Novel strategy for dental caries by physiologic dentin regeneration with CPNE7 peptide.

OBJECTIVE: CPNE7-derived functional peptide (CPNE7-DP) has been introduced as a bioactive therapeutics for dentin diseases. CPNE7-DP regenerates tubular dentin on the pulpal side and occlude dentinal tubules. CPNE7-DP was capable to treat dentin hypersensitivity typically associated with dentinal wear at the neck of the tooth. However, the role of CPNE7-DP in another common dentin disease, dental caries, remains uninvestigated. In this study, we evaluated the potential application of CPNE7-DP in dentin caries using an experimental dentin caries model in rats. DESIGN: The stability of CPNE7-DP in caries-like environments including pathologic bacteria of caries or low pH was tested. We established a nutrition-time/hyposalivation-based dental caries rat model by inoculating caries-inducing bacteria and diet for sufficient time. Glycopyrrolate has been treated to induce reversible hyposalivation for accelerating caries progression. Then the tubular dentin regeneration was investigated with histologic methods. Also, modulation of inflammation or autophagy by CPNE7-DP was investigated with marker gene expression in human dental pulp cells (hDPCs) and immunohistochemistry. RESULTS: CPNE7-DP was stable with caries-inducing bacteria and low pH. Establishment of dentin caries was confirmed with radiographic and histologic evaluation. CPNE7-DP regenerated a substantial amount of tubular tertiary dentin and alleviated the pulp inflammation of dentin caries. Under inflammatory conditions, CPNE7-DP reduced the expression of inflammatory cytokines. These phenomena could be the consequence of the modulation of autophagy by CPNE7-DP, which reactivates inflamed odontoblasts. CONCLUSIONS: Overall, CPNE7-DP, which repairs caries through physiological dentin regeneration, might help overcoming the limitations of current restorative caries treatments.

Evaluation of systemic absorption and bronchodilator effect of glycopyrronium bromide delivered by nebulizer or a dry powder inhaler in subjects with chronic obstructive pulmonary disease.

BACKGROUND: Effective bronchodilator therapy depends upon adequate drug deposition in the lung. COPD patients who are unable to administer medications efficiently with conventional inhalers may benefit from the use of a nebulizer device. The aim of this study was to evaluate the systemic bioavailability and bronchodilator response of glycopyrronium bromide (GLY) administered by a novel nebulizer (eFlow® closed system [CS] vibrating membrane nebulizer) or dry powder inhaler (DPI) in subjects with moderate-to-severe chronic obstructive pulmonary disease (COPD). METHODS: In this randomized, open-label, single-dose, five-way crossover study, subjects received a sequence of either 50 µg GLY delivered by eFlow CS nebulizer (GLY/eFlow) or 63 µg GLY delivered by DPI (GLY/DPI), with and without activated charcoal, followed by intravenous infusion of 50 µg GLY with a washout period of 7 days between doses. Endpoints included plasma pharmacokinetics, safety and efficacy. RESULTS: The mean (± SD) baseline predicted forced expiratory volume in 1 s (FEV1) of the 30 subjects who completed the study was 51 ± 15%, with a FEV1/forced vital capacity ratio of 50 ± 11%. Without charcoal, the absolute systemic bioavailability of GLY/eFlow and GLY/DPI were approximately 15 and 22%, respectively. Changes from baseline in FEV1 at 60 min post-dose, without administration of charcoal, were 0.180 L and 0.220 L for GLY/eFlow and GLY/DPI, respectively; FEV1 improvements were similar when charcoal was administered (0.220 L for both GLY/eFlow and GLY/DPI). There were no significant differences in spirometry between the two devices. Fewer subjects administered GLY/eFlow reported adverse events (n = 15) than GLY/DPI (n = 18). CONCLUSIONS: After single doses, GLY/DPI delivered numerically higher peak and steady state levels of drug than did GLY/eFlow. Nebulized GLY produced similar bronchodilation but lower systemic levels of drug than GLY/DPI. Slightly higher number of subjects reported adverse events with GLY/DPI than with GLY/eFlow. Nebulized GLY may offer an effective alternative to patients with COPD not adequately treated with other devices. TRIAL REGISTRATION: NCT02512302 (ClinicalTrials.gov). Registered 28 May 2015.

