[Subchronic exposure to acrylamide affects reproduction and testis endocrine function of rats].
OBJECTIVE
To explore the effect of subchronic exposure to acrylamide on the reproduction and testis endocrine function of rats.


METHODS
Forty healthy adult male SD rats were randomly divided into 4 groups of equal number, exposed to acrylamide at the dose of 0, 4, 10 and 18 mg/(kg x d) respectively for 9 weeks, and then subjected to the determination of the hindlimb landing foot splay, sperm vitality and morphology, the activities of acid phosphatase (ACP) and alkaline phosphatase (ALP) in the testis homogenate, and the levels of testosterone (T) and estradiol (E2) in the serum and testis homogenate. Based on the primary Leydig cell culture models exposed to acrylamide of 0, 0.1, 0.75, 4 and 8 mmol/L, the activity of Leydig cells was measured by the CCK-8 method.


RESULTS
Following acrylamide exposure, the hindlimb landing foot splay increased markedly with dose increase (P < 0.01). The rates of sperm vitality were (6.86 +/- 5.46)%, (65.43 +/- 5.16)%, (60.86 +/- 4.26)% and (46.86 +/- 2.73)% in the exposed groups, significantly lower than in the control (P < 0.01); the rates of abnormal sperm were (39.00 +/- 10.95)%, (35.43 +/- 7.54)%, (45.71 +/- 13.28)% and (56.71 +/- 17.01)%, significantly increased in the 10 and 18 mg/(kg x d) groups (P < 0.05); ACP activities were (82.93 +/- 11.05), (73.52 +/- 8.77), (77.67 +/- 3.04) and (68.56 +/- 3.09) U/g prot, showing a decreasing tendency, while ALP activities were (0.96 +/- 0.15), (1.07 +/- 0.22), (1.12 +/- 0.22) and (0.74 +/- 0.10) U/g prot, displaying a tendency of first increasing and then decreasing. Both ACP and ALP activities were inhibited significantly in the 18 mg/(kg x d) group as compared with the control (P < 0.05). A marked reduction was noted in T levels in the serum, (13.44 +/- 4.76), (7.69 +/- 3.84), (5.23 +/- 1.42) and (1.36 +/- 0.86) ng/ml, as well as in the testis homogenate, (4.95 +/- 1.64), (3.01 +/- 0.76), (2.44 +/- 0.91) and (0.85 +/- 0.49) ng/mg prot, (P < 0.01), but no significant changes were observed in 17beta-E2 levels. After 24 hours exposure to acrylamide, the optical densities were 0.82 +/- 0.06, 0.56 +/- 0.07, 0.44 +/- 0.06, 0.26 +/- 0.03 and 0.45 +/- 0.21, showing an evident inhibition of the activity of Leydig cells at the dose of 0.1, 0.75, 4 and 8 mmol/L (P < 0.01).


CONCLUSIONS
Subchronic exposure to acrylamide could affect the normal development of sperm, cause changes of the activity of some enzymes in the testis and significantly influence hindlimb motor coordination. Acrylamide directly damages Leydig cells and affects the endocrine function of the testis.
Song
Hong-Xiu
HX
Institute of Traditional Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210029, China. xiuhongsong@163.com
Wang
Ran
R
Geng
Zhi-Ming
ZM
Cao
Shao-Xian
SX
Liu
Tie-Zheng
TZ
D000135:Acid Phosphatase / Q000378:metabolism; D020106:Acrylamide / Q000633:toxicity*; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D004822:Epididymis / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D007985:Leydig Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013076:Sperm Count; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D013737:Testis / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013739:Testosterone / Q000097:blood / Q000378:metabolism; D036401:Toxicity Tests, Chronic
D020106:Acrylamide; D013739:Testosterone; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase