Protective effect of L‐carnitine on testicular ischaemia–reperfusion injury in rats

Abstract

Testicular torsion is a urological emergency referred to as 'acute scrotum', because inappropriate treatment can lead to male subfertility and infertility. A possible cause of testicular damage is the ischaemia-reperfusion (I/R) injury attributed to oxygen free radicals. L-carnitine, a vitamin-like antioxidant, plays a pivotal role in the maturation of spermatozoa within the reproductive tract. The aim of the present paper was to determine the protective effect of L-carnitine on testicular I/R-induced injury. Thirty-two male rats were divided into 4 groups (n = 8). Testicular torsion was created by rotating the right testis 720 degrees in a clockwise direction. Group 1: sham-operated control; group 2: ischaemia; group 3: I/R; group 4: ischaemia-L-carnitine treatment-reperfusion group. L-carnitine (500 mg kg(-1), intraperitoneally) was administered before 30 min of detorsion in Group 4. After torsion (5 h) and detorsion (5 h), bilateral orchidectomy was performed. The malondialdehyde (MDA) level was evaluated in testes. Histopathologically, Johnsen's spermatogenesis criteria and mean seminiferous tubule diameter (MSTD) measurements were used. Testicular MDA levels were higher in the torsion group compared to the sham-control group (p < 0.05). Detorsion (reperfusion) caused a further increase in MDA levels (p < 0.05). Pretreatment with L-carnitine prevented a further increase in MDA levels (p < 0.05). Histologically, torsion caused some separation among germinal cells in the seminiferous tubules, which became much more prominent in the I/R group but was attenuated with L-carnitine pretreatment. In conclusion, L-carnitine pretreatment may have a protective effect in experimental testicular torsion-detorsion model in rats by its well-known antioxidant potential.

Oxytocin in The Prevention of Injury Due to Testicular Torsion/Detorsion in Rats

“…[31] It has been clearly revealed that reperfusion of the ischemic tissue is associated with oxidative stress. [32] Therefore, treatment by detorsion may further damage the testes. ROS are short-lived reactive molecules having one or more unpaired electrons, rendering them highly unstable and highly reactive.…”

Antioxidant Systems and Oxidative Stress in the Testes

“…17,[55][56][57] In addition, the tissue injury induced by testicular torsion/detorsion can be dramatically alleviated by pretreatment with exogenous antioxidants such as selenium, resveratrol, L-carnitine, caffeic acid phenethyl ester and garlic extract. 17,[57][58][59][60] Finally the enzyme purportedly associated with reperfusion injury, xanthine oxidase, can be inhibited by allopurinol and the latter is known to reduce the testicular damage associated with testicular torsion. 56 Notwithstanding the importance of xanthine oxidase-mediated oxidative stress it should also be noted that neutrophil infiltration into the testes following torsion may represent yet another source of uncontrolled free radical generation responsible for mediating the pathophysiological consequences of temporary testicular ischaemia.…”

“…Typically this model involves the application of antioxidant therapy prior to the creation of a brief period of oxidative stress and subsequent comparison of various testicular attributes (lipid peroxidation, histopathology, DNA damage or antioxidant enzyme status) with sham operated controls ( Table 2). Such analyses have recorded significant protection against oxidative stress for factors as garlic extract, 57 caffeic acid phenethyl ester (CAPE), 60 N-acetyl cysteine, 158 pentoxifylline, 159 erdostein, 160 resveratrol, 58 dexpathenol, 161 L-carnitine 59 and propofol anaesthetic. 162 A variety of antioxidants have also been assessed for their ability to counteract oxidative stress in the testes created by alternative mechanisms.…”

Scientific Opinion on the substantiation of health claims related to L-carnitine and faster recovery from muscle fatigue after exercise (ID 738, 1492, 1493), skeletal muscle tissue repair (ID 738, 1492, 1493), increase in endurance capacity (ID 4305, 4684

“…One animal study examined the effect of L-carnitine on testicular ischaemic reperfusion injury in rats (Dokmeci et al, 2007). The Panel considers that evidence provided in animal studies is not sufficient to predict the occurrence of an effect of L-carnitine consumption on spermatogenesis in humans.…”