Identification of Major Esterase Involved in Hydrolysis of Soft Anticholinergic (2R3'R-SGM) Designed From Glycopyrrolate in Human and Rat Tissues.

The glycopyrrolate soft analog, SGM, designed to be easily hydrolyzed into the significantly less active zwitterionic metabolite, SGa, typifies soft drug that reduces systemic side effects (a problem often seen with traditional anticholinergics) following local administration. In this study, hydrolysis of 2R3'R-SGM, the highest pharmacologically active stereoisomer of SGM, was investigated in human and rat tissues. In both species, 2R3'R-SGM was metabolized to 2R3'R-SGa in plasma but was stable in liver and intestine. The half-life of 2R3'R-SGM was found to be 16.9 min and 9.8 min in human and rat plasma, respectively. The enzyme inhibition and stimulation experiments showed that plasma paraoxonase 1 (PON1) is responsible for the hydrolysis of 2R3'R-SGM in humans and rats. The PON1-mediated hydrolysis of 2R3'R-SGM was confirmed in the lipoprotein-rich fractions of human plasma. As PON1 is naturally attached to high-density lipoprotein, it might be absent in topical tissues where 2R3'R-SGM is applied, supporting its local stability and efficacy. The metabolic behavior of 2R3'R-SGM indicates that it is an ideal soft drug to be detoxified as soon as it moves into systemic circulation. Furthermore, the similarity of 2R3'R-SGM metabolism in humans and rats showed that the rat is a suitable animal for preclinical study.

Comparative characterization of lung muscarinic receptor binding after intratracheal administration of tiotropium, ipratropium, and glycopyrrolate.

The aim of the current study was to characterize comparatively the binding of muscarinic receptor in the lung of rats intratracheally administered anticholinergic agents (tiotropium, ipratropium, glycopyrrolate) used clinically to treat chronic obstructive pulmonary disease (COPD) and asthma. Binding parameters of [N-methyl-(3)H]scopolamine methyl chloride ([(3)H]NMS) were determined in tissues (lung, bladder, submaxillary gland) of rats intratracheally administered tiotropium, ipratropium, and glycopyrrolate. The in vitro binding affinity of tiotropium for the receptors was 10-11-fold higher than those of ipratropium and glycopyrrolate. Intratracheal administration of tiotropium (0.6-6.4 nmol/kg) caused sustained (lasting at least 24 h) increase in the apparent dissociation constant (K(d)) for [(3)H]NMS binding in rat lung compared with the control value. Concomitantly, there was a long-lasting decrease in the maximal number of binding sites (B(max)) for [(3)H]NMS. Similary, ipratropium and glycopyrrolate at 7.3 and 7.5 nmol/kg, respectively, brought about a significant increase in K(d) for [(3)H]NMS binding. The effect by ipratropium was observed at 2 h but not 12 h, and that by glycopyrrolate lasted for 24 h. Both agents had little influence on the muscarinic receptors in the bladder and submaxillary gland. The present study provides the first evidence that tiotropium, ipratropium, and glycopyrrolate administered intratracheally in rats selectively bound muscarinic receptors of the lung, and tiotropium and glycopyrrolate had a much longer-lasting effect than ipratropium.

Atropine and glycopyrronium show similar binding patterns to M2 (cardiac) and M3 (submandibular gland) muscarinic receptor subtypes in the rat.

Atropine and glycopyrronium are frequently used for premedication to reduce oral and respiratory secretions and prevent bradycardia. Glycopyrronium is said to have similar antisialagogue effects, but is less likely to cause significant tachycardia than atropine. Different antimuscarinic receptor selectivity patterns could explain the differences. The aim of this investigation was to determine the possible selectivity of glycopyrronium for M2 and M3 muscarinic receptor subtypes. Muscarinic receptor subtypes in Wistar rat ventricle and submandibular gland homogenates were characterized with [3H]-N-methylscopolamine ([3H]-NMS) by ligand binding studies. Inhibition of [3H]-NMS binding by non-labelled compounds showed the following order: in rat ventricle: glycopyrronium > atropine >> otenzepad > hexahydrosiladiphenidol (HHSiD) > pirenzepine; in rat submandibular gland: glycopyrronium > atropine >> HHSiD >> pirenzepine > otenzepad. These were similar to the expected order of frequency of M2 and M3 subtypes, respectively. Glycopyrronium showed similarly high affinities for both M2 (Ki = 1.889 (SEM 0.049) nmol litre-1) and M3 (Ki = 1.686 (0.184) nmol litre-1) subtypes. Glycopyrronium bound to a homogeneous population of binding sites in both tissues and showed no selectivity for M2 or M3 muscarinic receptor subtypes.

