A comparison of the effects of xylometazoline on nasal airflow, and on blood flux as measured by laser Doppler flowmetry

Inflammation, epigenetics, and metabolism converge to cell senescence and ageing: the regulation and intervention

Remarkable progress in ageing research has been achieved over the past decades. General perceptions and experimental evidence pinpoint that the decline of physical function often initiates by cell senescence and organ ageing. Epigenetic dynamics and immunometabolic reprogramming link to the alterations of cellular response to intrinsic and extrinsic stimuli, representing current hotspots as they not only (re-)shape the individual cell identity, but also involve in cell fate decision. This review focuses on the present findings and emerging concepts in epigenetic, inflammatory, and metabolic regulations and the consequences of the ageing process. Potential therapeutic interventions targeting cell senescence and regulatory mechanisms, using state-of-the-art techniques are also discussed.

Effects of Vasoactive Agents and their Antagonists Measured by Acoustic Rhinometry

The purpose of this study was to assess the effects of a agonists on the human nasal mucosa. Volumetric changes in the nasal cavity after application of phenylephrine (PNL), oxymetazoline (OMZ), and epinephrine (EPR) were investigated using acoustic rhinometry. The reactions of the nasal mucosa were extremely modified after pretreatment by α1 and α2 antagonists, phenoxybenzamine (POB) and yohimbine (YOH), and local anesthetic, xylocaine (XLC). Decongestion of the nasal mucosa evoked by α stimulants was considered to originate mainly from the direct activation of α1 receptors. Decongestion of the middle and posterior parts began later than the anterior part and was more gradual because of the time necessary to transport the drug particles to the posterior areas. Contralateral volume changes were probably controlled by the afferent signals from the ipsilateral side of the nose.

The Effect of Topical Xylometazoline on the Mucosal Temperature of the Nasal Septum

Background

The purpose of this study was to determine the short-term influence of the α2-adrenoreceptor agonist xylometazoline on the nasal mucosal temperature.

Methods

Thirty healthy subjects were enrolled into the study. Fifteen of these subjects got xylometazoline and 15 subjects, matched to age, got saline solution as control. A miniaturized thermocouple was used for continuous detection of the septal mucosal temperature without interruption of nasal breathing before and after application of nose spray.

Results

In the anterior nasal segment, the mucosal temperatures before decongestion were significantly higher than after decongestion (p < 0.05). These changes could not be found in the control group after saline solution. The mean end-expiratory mucosal temperatures were significantly higher than the end-inspiratory ones in both study groups (p < 0.005).

Conclusions

The reduction of the nasal mucosal blood flow because of vasoconstriction and the increase of the nasal cavity volume after decongestion with xylometazoline seem to cause a significant decrease of the septal mucosal temperature in the anterior nasal segment. This might be one possible causative factor of the common symptom of the “dry nose” in patients with nasal decongestant abuse.

Comparative evaluation of nasal blood flow and airflow in the decongestant response to oxymetazoline

BACKGROUND

Nasal blood flow (NBF) plays a crucial role in many physiological and pathological processes but its regulation and relation to other rhinological outcomes is poorly understood.

OBJECTIVES

We measured nasal airway patency, nasal blood flow, and subjective and objective measures of decongestion and assessed their reproducibility and responsiveness.

METHODS

19 healthy adults attended twice. A dose-response curve was constructed using doubling doses of oxymetazoline of 25 μg, 50 μg, 100 μg, and 200 μg at 20 minute intervals. Peak nasal inspiratory flow (PNIF) and nasal airway resistance (NAR) were measured at baseline and after each successive dose, NBF using laser Doppler flowmetry at baseline, 50 μg and 200 μg and a decongestion visual analogue scale after the final dose.

