Role of free L-carnitine and acetyl-L-carnitine in post-gonadal maturation of mammalian spermatozoa

Jeulin, C.; Lewin, L.

doi:10.1093/humupd/2.2.87

Cited by 184 publications

(153 citation statements)

References 93 publications

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“…However, epididymal spermatozoa would still have experienced a considerable carnitine concentration in the pivalate- treated animals (up to 30 mmol/L) and sperm carnitine content was not reduced by the pivalate treatment, re¯ecting the passive nature of such uptake into spermatozoa from the surrounding¯uid ( Jeulin & Lewin, 1996). Because of water resorption in the distal epididymis, raising the dose of pivalate administered would not be anticipated to decrease epididymal carnitine further, unless serum carnitine was completely eliminated.…”

Section: Discussionmentioning

confidence: 99%

Successful lowering of epididymal carnitine by administration of pivalate to rats

Cooper

Wang²,

Yeung³

et al. 1997

Int J of Andrology

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SummaryThis study was designed to lower the epididymal content of carnitine in male rats and to examine subsequent effects on fertility and sperm motility. As carnitine is transported from serum into the epididymal lumen a method to lower serum carnitine was sought. Administration of 20 mmol/L sodium pivalate in the drinking water for up to 5 weeks substantially lowered serum carnitine (to 20% of control levels within 1 week) and reduced epididymal carnitine content (to 25% of control levels in the proximal and 52% of control in distal regions) within 2 weeks. Carnitine in distal cauda epididymal¯uid was also reduced (to 30% of control levels) but no changes were observed in the sperm carnitine content. The percentage motility and kinematic parameters of spermatozoa released from four epididymal regions and diluted into arti®cial medium were unaltered by the treatment, and all males retained their fertility in mating tests performed at weekly intervals. Increasing the dose of sodium pivalate administered to 60 mmol/L for 2 weeks lowered serum carnitine concentration more but did not further decrease epididymal carnitine content and altered neither sperm motility nor male fertility. The rat epididymis secretes an excessive amount of carnitine into its lumen so that substantially lowering the tissue content does not reduce sperm carnitine or affect their motility or fertilizing ability.

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Section: Discussionmentioning

confidence: 99%

Successful lowering of epididymal carnitine by administration of pivalate to rats

Cooper

Wang²,

Yeung³

et al. 1997

Int J of Andrology

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“…This barrier controls the luminal fluid environment, which is different in composition from the blood plasma (Brooks et al 1974. Carnitine, which is an essential cofactor for fatty acid metabolism, is present in epididymal plasma and spermatozoa at a concentration of 1-63 mM (Marquis & Fritz 1965, Casillas 1972, Hinton et al 1979, Jeulin & Lewin 1996, while the blood plasma concentration is only about 50 mM, and carnitine is believed to play an important role(s) in sperm maturation (Casillas & Chaipayungpan 1979) and motility in the epididymis. Carnitine concentration is reduced in the seminal fluid of infertile patients (Matalliotakis et al 2000), and improvements in sperm motility and viability of spermatozoa can be obtained by treatment with carnitine and acetylcarnitine (Vicari & Calogero 2001).…”

Section: Introductionmentioning

confidence: 99%

Carnitine/organic cation transporter OCTN2-mediated transport of carnitine in primary-cultured epididymal epithelial cells

Kobayashi¹,

Irokawa²,

Maeda³

et al. 2005

Reproduction

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Carnitine is essential for the acquisition of motility and maturation of spermatozoa in the epididymis, and is accumulated in epididymal fluid. In this study, carnitine transport into primary-cultured rat epididymal epithelial cells was characterized to clarify the nature of the transporter molecules involved. Uptake of carnitine by primary-cultured epididymal epithelial cells was time, Na 1 and concentration dependent. Kinetic analysis of carnitine uptake by the cells revealed the involvement of high-and low-affinity transport systems with Km values of 21 mM and 2.2 mM respectively. The uptake of carnitine by the cells was significantly reduced by inhibitors of carnitine/organic cation transporter (OCTN2), such as carnitine analogues and cationic compounds. In RT-PCR analysis, OCTN2 expression was detected. These results demonstrated that the high-affinity carnitine transporter OCTN2, which is localized at the basolateral membrane of epididymal epithelial cells, mediates carnitine supply into those cells from the systemic circulation as the first step of permeation from blood to spermatozoa.Reproduction (

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“…During the passage of sperm from the head to the tail of the epididymis, the carnitine concentration increased significantly (Enomoto et al, 2002;Kobayashi et al, 2007). Therefore, it is believed that the acquisition of sperm movement is synchronized with the increasing concentration of carnitine in those sperms (Jeulin & Lawrence, 1996). The carnitine itself is an energy substrate to support the movement of sperm (Al-Daraji, 2007b).…”

Section: Resultsmentioning

confidence: 99%

Effect of L-carnitine supplementation on drake semen quality

Al-Daraji¹,

Tahir²

2014

SA J. An. Sci.

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This study was conducted to determine the effect on semen quality traits of supplementing the diets of Iraqi drakes with L-carnitine. Forty eight male Iraqi ducks, 30 weeks old, were randomly allocated to four treatments with 12 drakes per treatment group, replicated three times, with four drakes per replicate. The treatment groups consisted of birds fed a diet free of L-carnitine (T 1 , control group); birds fed a diet containing 50 mg L-carnitine/kg diet (T 2 ); birds fed a diet containing 100 mg L-carnitine/kg diet (T 3 ); and birds fed a diet containing 150 mg L-carnitine/kg diet. The drakes were fed the experimental diets only during the experimental period, which lasted three months. The semen quality traits that were investigated were ejaculate volume, mass and individual motility of spermatozoa, spermatocrit, spermatozoa concentration, percentages of dead and abnormal spermatozoa and acrosomal abnormalities. Supplementing the diet of drakes with L-carnitine at the levels of 50 -150 mg/kg diet significantly increased ejaculate volume, spermatocrit, mass and individual motility of spermatozoa, and concentration of spermatozoa, while percentages of dead and abnormal spermatozoa and acrosomal abnormalities were decreased. However, T 4 (150 mg L-carnitine/kg diet) recorded the best results in relation to all semen quality traits included in this study. Dietary supplementation with L-carnitine improved the semen quality of local drakes; therefore L-carnitine can be used as an efficient feed additive to improve the reproductive performance of male ducks.

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Role of free L-carnitine and acetyl-L-carnitine in post-gonadal maturation of mammalian spermatozoa

Cited by 184 publications

References 93 publications

Successful lowering of epididymal carnitine by administration of pivalate to rats

Successful lowering of epididymal carnitine by administration of pivalate to rats

Carnitine/organic cation transporter OCTN2-mediated transport of carnitine in primary-cultured epididymal epithelial cells

Effect of L-carnitine supplementation on drake semen quality

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