Paredes S R, Fukuda H, Kozicki P A, Rossetti M V, Conti H, Batlle A M
Ecotoxicol Environ Saf. 1986 Dec;12(3):252-60. doi: 10.1016/0147-6513(86)90016-3.
A comparative study on the effect of oral and subcutaneous (sc) or intravenous (iv) administration of S-adenosyl-L-methionine (SAM) in lead poisoning was carried out. SAM was given daily sc (20 mg/kg) and orally (80 mg/kg) to acute lead-intoxicated mice for 20 days. Chronic lead-poisoned patients received SAM, administered intravenously at a daily dose of 12 mg/kg or orally at a dose of 25-30 mg/kg. Independent of the method of administration in either animals or patients, GSH concentration in reduced lead intoxication was increased after SAM dosing. Corresponding blood lead content rapidly decreased and a significant recovery of hepatic and erythrocytic delta-aminolevulinate dehydratase (ALA-D), initially reduced, was clearly produced in the groups receiving SAM, although the response was slightly slower when SAM was given orally. It was found that the bulk of body lead burden was excreted in the feces, showing a peak within the first 24-48 hr and being much greater in animals treated with SAM. In these cases, urinary lead excretion was very low. Lead ALA-D inhibition was also evidenced by elevated urinary excretion of delta-aminolevulinic acid (ALA), porphobilinogen (PBG), and porphyrins. During treatment, precursors and porphyrins elimination declined, reaching normal levels soon after therapy ended. A good correlation between the recovery of both GSH levels and ALA-D activity and decreased lead content was observed.(ABSTRACT TRUNCATED AT 250 WORDS)
开展了一项关于口服、皮下（sc）或静脉内（iv）给予S-腺苷-L-甲硫氨酸（SAM）对铅中毒影响的对比研究。对急性铅中毒小鼠每日皮下给予SAM（20 mg/kg）和口服给予（80 mg/kg），持续20天。慢性铅中毒患者接受SAM治疗，静脉内给药剂量为每日12 mg/kg，或口服给药剂量为25 - 30 mg/kg。无论在动物还是患者中，给药方式如何，给予SAM后，铅中毒减轻时谷胱甘肽（GSH）浓度均升高。相应的血铅含量迅速下降，在接受SAM的组中，最初降低的肝脏和红细胞δ-氨基-γ-酮戊酸脱水酶（ALA-D）明显恢复，不过口服SAM时反应稍慢。发现体内大部分铅负荷通过粪便排出，在最初24 - 48小时内出现峰值，且在接受SAM治疗的动物中排出量更大。在这些情况下，尿铅排泄量非常低。尿中δ-氨基-γ-酮戊酸（ALA）、卟胆原（PBG）和卟啉排泄增加也证明了铅对ALA-D的抑制作用。治疗期间，前体和卟啉的排泄减少，治疗结束后不久恢复到正常水平。观察到GSH水平和ALA-D活性的恢复与铅含量降低之间有良好的相关性。（摘要截选至250词）
