Natl Toxicol Program Tech Rep Ser. 1989 Jul;351:1-256.
p-Chloroaniline has a large production volume and is used as a dye intermediate. Toxicology and carcinogenesis studies of p-chloroaniline (greater than 99% pure) were conducted by administering p-chloroaniline hydrochloride in water by gavage to groups of F344/N rats and B6C3F1 mice of each sex for 16 days, 13 weeks, or 2 years. Vehicle controls were given deionized water by gavage. All doses were calculated as p-chloroaniline; the chemical was administered as the hydrochloride after dissolution in water containing molar equivalents of hydrochloric acid. Genetic toxicology studies were conducted in Salmonella typhimurium, mouse L5178Y lymphoma cells, and Chinese hamster ovary (CHO) cells. Hematologic parameters were measured at the end of the 13-week studies and at 6, 12, 18, and 24 months in the 2-year studies. Supplemental studies of the distribution and disposition of p-chloroaniline were conducted in male F344 rats. Sixteen-Day and Thirteen-Week Studies: In the 16-day studies, male and female rats and mice received 25, 50, 100, or 400 mg/kg of body weight. The vehicle controls received deionized water. All rats and mice that received 200 or 400 mg/kg died during the first 6 days of the studies. Some deaths occurred in each of the lower dose groups of mice. Splenic enlargement was observed at necropsy in rats administered 25, 50, or 100 mg/kg. Congestion of the spleen and hemosiderin deposition in the renal cortical tubular epithelial cells were observed at 100 mg/kg in male and female rats. Compound-related lesions in mice included hemosiderosis of the liver Kupffer cells and congestion of the spleen. In the 13-week studies, 10 rats of each sex were administered doses of 0, 5, 10, 20, 40, or 80 mg/kg. All male rats lived to the end of the 13-week studies. One of 10 female rats that received 80 mg/kg died from unknown causes. The final mean body weights of rats that received 80 mg/kg were 16% lower than that of vehicle controls for males and 4% lower for females. In the 13-week studies in mice, 10 animals of each sex were administered doses of 0, 7.5, 15, 30, 60, or 120 mg/kg. Deaths in mice were not related to p-chloroaniline hydrochloride administration. The final mean body weights of dosed and vehicle control mice were similar. In both rats and mice, no chemically related effects on organ weights were observed at necropsy, except for the spleen, which was enlarged as a function of increasing dose. Methemoglobin was increased in dosed groups and resulted in a secondary anemia, the severity of which was dose related. Compound-related lesions observed histologically, including pigmentation (hemosiderin) in the kidney, spleen, and liver and hematopoiesis in the liver and spleen, reflected the response to the hemolytic anemia and methemoglobinemia induced by p-chloroaniline hydrochloride. Based on these results, groups of 50 rats of each sex were administered 2, 6, or 18 mg/kg p-chloroaniline hydrochloride in water by gavage, 5 days per week for 103 weeks. Groups of 50 mice of each sex were administered 3, 10, or 30 mg/kg on the same schedule. Metabolism and Disposition Studies in Rats: The metabolism and disposition studies in F344/N rats showed that metabolic and excretory pathways were not saturated by p-chloroaniline