RESULTS

After the final dose of oxymetazoline, NBF decreased by a mean (95% CI, P value) of 139.6 (108.3-170.8, P < .001) units and 99.4 (68.1-130.7, P < .001) units, PNIF increased by 48.9 (22.0-75.8, P < .001) L.min-1 and 38.9 (12.0-65.8, P = .003) L.min-1, and NAR decreased by 0.1 (0.02-0.15, P < .001) Pa/s/cm(3) and 0.09 (0.02-0.15, P = .002) Pa.s.cm-3 at the first and second visits respectively. The area under the curve of decongestion was not significantly different between visits for each variable. The standardized response means for the decongestant response were as follows: NBF, 1.41; PNIF, 1.03; and NAR, 0.97.

CONCLUSIONS

Nasal blood flow using laser Doppler flowmetry is a sensitive and reproducible outcome to decongestion with oxymetazoline, similar to nasal patency and symptoms.

CLINICAL TRIALS REGISTRATION

www.clinicaltrials.gov (NCT 00487032).

Techniques d’étude pharmacologique et clinique de l’obstruction nasale : application à la xylométazoline

Nasal obstruction, a prominent feature of rhinitis, may be quantified in humans by haemodynamic techniques (measuring local blood flux), static methods (measuring the geometry of nasal cavities) and dynamic methods (assessing the patency of nasal airways through the measure of resistance to air flow). These methods demonstrated the nasal decongestant activity of xylometazoline in healthy volunteers and rhinitis patients. Controlled double-blind studies established the clinical efficacy of xylometazoline in infectious and allergic (seasonal and perennial) rhinitis versus placebo and in comparison with various reference substances. The effects on nasal epithelium ciliary activity which are observed in vitro are modest and even less pronounced in vivo owing to dilution in situ and protective physiological processes.

Immediate effect of benzalkonium chloride in decongestant nasal spray on the human nasal mucosal temperature

Benzalkonium chloride is a preservative commonly used in nasal decongestant sprays. It has been suggested that benzalkonium chloride may be harmful to the nasal mucosa. Decongestion with the vasoconstrictor xylometazoline containing benzalkonium chloride has been shown to cause a significant reduction of the nasal mucosal temperature. The purpose of the present study was to determine the short-term influence of xylometazoline nasal spray with and without benzalkonium chloride on the nasal mucosal temperature. Healthy volunteers (30) were included in the study. Fifteen volunteers received xylometazoline nasal spray (1.0 mg/mL) containing benzalkonium chloride (0.1 mg/mL) and 15 age-matched subjects, received xylometazoline nasal spray without benzalkonium chloride. Using a miniaturized thermocouple the septal mucosal temperature was continuously measured at defined intranasal detection sites before and after application of the nasal spray. The mucosal temperature values did not significantly differ between the group receiving xylometazoline containing benzalkonium chloride and the group receiving xylometazoline spray without benzalkonium chloride before and after decongestion (P > 0.05). In both study groups septal mucosal temperatures significantly decreased after decongestion (P < 0.05) because of a reduction of the nasal mucosal blood flow following vasoconstriction. This study indicates that benzalkonium chloride itself does not seem to influence nasal blood flow and nasal mucosal temperature in topical nasal decongestants.

The septal mucosa decongests with naphazoline: a study of mucosal dynamics with sonography

A new method using B-mode and power-Doppler-mode (pD) sonography for the investigation of changes in nasal mucosa swelling and perfusion was developed. The effect of naphazoline (0.25 mg/mL) on the nasal mucosa was visualized and recorded in 1-minute intervals in 40 patients. The effect of normal saline solution was studied in 27 healthy volunteers. The decongestant and normal saline were applied by flooding the anterior nasal cavity. A computer program automatically quantified pD color information. Normal saline solution induced a 4.8 +/- 2.4% increase in perfusion (+/- SEM, n.s.) after 5 minutes. In the naphazoline group, changes in stereometry were measured on B-mode-sequences in 24 (60%) and perfusion changes in 24 participants (60%). In 16 of 40 patients (40%), both stereometry and perfusion were analyzed. After 10 minutes, the septum and inferior turbinate mucosa thickness were reduced by 17 +/- 2.8% (p < 0.001) and 25 +/- 2.6% (p < 0.001). Perfusion of the septum and inferior turbinate mucosa as visualized with pD-sonography decreased by 33 +/- 3.3% (p < 0.001). The reduction of bloodflow induced by naphazoline as visualized with pD-sonography is within the range of perfusion changes found in LDF and Xenon clearance studies. Decongestion of the septum mucosa demonstrates erectile properties of the septum, which may contribute to the increase of nasal patency after nasal decongestion.

