[Modifying effects of beraprost sodium (TRK-100) on N-methyl-N-nitrosourea (MNU) carcinogenesis in F344 rats].
The potential tumor-promoting effects of beraprost sodium (TRK-100), stable analogue of prostacyclin (PGI2), were investigated in rats pretreated with N-methyl-N-nitrosourea (MNU) which is a potent initiator of tumor development in a variety of organ or tissues. Male F344 rats were initially given injections of MNU (20 mg/kg b.w. i.p.) twice a week for 3 weeks, and then administered drinking water containing 6, 2, 0.7 or 0.2 ppm of beraprost sodium for the next 29 weeks. For comparison, positive control groups received N-propyl-N-nitrosourea (PNU), which is a carcinogen in hematopoietic system and small intestine on F344 rat, at the dose of 200, 50 and 12.5 ppm in their drinking water. Appropriate non-treated controls were also included. Numerous tumors were observed in many organs including the hematopoietic system, digestive tract, nervous system, Zymbal's gland (auditory sebaceous glands) and peritoneal mesothelium. However, no tumor-enhancing effects of beraprost sodium were observed. In contrast, the groups treated with PNU demonstrated increased development of tumors in the tongue, forestomach, large intestine and Zymbal's gland. These results thus indicate that beraprost sodium is not capable of modulating the development of MNU-induced tumors.
Kurata
Y
Y
Daiyu-kai Institute of Medical Science, Aichi, Japan.
Hagiwara
A
A
Tamano
S
S
Shibata
M
M
Tanaka
H
H
Yamada
M
M
Ito
H
H
Fukushima
S
S
D000818:Animals; D002273:Carcinogens; D004067:Digestive System Neoplasms / Q000139:chemically induced; D004357:Drug Synergism; D011464:Epoprostenol / Q000031:analogs & derivatives; D007942:Leukemia, Experimental / Q000139:chemically induced; D008297:Male; D008770:Methylnitrosourea; D009423:Nervous System Neoplasms / Q000139:chemically induced; D009607:Nitrosourea Compounds; D010534:Peritoneal Neoplasms / Q000139:chemically induced; D051381:Rats; D011916:Rats, Inbred F344; D012626:Sebaceous Gland Neoplasms / Q000139:chemically induced
D002273:Carcinogens; D009607:Nitrosourea Compounds; C048081:beraprost; D008770:Methylnitrosourea; C020796:propylnitrosourea; D011464:Epoprostenol