The effect of hypothermia in a rat testicular torsion/detorsion model

Summary Background Testicular torsion is an emergent condition. The protective effect of medical hypothermia in ischemia/reperfusion injury is well defined. Objectives To evaluate the late results of hypothermia through a rat testicular torsion/detorsion model compatible with human testicular torsion. Study design Rats were divided into 5 groups (n = 7): (1)Sham (S) group, (2)T/D group: right testis was torted for 1-h, (3)T/D + H30 group: hypothermia at 4 °C was applied for 30 min before detorsion, (4)T/D + H90 group: hypothermia at 4 °C was applied for a total of 90 min (30 min before and 1-h after detorsion), (5)H group: hypothermia at 4 °C was applied to right testis for 90 min. Testicular diameters at preoperative period and 8th postoperative week were measured. Biochemically, MPO, NO, 3-NT and 4-HNE in testicular tissue and serum levels of NO, PGF 2α, 3-NT, 8-OHdG and 4-HNE were studied. Histopathologic examination and TUNEL assay were also performed. Results Biochemical and macroscopical parameters of both T/D + H30 and T/D + H90 groups were statistically different from group T/D with respect to protective effects of hypothermia. Johnsen's score was also statistically different in group T/D + H90. Discussion Hypothermia can easily be applied with ice bags both in perioperative period. This is the first study evaluating the effect of hypothermia applied postoperatively. Tissue level of protein oxidation marker (3-NT) and serum levels of DNA damage (8-OHdG), lipid peroxidation (4-HNE), protein oxidation (3-NT) and oxidative stress (PGF-2α) markers were measured for the first time. Conclusions Hypothermia has been shown to be macroscopically, biochemically and histopathologically beneficial in the long-term experimental testicular torsion model. Summary Table . Serum Tissue Groups NO (μM/L) PGF 2 α (pg/ml) 3-NT (ng/ml) 8-OHdG (ng/ml) 4-HNE (ng/ml) MPO (U/mg protein wet tissue) NO (μM/mg wet tissue) 3-NT (ng/g wet tissue) 4-HNE (ng/g wet tissue) S 10,62 ± 1,79 29,16 ± 8,40 1,59 ± 0,53 0,62 ± 0,04 1,96 ± 0,61 1,87 ± 0,64 0,13 ± 0,11 7,79 ± 1,25 4,25 ± 0,66 T/D 16,22 ± 1,55a 55,92 ± 12,75a 5,79 ± 1,21a 0,82 ± 0,08a 7,76 ± 7,44a 7,51 ± 3,60a 0,58 ± 0,44a 14,07 ± 3,09a 5,91 ± 0,47a T/D + H30 12,20 ± 1,92b 38,69 ± 5,26b 3,38 ± 1,07b 0,70 ± 0,09b 3,33 ± 0,57b 3,89 ± 0,97b 0,25 ± 0,10b 9,32 ± 1,54b 4,97 ± 0,98b T/D + H90 11,23 ± 2,35c 33,62 ± 6,15c 3,30 ± 0,63c 0,67 ± 0,06c 3,03 ± 091c 3,70 ± 4,33c 0,22 ± 0,05c 7,62 ± 1,12c 4,55 ± 0,67c H 10,90 ± 1,74 29,89 ± 6,21 2,18 ± 0,75 0,65 ± 0,07 2,19 ± 0,86 2,33 ± 1,15 0,16 ± 0,03 7,84 ± 0,85 3,82 ± 0,92 a p  b p  c p