Studies of spontaneous fluctuations in congestion and nasal mucosal microcirculation and the effects of oxymetazoline using rhinostereometry and micromanipulator guided laser Doppler flowmetry

The mucosa of the inferior turbinate was studied using rhinostereometry and micromanipulator-guided laser Doppler flowmetry in 10 healthy volunteers. First, spontaneous fluctuations were studied measuring congestion and multiple microcirculatory parameters simultaneously every 2 minutes. The subjects were then challenged with oxymetazoline using the same measuring technique studying the effects of the challenge during 12 minutes. There were spontaneous variations in congestion of up to 2.1 mm and variations in perfusion from 38% to 175% of average. There was no correlation between congestion in itself, or change in congestion, to perfusion or any other microcirculatory parameter. After challenge with oxymetazoline there was a rapid decrease in perfusion at 3 minutes after which there were no significant changes. The congestion decreased gradually throughout the procedure. Because congestion reflects the filling of the venous sinusoids and the flowmetry the state of the superficial vessels, we conclude that there are spontaneous short-term fluctuations in the sympathetic tone with independent actions on the different vessels. After challenge with a sympathomimetic drug, there was a decrease in both swelling and flow, but not synchronized. The combination of rhinostereometry and micromanipulator-guided laser Doppler flowmetry is a useful tool to study the dynamics of intranasal challenge reactions.

A comparison of the effects of an alpha-agonist, an anti-muscarinic agent and placebo on intranasal histamine challenge in allergic rhinitis

Autonomic receptors play a part in the physiology and pathology of the nasal mucosa. The effect of an alpha-agonist and an anti-muscarinic agent on histamine-challenge was examined on patients with perennial allergic rhinitis. Nine patients received saline, oxitropium bromide 0.075%, or xylometazoline hydrochloride 0.1% in a double-blind fashion. Sequential challenge with increasing doses of histamine were given and resistance changes, sneezes and volume and content of secretion measured. Histamine challenge produced dose-related increases in nasal resistance (P < 0.0001), lavage fluid volume (P < 0.01) and total protein (P < 0.01). Following xylometazoline, histamine produced little increase in resistance compared with saline and oxitropium bromide (P < 0.0001). The latter reduced the dose-related increase in resistance (P < 0.01) and nasal lavage fluid volume (P = 0.0007) and total protein (P = 0.023) seen with saline. These results confirm the importance of alpha-adrenergic and muscarinic receptors in the human nasal mucosa and suggest mechanisms of action for these drugs in perennial allergic rhinitis.

Autonomic regulation of nasal vessels during changes in body position

The effects of postural changes on nasal airflow and nasal capillary blood flow were investigated in 15 healthy volunteers. Measurements were performed following nasal application of saline solution (control), the alpha-1 receptor antagonist prazosin, the alpha-2 receptor antagonist yohimbine, and after application of both prazosin and yohimbine. Nasal airflow in the control experiments did not significantly differ in the upright (362 +/- 166 ml/s), dorsally recumbent (350 +/- 167 ml/s) and 70 degrees head down position (311 +/- 167 ml/s). Following application of prazosin, nasal airflow was reduced to 223 +/- 121 ml/s in the upright position. Prazosin treatment significantly reduced nasal airflow to 177 +/- 111 ml/s when subjects were placed in dorsally recumbent positions and to 117 +/- 104 ml/s in 70 degrees head down positions (P < 0.001). Following application of yohimbine, nasal airflow remained stable when subjects were turned from upright (348 +/- 165 ml/s) to supine position (352 +/- 186 ml/s), whereas it was reduced to 199 +/- 137 ml/s in the head-down position. Application of both prazosin and yohimbine significantly increased nasal capillary blood flow in laser Doppler flowmetry measurements (P < 0.05). Changes in body position with or without application of the active drugs did not alter nasal capillary blood flow. These findings suggest that nasal congestion due to increased filling pressure in nasal capacitance vessels following postural changes is mainly prevented by alpha-1 adrenergic mechanisms.

A comparison of cocaine vs. lidocaine with oxymetazoline for use in nasal procedures

This study compared the degree of vasoconstriction and anesthesia obtained with cocaine vs. that obtained with a mixture of lidocaine and oxymetazoline (lido/oxy) in healthy, male volunteers. Blood flow was evaluated by laser Doppler flowmetry. Anesthesia was measured with Semmes-Weinstein monofilaments, testing both sensation threshold and pain perception. A greater decrease in blood flow was seen after the administration of lido/oxy than after the administration of cocaine. Pain perception change was not significantly different between treatment groups at 10 minutes after removal of the medication-soaked pledget, but lido/oxy caused a greater decrease in pain perception than cocaine after 50 minutes. No significant difference in sensation threshold change was seen between treatment groups. Lidocaine with oxymetazoline is, therefore, believed to be an effective alternative to cocaine for nasal procedures.

Effect of oxymetazoline on nasal and sinus mucosal blood flow in the rabbit as measured with laser-Doppler flowmetry

The effect of topical oxymetazoline hydrochloride on the blood flow of the nasal and sinus mucosa of the rabbit was measured by laser-Doppler flowmetry. Oxymetazoline, the active component in clinically used nose drops, induced a dose-dependent decrease of the nasal mucosal blood flow. This effect has previously been shown in humans and suggests the presence of alpha 2-adrenoceptors in the nasal mucosa of the rabbit. Doses of oxymetazoline used clinically in humans induced a 50% reduction of blood flow in rabbits. Rhythmic variations in blood flow were seen in 30% of the rabbits after administration of oxymetazoline. Additionally, oxymetazoline induced a dose-dependent decrease of the mucosal blood flow in the maxillary sinus when the drug was applied in the nose. A vasoconstricting effect of oxymetazoline on the arteries penetrating the maxillary sinus ostium is a possible explanation. This can have positive as well as negative consequences on acute sinus infections.

Increased pressure in venous sinusoids during decongestion of rat nasal mucosa induced by adrenergic agonists

The haemodynamic effects of sympathetic agonists causing decongestion of the nasal mucosa have been investigated in rats. Access to mucosa was obtained from the dorsal side through a small cavity drilled in the nasal bone. The pressures in the venous sinusoids and in the interstitial fluid of nasal mucosa were recorded by micropuncture technique. The local red cell flux (LDF) was monitored by laser Doppler flowmetry, and the blood volume in the mucosa was measured by radio-labelled erythrocytes and albumin. In control rats the tissue blood volume was 0.25 +/- 0.03 g (g wet wt)-1. The interstitial fluid pressure (IFP) was 2.4 +/- 0.6 mmHg and the average blood pressure in venous sinusoids (Ps) was 12.8 +/- 2.7 mmHg. After topical application of noradrenaline (NA) the local blood volume was reduced to 0.12 +/- 0.03 g g-1. Ps was increased to 18.0 +/- 4.0 mmHg, whereas IFP was maintained and LDF was reduced to 40.4% of control, indicating a greater rise in post than in presinusoid vascular resistance. Blocking of both alpha 1 and alpha 2-receptors by phentolamine caused a rise in mucosa blood volume and in LDF by 16 and 20% of control, respectively. Ps increased significantly to 15.2 +/- 3.3 mmHg. Specific stimulation or blocking of alpha 1-receptors by phenylephrine or prazosin induced similar or slightly smaller vascular responses than NA or phentolamine. The effects of the specific alpha 2-agonist (clonidine) or antagonist (yohimbine) on rat mucosa were small, indicating a domination of the alpha 1-receptors. Thus, application of NA caused a rise in blood pressure in the venous sinusoids of nasal mucosa. As LDF fell simultaneously, the reduced blood volume must be due to an increased tone in the muscular wall of venous sinusoids.