatory function and the responses generally subsided during each normoxic period. Morphine (5 mg/kg, i.

Morphine has latent deleterious effects on the ventilatory responses to a hypoxic-hypercapnic challenge.

This study explored the concept that morphine has latent deleterious actions on the ventilatory control systems that respond to a hypoxic-hypercapnic challenge. In this study, we examined the ventilatory responses elicited by hypoxic-hypercapnic challenge in conscious rats at a time when the effects of morphine (10 mg/kg) on arterial blood-gas chemistry and minute ventilation had subsided. Morphine induced pronounced changes in arterial blood-gas chemistry (e.

Hypoxia-induced changes in protein s-nitrosylation in female mouse brainstem.

Exposure to hypoxia elicits an increase in minute ventilation that diminishes during continued exposure (roll-off). Brainstem N-methyl-D-aspartate receptors (NMDARs) and neuronal nitric oxide synthase (nNOS) contribute to the initial hypoxia-induced increases in minute ventilation. Roll-off is regulated by platelet-derived growth factor receptor-β (PDGFR-β) and S-nitrosoglutathione (GSNO) reductase (GSNOR).

Low-dose morphine elicits ventilatory excitant and depressant responses in conscious rats: Role of peripheral μ-opioid receptors.

The systemic administration of morphine affects ventilation via a mixture of central and peripheral actions. The aims of this study were to characterize the ventilatory responses elicited by a low dose of morphine in conscious rats; to determine whether tolerance develops to these responses; and to determine the potential roles of peripheral μ-opioid receptors (μ-ORs) in these responses. Ventilatory parameters were monitored via unrestrained whole-body plethysmography.

The role of regulatory proteins and S-nitrosylation of endothelial nitric oxide synthase in the human clitoris: implications for female sexual function.

Introduction: During female sexual arousal, clitoral blood flow is controlled by endothelial nitric oxide synthase (eNOS) and its product, nitric oxide (NO). The mechanisms regulating eNOS activity and NO bioavailability in the clitoris are largely unknown.

Aim: To identify proteins involved in regulation of eNOS activity within the clitoris and to evaluate the effects of S-nitrosoglutathione reductase (GSNO-R) and eNOS nitrosylation/denitrosylation on clitoral blood flow.

Essential role of hemoglobin beta-93-cysteine in posthypoxia facilitation of breathing in conscious mice.

When erythrocyte hemoglobin (Hb) is fully saturated with O2, nitric oxide (NO) covalently binds to the cysteine 93 residue of the Hb β-chain (B93-CYS), forming S-nitrosohemoglobin. Binding of NO is allosterically coupled to the O2 saturation of Hb. As saturation falls, the NO group on B93-CYS is transferred to thiols in the erythrocyte, and in the plasma, forming circulating S-nitrosothiols.

Loss of collectrin, an angiotensin-converting enzyme 2 homolog, uncouples endothelial nitric oxide synthase and causes hypertension and vascular dysfunction.

Background: Collectrin is an orphan member of the renin-angiotensin system and is a homolog of angiotensin-converting enzyme 2, sharing ≈50% sequence identity. Unlike angiotensin-converting enzyme 2, collectrin lacks any catalytic domain. Collectrin has been shown to function as a chaperone of amino acid transporters.

Co-activation of μ- and δ-opioid receptors elicits tolerance to morphine-induced ventilatory depression via generation of peroxynitrite.

We determined whether pretreatment with (1) the μ-/δ-opioid receptor (μ-/δ-OR) antagonist, naloxone, (2) the δ1,2-OR antagonist, naltrindole, or (3) the peroxynitrite scavenger, d-penicillamine, affects the development of tolerance to the ventilatory depressant effects of morphine in rats. The injection of morphine in vehicle-pretreated rats decreased minute ventilation predominantly via decreases in tidal volume. Pretreatment with naloxone blunted the responses to morphine whereas pretreatment with naltrindole or d-penicillamine did not.

Hypoxia-induced ventilatory responses in conscious mice: gender differences in ventilatory roll-off and facilitation.

The aim of this study was to compare the ventilatory responses of C57BL6 female and male mice during a 15 min exposure to a hypoxic-hypercapnic (H-H) or a hypoxic (10% O(2), 90% N(2)) challenge and subsequent return to room air. The ventilatory responses to H-H were similar in males and females whereas there were pronounced gender differences in the ventilatory responses during and following hypoxic challenge. In males, the hypoxic response included initial increases in minute volume via increases in tidal volume and frequency of breathing.

Ventilatory responses during and following exposure to a hypoxic challenge in conscious mice deficient or null in S-nitrosoglutathione reductase.

Exposure to a hypoxic challenge increases ventilation in wild-type (WT) mice that diminish during the challenge (roll-off) whereas return to room air causes an increase in ventilation (short-term facilitation, STF). Since plasma and tissue levels of ventilatory excitant S-nitrosothiols such as S-nitrosoglutathione (GSNO) increase during hypoxia, this study examined whether (1) the initial increase in ventilation is due to generation of GSNO, (2) roll-off is due to increased activity of the GSNO degrading enzyme, GSNO reductase (GSNOR), and (3) STF is limited by GSNOR activity. Initial ventilatory responses to hypoxic challenge (10% O(2), 90% N(2)) were similar in WT, GSNO+/- and GSNO-/- mice.