Oncogenic Potential Of Vinyl Bromide During Chronic Inhalation Exposure - Rats. Pathology Report. Volume 1.
Experimental Pathology Laboratories, Inc., Herndon, Virginia, 1979 Apr:101 pages
Pathologic lesions produced by chronic inhalation of vinyl-bromide (593602) was investigated in rats. All tissues from rats exposed to 12 and 18 months were examined histologically. Liver angiosarcoma was seen in both sexes of all dose groups. Occasional angiosarcomas were also found in the lung, spleen, nasal cavity, and mesentery. Incidence of metastasis to the lung was high. Hepatic angiosarcoma comprised of large blood filled cysts surrounded by proliferating neoplastic endothelial cells. Zymbal gland neoplasms occurred in the 1235ppm group in both sexes and in males of 247ppm group. It was either a squamous cell carcinoma or papilloma. Proliferative and neoplastic hepatocytic lesions were found in both sexes in all dose groups but a dose related pattern was not evident. The hepatic neoplasms were either neoplastic nodules or hepatocellular carcinomas. The neoplastic nodules were characterized by proliferation of differential neoplastic hepatocytes which formed discrete nodules while the carcinomas showed proliferation of poorly differentiated neoplastic hepatocytes invading the liver parenchyma. Bronchioalveolar carcinoma occurred in one male rat each from the 1235 and 247ppm group and in one female rat from the 52ppm group. Bronchioalveolar adenoma was found in one male rat in the 247ppm group and one female rat in the 1235ppm group. The incidence of adenomatous hyperplasia in lungs of male rats in the 1235ppm group was higher than controls, while in female rats it was comparable to that of controls. Spontaneous nonexposure related neoplastic proliferative lesions include those of the mammary glands, pituitary, testis, and brain in both control and exposed animals. The author concludes that long term inhalation of vinyl-bromide is carcinogenic to rats.
NIOSH-Contract; Medical-research; Medical-monitoring; Animal-studies; Fumes; Toxic-gases; Hepatotoxicity; Biochemical-analysis; Physiological-measurements; Laboratory-testing;
NTIS Accession No.
Experimental Pathology Laboratories, Inc., Herndon, Virginia, 101 pages