Enantiomeric contributions to methamphetamine's bidirectional effects on basal and fentanyl-depressed respiration in mice

Copyright © 2024 Elsevier Inc. All rights reserved..

RATIONALE: Fentanyl remains the primary cause of fatal overdoses, and its co-use with methamphetamine (METH) is a growing concern. We previously demonstrated that racemic METH can either enhance or mitigate opioid-induced respiratory depression (OIRD) dependent upon whether a low or high dose is administered. The optical isomers of METH, dextromethamphetamine (d-METH) and levomethamphetamine (l-METH), differ substantially in their selectivity and potency to activate various monoamine (MA) receptors, and these pharmacological differences may underlie the bidirectional effects of the racemate. Since it is unknown which of METH's MA receptor mechanisms mediate these respiratory effects, examination of METH's pharmacologically distinct enantiomers may provide insight into treatment targets for OIRD.

METHODS: The two optical isomers of METH, d-METH and l-METH, were tested in adult male mice to determine their effects on basal and fentanyl-depressed respiratory frequency, tidal volume, and minute ventilation (MVb; i.e., respiratory frequency x tidal volume) using whole-body plethysmography.

RESULTS: When tested at dose ranges of 1.0-10 mg/kg, d-METH elevated MVb and l-METH decreased basal MVb. A dose of 30 mg/kg l-METH increased basal MVb. Under fentanyl-depressed conditions, the bidirectional effects of racemic METH were observed with d-METH treatment while l-METH significantly exacerbated OIRD at 1.0 and 3.0 mg/kg.

CONCLUSIONS: d-METH and l-METH differentially contribute to the bidirectional respiratory modulation observed by the racemate, with d-METH exhibiting predominantly stimulatory effects and l-METH exhibiting primarily depressant effects depending on dose.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:238

Enthalten in:

Pharmacology, biochemistry, and behavior - 238(2024) vom: 25. Apr., Seite 173735

Sprache:

Englisch

Beteiligte Personen:

Elder, Harrison J [VerfasserIn]
Walentiny, D Matthew [VerfasserIn]
Beardsley, Patrick M [VerfasserIn]

Links:

Volltext

Themen:

44RAL3456C
Amphetamine
Analgesics, Opioid
CK833KGX7E
Co-use
Fentanyl
Isomer
Journal Article
Methamphetamine
Monoamine receptors
Respiratory depression
UF599785JZ

Anmerkungen:

Date Completed 15.04.2024

Date Revised 25.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.pbb.2024.173735

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM36863664X