l-carnitine enhances and protects the sperm membranes of spermatozoa

Excerpts from the paper suggest that 25 mM of L-carnitine may be the optimal concentration for the beneficial effect.
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l-carnitine enhances the kinematics and protects the sperm membranes of chilled and frozen-thawed Peruvian Paso horse spermatozoa
Cryobiology. 2024 Mar 7:104884. doi: 10.1016/j.cryobiol.2024.104884. Online ahead of print.
Authors
Paula Palacios 1 , Gabriela Peláez 1 , Manuel Soria 1 , Silvana Méndez 1 , Luis Galarza-Álvarez 1 , Jesús Dorado 2 , Julián Santiago-Moreno 3 , Diego A Galarza 4
Affiliations

1 Laboratorio de Biotecnología de la Reproducción Animal, Facultad de Ciencias Agropecuarias, Universidad de Cuenca, EC010205, Cuenca, Ecuador.
2 Veterinary Reproduction Group, Department of Animal Medicine and Surgery, University of Cordoba, 14014, Cordoba, Spain.
3 Departamento de Reproducción Animal, INIA-CSIC, 28040, Madrid, Spain.
4 Laboratorio de Biotecnología de la Reproducción Animal, Facultad de Ciencias Agropecuarias, Universidad de Cuenca, EC010205, Cuenca, Ecuador. Electronic address: andres.galarza@ucuenca.edu.ec.

PMID: 38460835
DOI: 10.1016/j.cryobiol.2024.104884

Abstract

l-carnitine (LC) transports fatty acids to the mitochondria for energy production, reducing lipid availability for peroxidation through β-oxidation. This research examines the effect of LC supplementation to two skimmed milk-based extenders on the cryosurvival of chilled (5ºC) and frozen-thawed Peruvian Paso horse spermatozoa. An initial experiment determined the optimal LC concentration (0, 1, 5, 10, 25, and 50 mM) when added to INRA-96® and UHT (skimmed milk + 6% egg yolk) extenders, using nine ejaculates from three stallions chilled for up to 96 h. Subsequently, the effect of 25 mM LC supplementation (the optimal concentration) on chilling (INRA-96) and freezing (INRA-Freeze®) extenders was evaluated using eight pooled samples from sixteen ejaculates (2 ejaculates/pool) from four stallions. Results indicated that all LC concentrations produced significantly higher values (P<0.05) for kinematic variables (total [TM] and progressive motilities, curvilinear [VCL] and straight-line [VSL] velocity, and beat-cross frequency [BCF]), and the integrity of plasma/acrosome membranes (IPIA) compared to non-supplemented chilled sperm samples for up to 96 h with both extenders. Moreover, the use of 25 mM LC was more efficient (P<0.05) in preserving the post-chilled values of velocity, BCF, and IPIA for the long term than lower LC concentrations (1-10 mM). Post-thaw values of total motility, the amplitude of lateral head displacement (ALH), and IPIA were significantly improved (P<0.05) when INRA-Freeze extender was supplemented with 25 mM LC. In conclusion, supplementation ofl-carnitine to skimmed milk-based extenders enhanced kinematic variables and protected the membrane integrity in chilled and frozen-thawed Peruvian Paso horse spermatozoa.

Keywords: Cryopreservation; Peruvian Paso horse; Spermatozoa; l-carnitine.

Copyright © 2024. Published by Elsevier Inc.
Conflict of interest statement

Declaration of competing interest None of the authors have any conflict of interest to declare.