Levels of seminal free L(‐) carnitine in fertile and infertile men

Abstract

Data about the levels of free L-carnitine, an epididymal marker in human semen, are contradictory and unclear, particularly in their relationship to fertility. This can perhaps be explained by the absence of any studies of seminal L-carnitine in a large group of fertile men, and by the lack of consideration of factors influencing its secretion. In this study, free L-carnitine was determined using a spectrophotometric method in deproteinized semen samples from fertile (n = 162) and infertile men without azoospermia (n = 303). Our results can be summarized as follows: Infertile men were found to have significantly lower (P less than 0.001) seminal carnitine levels (755 +/- SD 499 nmoles) compared with fertile men (1010 +/- 570). Percentiles have been calculated for fertile men, and 'normal' values proposed (10th percentile = 390 and 90th percentile = 1830 nmoles). Distribution of the levels of L-carnitine were asymmetric in fertile as well as in infertile men (median: 922 nmoles vs 645). In both groups, a significant increase in carnitine levels was observed with increasing length of abstinence, and a decrease in the ratio of carnitine/days of abstinence. Methodological, physiological and pathological factors which may explain these results are discussed.

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“…Our study observed a mean total carnitine concentration of 60.49 mg/ml. Other researchers observed total carnitine values ranging from 0.2 to 1.3 mM (0.03-0.21 mg/ml) (2,30,31). We measured carnitine by HPLC, using a C 18 column and absorption at 215 nm.…”

The role of food supplementation in the treatment of the infertile couple and for assisted reproduction

“…Acetyl‐L‐carnitine is the prominent carnitine in spermatozoa and its concentration was lower in semen of infertile men (Kohengkul et al. , 1977; Soufir et al. , 1984).…”

La nutraceutiques (alicaments) et compléments alimentaires dans le traitement de l’infertilité masculine

“…La carnitine libre et I'acetyl Lcarnitine jouent un rble important dans la maturation postgonadique des spermatozo'fdes des mammiferes [32], et le quotient acetyle L-carnitine/carnitine etait different dans de spermatozo'fdes de bonne ou de mauvaise qualite [3,22]. L'acetyle L-carnitine est la carnitine dominante dans les spermatozoYdes et sa concentration etait inferieure dans le sperme d'hommes infertiles [36,64]. La concentration de carnitine libre dans le plasma seminal etait en correlation significative avec la concentration et la motilite spermatiques [48], et il a ete possible de stimuler la motilite des spermatozoYdes en ajoutant de racetyle carnitine in vitro [68].…”