administered orally at doses ranging from 0.3 to 30 mg/kg. p-Chloroaniline was rapidly metabolized and excreted primarily in urine with a half-life of approximately 2 hours. Body Weight and Survival in the Two-Year Studies: Mean body weights of dosed rats were generally within 5% of those of vehicle controls throughout the studies. The survival of the low and mid dose groups of male rats and of the low and high dose groups of female rats was significantly greater than that of the vehicle controls (male: vehicle control, 18/49; low dose, 32/50; mid dose, 32/50; high dose, 21/50; female: 27/50; 39/50; 36/50; 37/50). The increased survival was attributed to the decreased incidences of mononuclear cell leukemia. Mean body weights of high dose male and female mice were generally within 5% of those of vehiclwithin 5% of those of vehicle controls throughout the studies. The survival of the mid dose group of male mice was lower than that of the vehicle controls after week 99 (male: 43/50; 36/50; 29/50; 35/50; female: 39/50; 42/50; 44/50; 41/50). Nonneoplastic and Neoplastic Effects in the Two-Year Studies: Fibrosis of the spleen was increased in dosed male and high dose female rats (male: vehicle control, 3/49; low dose, 11/50; mid dose, 12/50; high dose, 41/50; female: 1/50; 2/50; 3/50; 42/50). Cellular infiltration of lipocytes (fatty metaplasia) was observed in the spleen at increased incidences in high dose rats (male: 0/49; 0/50; 0/50; 24/50; female: 0/50; 0/50; 0/50; 11/50). The incidence of uncommon sarcomas of the spleen in high dose male rats was significantly greater than that in the vehicle controls (fibrosarcomas, osteosarcomas, or hemangiosarcomas, combined: 0/49; 1/50; 3/50; 38/50). Many of these tumors metastasized to one or more sites. In female rats, one fibrosarcoma of the spleen was found in a mid dose animal, and one osteosarcoma of the spleen was found in a high dose animal. The historical incidence of splenic connective tissue sarcomas (all types) in water gavage vehicle controls is 1/298 (0.3%) for male rats and 0/297 for female rats. The historical incidence of hemangiosarcomas in water gavage controls is 0/300 for male rats and 1/297 (0.3%) for female rats. Adrenal medullary hyperplasia was observed at an increased incidence in high dose female rats (4/50; 4/50; 7/50; 24/50). Marginally increased incidences of pheochromocytomas were seen in high dose male (13/49; 14/48; 15/48; 26/49) and female (2/50; 3/50; 1/50; 6/50) rats. The historical incidence of pheochromocytomas in water gavage vehicle control male F344/N rats is 121/299 (40% ± 16%); the historical incidence in water gavage vehicle control female F344/N rats is 20/295 (7% ± 2%). The incidences of mononuclear cell leukemia in dosed male and female rats were lower than those in vehicle controls (male: 21/49; 3/50; 2/50; 3/50; female: 10/50; 2/50; 1/50; 1/50). The incidences of malignant lymphomas in dosed male and female mice were lower than those in vehicle controls (male: 10/50; 3/49; 9/50; 3/50; female: 19/50; 12/50; 5/50; 10/50). Hematologic and methemoglobin measurements were made on blood samples collected from 15 randomly selected male and female rats per dose group at 6, 12, 18, and 24 months. In general, the high dose group at various intervals showed mild hemolytic anemia and dose-related