Gossypol投与下雄性ラットに対するHCG負荷の影響について

Abstract

Wistar系成熟雄性ratにgossypol acetic acid (GAA)を5 mg/kg/日ならびに10 mg/kg/日, 3週間経口投与, 20 mg/kg/日2週間経口投与を行った.1)全群とも体重の増加は維持されたが, GAA 20 mg/kg/日投与群では対照群に比べ体重の増加率が有意に低下した.また全群とも死亡したratはなかった.2)睾丸重量, 副睾丸重量は各群間に有意差を認めなかった.3) GAA 20 mg/kg/日投与群では血清LH濃度, 血清FSH濃度, 血清testosterone濃度が対照群に比べ有意に低下した.その他の群では変動を認めなかった.4) GAA 20 mg/kg/日投与群ではHCG 500 IU 4日間腹腔内投与後の血清testosterone濃度も有意に低下した.以上からgossypolは下垂体睾丸系に対して抑制作用があり, Leydig細胞に対して下垂体を介すると共に直接に作用することを認めた

The effect of gossypol acetic acid (GAA) on the pituitary-Leydig cell axis was studied. Adult male Wistar rats were administered orally 5 mg/kg/day GAA for three weeks, 10 mg/kg/day GAA for three weeks or 20 mg/kg/day GAA for two weeks. Each group was treated for four days with saline or 500 IU human chorionic gonadotropin intraperitoneally injected. None of the rats died. The mean body weight in each group was increased, but the mean body weight gain in the 20 mg/kg group was significantly lower than that in the controls (p less than 0.01). There was no significant change in the weight of testes or epididymis in any group. The serum level of lactate dehydrogenase, follicle stimulating hormone and testosterone was significantly lower in the animals treated with 20 mg/kg/day GAA for two weeks than in the controls (p less than 0.05). No change was seen in other groups. The serum testosterone level after HCG stimulation (HCG 500 IU intraperitoneal injection for 4 days) was significantly lower in animals treated with 20 mg/kg/day GAA for two weeks (p less than 0.01). GAA is suggested to affect the pituitary-Leydig cell axis and directly inhibit Leydig cell function.