beta-Glucuronide and sulfate conjugation of scopolamine and glycopyrrolate.

The metabolism of scopolamine and glycopyrrolate was studied in 11 healthy parturients undergoing cesarean section. After a single intramuscular injection of scopolamine (5 micrograms/kg, n = 7) or glycopyrrolate (6 micrograms/kg, n = 4), the concentrations of the drugs in the urine were determined up to 8-12 h using a radioreceptor assay. This assay measures scopolamine and glycopyrrolate with their possible active metabolites. The effect of beta-glucuronidase and sulfatase incubation on the drug concentrations was also studied. The concentrations of scopolamine and/or its active metabolites were on the average 7 times higher after incubation indicating that beta-glucuronide or sulfate conjugation is an important metabolic pathway for scopolamine. On the contrary, the glycopyrrolate concentrations increased only slightly between 1 and 3 hours after the drug injection. Thus, beta-glucuronide or sulfate conjugation plays only a minor part in the metabolism of glycopyrrolate.

Glycopyrrolate: pharmacology and clinical use.

This is a review of glycopyrrolate whose function in clinical practice is compared with that of atropine.

[Glycopyrrolate (Robinul), a new anticholinergic substance]. / Glycopyrrolat (Robinul), eine neue anticholinergisch wirkende Substanz.

Glycopyrrolate is a quaternary ammonium compound with indications for use similar to those for atropine. Because of the quaternary nature, it is poorly absorbed when taken orally and penetrates neither placental nor blood-brain barriers. When given by the parenteral route, the cardio-vagal blocking action of glycopyrrolate is twice that of atropine while inhibition of salivation is 5-6 times greater. The use of glycopyrrolate for premedication provides a therapeutic margin 2-3 times wider than that of atropine. Glycopyrrolate administered with neostigmine to antagonise the residual neuromuscular blockade of non-depolarising relaxants has advantages over atropine because the pharmacodynamic profile is more suited to that of neostigmine. The abrupt changes in cardiac rate, therefore, become minimal. If glycopyrrolate, 5 micrograms/kg-1, is injected intravenously just before the induction of anaesthesia, severe bradycardia is inhibited when repeated doses of succinylcholine are used. Although the alkalinising effect on gastric secretions has not been substantially verified, glycopyrrolate does provide long lasting bronchodilatation from its blocking action on smooth muscle. Only a few studies with glycopyrrolate in children have yet been published. However, it appears that this drug provides no real advantages over atropine when used in paediatric anaesthesia.

Direct measurement of the anticholinergic activity of a series of pharmacological compounds on the canine and rabbit urinary bladder.

Antimuscarinic therapy is used widely in the treatment of urine storage failure. Examples of antimuscarinic agents used clinically include atropine, propantheline bromide and glycopyrrolate. Other agents used in clinical urology that are believed to act at least in part by antimuscarinic activity include oxybutynin, imipramine and dicyclomine, These studies were designed to determine the relative potency of a variety of agents to compete directly for muscarinic cholinergic receptors isolated from the canine and rabbit urinary bladder. Radio-ligand binding assays for muscarinic receptors were performed with 10 nM 3H-QNB and various concentrations of the drugs under study. Of the agents tested, propantheline bromide, atropine, and glycopyrrolate were the potent muscarinic antagonists/unit of concentration. Oxybutynin and dicyclomine hydrochloride were 30 to 50 times less potent than atropine. Chlorpromazine and desmethylimipramine were approximately 500 times less potent than atropine. As expected, agents such as guanethidine, tranylcypramine and hexamethonium possessed little antimuscarinic activity.