increases in methemoglobin. In rats, compound-related nonneoplastic lesions were seen histopathologically in the bone marrow, spleen, and liver. These lesions included bone marrow hyperplasia, hepatic hemosiderosis, and splenic fibrosis and suggest compound-related effects on the hematopoietic system in general, the erythropoietic system specifically, and mesenchymal cells in the spleen. In male mice, the incidence of hemangiosarcomas of the liver or spleen in high dose male mice was greater than that in the vehicle controls (4/50; 4/49; 1/50; 10/50). The historical incidence of hemangiomas or hemangiosarcomas at all sites (combined) in water gavage vehicle control male B6C3F1 mice is 11/350 (3% ± 3%). The incidences of hepatocellular adenomas or carcinomas (combined) were increased in dosed male mice (11/50; 21/49; 20/50; 21/50), primarily due to increased incidences of hepatocellular carcinomas (3/50; 7/49; 11/50; 17/50). Hepatocellular carcinomas metastasized to the lung in 1/50 vehicle control, 1/49 low dose, 2/50 mid dose, and 9/50 high dose male mice. The historical incidence ofhepatocellular neoplasms in water gavage vehicle controls is 106/347 (31 ± 6%). Genetic Toxicology: p-Chloroaniline was mutagenic in S. typhimurium strains TA98 and TA100 in the presence of exogenous metabolic activation; no increase in revertant colonies was observed in strains TA97, TA1535, or TA1537. p-Chloroaniline induced trifluorothymidine (Tft) resistance in mouse L5178Y lymphoma cells with and without metabolic activation. In cultured CHO cells, treatment with p-chloroaniline produced significant increases in sister chromatid exchanges (SCEs) both with and without metabolic activation (S9); chromosomal aberrations were significantly increased only in the presence of S9. Audit: The data, documents, and pathology materials from the 2-year studies of p-chloroaniline have been audited. The audit findings show that the conduct of the studies is documented adequately and support the data and results given in this Technical Report. Conclusions: Under the conditions of these 2-year water gavage studies, there was clear evidence of carcinogenic activity of p-chloroaniline hydrochloride for male F344/N rats, as indicated by increased incidences of uncommon sarcomas of the spleen. Pheochromocytomas of the adrenal gland may also have been associated with chemical administration. There was equivocal evidence of carcinogenic activity of p-chloroaniline hydrochloride for female F344/N rats, as indicated by the presence of uncommon sarcomas of the spleen in one mid and one high dose animal and the increased incidence of pheochromocytomas of the adrenal gland. There was some evidence of carcinogenic activity of p-chloroaniline hydrochloride for male B6C3F1 mice, as indicated by increased incidences of hepatocellular neoplasms and of hemangiosarcomas of the liver or spleen. There was no evidence of carcinogenic activity of p-chloroaniline hydrochloride for female B6C3F1 mice administered 3, 10, or 30 mg/kg by gavage for 2 years. The incidences of mononuclear cell leukemia in male and female rats and of malignant lymphomas in male and female mice were decreased by administration of p-chloroaniline hydrochloride. Compound-related splenic fibrosis was present in male and female rats. Synonyms: 1-amino-4-chlorobenzene hydrochloride; 4-chlorophenylamine hydrochloride; 4-chlorobenzeneamine hydrochloride
