STUDY OF THE POSTNATAL EFFECTS OF CHEMOPREVENTIVE AGENTS ON ETHYLNITROSOUREA-INDUCED TRANSPLACENTAL CARCINOGENESIS IN RATS .2. INFLUENCE OFLOW-MOLECULAR-WEIGHT POLYPEPTIDE FACTORS FROM THE THYMUS, PINEAL-GLAND, BONE-MARROW, ANTERIOR HYPOTHALAMUS, BRAIN CORTEX AND BRAIN WHITE SUBSTANCE

Citation
Va. Alexandrov et al., STUDY OF THE POSTNATAL EFFECTS OF CHEMOPREVENTIVE AGENTS ON ETHYLNITROSOUREA-INDUCED TRANSPLACENTAL CARCINOGENESIS IN RATS .2. INFLUENCE OFLOW-MOLECULAR-WEIGHT POLYPEPTIDE FACTORS FROM THE THYMUS, PINEAL-GLAND, BONE-MARROW, ANTERIOR HYPOTHALAMUS, BRAIN CORTEX AND BRAIN WHITE SUBSTANCE, Carcinogenesis, 17(9), 1996, pp. 1931-1934
Citations number
31
Categorie Soggetti
Oncology
Journal title
ISSN journal
01433334
Volume
17
Issue
9
Year of publication
1996
Pages
1931 - 1934
Database
ISI
SICI code
0143-3334(1996)17:9<1931:SOTPEO>2.0.ZU;2-L
Abstract
The influence of the polypeptide factors extracted from thymus, pineal gland, bone marrow, anterior hypothalamus, brain cortex or brain whit e substance on N-ethyl-N-nitrosourea (ENU)-induced transplacental carc inogenesis was studied in rats, ENU was given to pregnant rats as a si ngle i.v. exposure at a dose of 75 mg/kg body weight on the 21st day o f gestation, The polypeptide factors were given to the offspring as a series of s.c. injections, at a dose of 0.5 mg/rat/day, starting at on e or 2.5 months of age and continuing throughout the whole of post-nat al life, ENU induced tumors of the brain, spinal cord, peripheral nerv es and kidneys in 94-98% of the offspring exposed to the carcinogen, w ith an average number of 2.3-2.6 tumors per rat, and an average surviv al time of 294 days, Post-natal thymus factor or pineal gland factor a dministration was followed by an increase in mean lifespan of similar to 2 months and a significant decrease (P < 0.05) in the total tumor n umber per tumor-bearing rat, as well as the incidence and multiplicity of spinal cord tumors, Pineal gland factor also decreased the inciden ce of peripheral nerve and kidney tumors and their number per tumor-be aring rat. Brain cortex factor and brain white substance factor treatm ent was followed by a decrease in total tumor multiplicity of 1.2- to 3.3-fold, and a decrease in incidence of brain tumors of 10 to 33% per rat in comparison to the controls, Brain cortex factor also decreased the total tumor incidence, At the same time, brain white substance fa ctor administration increased the incidence of peripheral nerve tumors and decreased the mean lifespan, Both bone marrow factor and anterior hypothalamus factor did not have any modifying effects on any of the ENU-induced tumors and mean lifespan. Thus, our results show the possi bility of attenuation of transplacental ENU-induced carcinogenesis wit h post-natal administration of some polypeptide substances.