对氯苯胺产量巨大，用作染料中间体。对氯苯胺（纯度大于99%）的毒理学和致癌作用研究是通过将盐酸对氯苯胺溶于水中，经口灌胃给予不同性别的F344/N大鼠和B6C3F1小鼠，给药时间分别为16天、13周或2年。溶剂对照组经口灌胃给予去离子水。所有剂量均以对氯苯胺计算；该化学品在溶于含等摩尔盐酸的水中后以盐酸盐形式给药。在鼠伤寒沙门氏菌、小鼠L5178Y淋巴瘤细胞和中国仓鼠卵巢（CHO）细胞中进行了遗传毒理学研究。在13周研究结束时以及2年研究中的6、12、18和24个月时测量血液学参数。在雄性F344大鼠中进行了对氯苯胺分布和处置的补充研究。
16天及13周研究：在16天研究中，雄性和雌性大鼠及小鼠接受25、50、100或400mg/kg体重的剂量。溶剂对照组接受去离子水。所有接受200或400mg/kg剂量的大鼠和小鼠在研究的前6天内死亡。在小鼠的每个低剂量组中都有一些死亡发生。在给予25、50或100mg/kg剂量的大鼠尸检时观察到脾脏肿大。在给予100mg/kg剂量的雄性和雌性大鼠中，观察到脾脏充血和肾皮质肾小管上皮细胞中的含铁血黄素沉积。与化合物相关的小鼠病变包括肝库普弗细胞含铁血黄素沉着和脾脏充血。在13周研究中，每种性别10只大鼠分别给予0、5、10、20、40或80mg/kg的剂量。所有雄性大鼠存活至13周研究结束。接受80mg/kg剂量的10只雌性大鼠中有1只因不明原因死亡。接受80mg/kg剂量的大鼠最终平均体重，雄性比溶剂对照组低16%，雌性低4%。在小鼠的13周研究中每种性别10只动物分别给予0、7.5、15、30、60或120mg/kg的剂量。小鼠的死亡与给予盐酸对氯苯胺无关。给药组和溶剂对照组小鼠的最终平均体重相似。在大鼠和小鼠中，尸检时除脾脏随剂量增加而肿大外，未观察到与化学物质相关的对器官重量的影响。给药组高铁血红蛋白增加并导致继发性贫血，其严重程度与剂量相关。组织学观察到的与化合物相关的病变，包括肾脏、脾脏和肝脏中的色素沉着（含铁血黄素）以及肝脏和脾脏中的造血，反映了对盐酸对氯苯胺诱导的溶血性贫血和高铁血红蛋白血症的反应。基于这些结果，每种性别50只大鼠经口灌胃给予2、6或18mg/kg盐酸对氯苯胺，每周5天，共103周。每种性别50只小鼠按相同方案给予3、10或30mg/kg。
对F344/N大鼠的代谢和处置研究表明，口服剂量为0.3至30mg/kg的对氯苯胺时，代谢和排泄途径未饱和。对氯苯胺迅速代谢并主要经尿液排泄，半衰期约为2小时。
在整个研究过程中，给药大鼠的平均体重一般在溶剂对照组的5%以内。低剂量和中剂量组雄性大鼠以及低剂量和高剂量组雌性大鼠的存活率显著高于溶剂对照组（雄性：溶剂对照组，18/49；低剂量组，32/50；中剂量组，32/50；高剂量组，21/50；雌性：27/50；39/50；36/50；37/50）。存活率增加归因于单核细胞白血病发病率的降低。高剂量雄性和雌性小鼠的平均体重在整个研究过程中一般在溶剂对照组的5%以内。雄性小鼠中剂量组在第99周后的存活率低于溶剂对照组（雄性：43/50；36/50；29/50；35/50；雌性：39/50；42/50；44/50；41/50）。
给药雄性大鼠和高剂量雌性大鼠脾脏纤维化增加（雄性：溶剂对照组，3/49；低剂量组，11/50；中剂量组，12/50；高剂量组，41/50；雌性：1/50；2/50；3/50；42/50）。在高剂量大鼠中，脾脏中脂肪细胞的细胞浸润（脂肪化生）发生率增加（雄性：0/49；0/50；0/50；24/50；雌性：0/50；0/50；0/50；11/50）。高剂量雄性大鼠脾脏罕见肉瘤的发生率显著高于溶剂对照组（纤维肉瘤、骨肉瘤或血管肉瘤，合计：0/49；1/50；3/50；38/50）。许多这些肿瘤转移到一个或多个部位。在雌性大鼠中，一只中剂量动物出现脾脏纤维肉瘤，一只高剂量动物出现脾脏骨肉瘤。经口灌胃溶剂对照组雄性大鼠脾脏结缔组织肉瘤（所有类型）的历史发生率为1/298（0.3%），雌性大鼠为0/297。经口灌胃对照组中血管肉瘤的历史发生率，雄性大鼠为0/300，雌性大鼠为1/297（0.3%）。高剂量雌性大鼠肾上腺髓质增生发生率增加（4/50；4/50；7/50；24/50）。高剂量雄性（13/49；14/48；15/48；26/49）和雌性（2/50；3/50；1/50；6/50）大鼠中嗜铬细胞瘤的发生率略有增加。经口灌胃溶剂对照组雄性F344/N大鼠中嗜铬细胞瘤的历史发生率为121/299（40%±16%）；经口灌胃溶剂对照组雌性F344/N大鼠中为20/295（7%±2%）。给药雄性和雌性大鼠中单核细胞白血病的发生率低于溶剂对照组（雄性：21/49；3/50；2/50；3/50；雌性：10/50；2/50；1/50；1/50）。给药雄性和雌性小鼠中恶性淋巴瘤的发生率低于溶剂对照组（雄性：10/50；3/49；9/50；3/50；雌性：19/50；12/50；5/50；10/50）。在6、12、18和24个月时，从每个剂量组随机选取15只雄性和雌性大鼠采集血样进行血液学和高铁血红蛋白测量。一般来说，高剂量组在不同时间间隔显示轻度溶血性贫血和与剂量相关的高铁血红蛋白增加。在大鼠中，组织病理学观察到与化合物相关的非肿瘤性病变见于骨髓、脾脏和肝脏。这些病变包括骨髓增生、肝脏含铁血黄素沉着以及脾脏纤维化，提示该化合物总体上对造血系统、特别是红细胞生成系统以及脾脏间充质细胞有相关影响。在雄性小鼠中，高剂量雄性小鼠肝脏或脾脏血管肉瘤的发生率高于溶剂对照组（4/50；4/49；1/50；10/50）。经口灌胃溶剂对照组雄性B6C3F1小鼠所有部位（合计）血管瘤或血管肉瘤的历史发生率为11/350（3%±3%）。给药雄性小鼠肝细胞腺瘤或癌（合计）的发生率增加（11/50；21/49；20/50；21/50），主要是由于肝细胞癌发生率增加（3/50；7/49；11/50；17/50）。肝细胞癌转移至肺部的情况，溶剂对照组雄性小鼠为1/50，低剂量组为1/49，中剂量组为2/50，高剂量组为9/50。经口灌胃溶剂对照组中肝细胞肿瘤的历史发生率为106/347（31±6%）。
在有外源性代谢活化存在的情况下，对氯苯胺在鼠伤寒沙门氏菌TA98和TA100菌株中具有致突变性；在TA97、TA1535或TA1537菌株中未观察到回复菌落增加。对氯苯胺在有或无代谢活化的情况下均可诱导小鼠L5178Y淋巴瘤细胞产生三氟胸苷（Tft）抗性。在培养的CHO细胞中，无论有无代谢活化（S9），用对氯苯胺处理均使姐妹染色单体交换（SCE）显著增加；仅在有S9存在时染色体畸变显著增加。
对氯苯胺两年研究的数据、文件和病理学材料已进行审核。审核结果表明，研究的开展记录充分，支持本技术报告中的数据和结果。
在这些为期两年的经口灌胃研究条件下，有明确证据表明盐酸对氯苯胺对雄性F344/N大鼠具有致癌活性，表现为脾脏罕见肉瘤的发生率增加。肾上腺嗜铬细胞瘤也可能与化学物质给药有关。有可疑证据表明盐酸对氯苯胺对雌性F344/N大鼠具有致癌活性，表现为一只中剂量和一只高剂量动物出现脾脏罕见肉瘤以及肾上腺嗜铬细胞瘤发生率增加。有一些证据表明盐酸对氯苯胺对雄性B6C3F1小鼠具有致癌活性，表现为肝细胞肿瘤以及肝脏或脾脏血管肉瘤的发生率增加。没有证据表明经口灌胃给予2年、剂量为3、10或30mg/kg的盐酸对氯苯胺对雌性B6C3F1小鼠具有致癌活性。给予盐酸对氯苯胺可降低雄性和雌性大鼠中单核细胞白血病的发生率以及雄性和雌性小鼠中恶性淋巴瘤的发生率。雄性和雌性大鼠均出现与化合物相关的脾脏纤维化。
1 - 氨基 - 4 - 氯苯盐酸盐；4 - 氯苯胺盐酸盐；4 - 氯苯胺盐酸盐
