Effects of mepartricin, a polyene macrolide antibiotic, on estrogen-induced hyperplastic growth of the dorsolateral prostate and seminal vesicle in immature castrated rats.
OBJECTIVE
To investigate the effects of mepartricin, a polyene macrolide antibiotic, on estrogen-induced hyperplastic prostate and seminal vesicle (SV) growth in castrated rats.


METHODS
Immature rats aged 3 weeks were castrated and left untreated for 1 week. Then, 17beta-estradiol benzoate (E(2)-BA) was subcutaneously injected at a dose of 10 microg/day twice weekly, and mepartricin was orally administered at doses of 2.5, 5 and 10 mg/kg once daily for 3 weeks. The weights and hydroxyproline contents of the prostate and SV, the activity of growth factors (GFs) in the dorsolateral prostate (DLP) and the serum estrogen level were measured. Histological examination of the prostate and SV was also performed.


RESULTS
Mepartricin dose-dependently suppressed the increase in the serum estrogen level, the weights and hydroxyproline contents of the DLP and SV and the elevation of GF activity in the DLP induced by E(2)-BA treatment. Histological examination also revealed that treatment with mepartricin reduced collagen accumulation and thickening of the smooth muscle layer in the DLP and SV, and proliferation of the glandular epithelium in the DLP.


CONCLUSIONS
These results suggest that mepartricin suppresses hyperplastic growth of the DLP and SV induced by estrogen in immature castrated rats, the underlying mechanism being a reduction in the serum estrogen level, thereby suppressing stromal cell proliferation and activation.
Shakuto
Shuji
S
Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Japan. shuji.shakuto@sanofi-aventis.com
Tsuchiya
Eiko
E
D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002369:Castration; D004195:Disease Models, Animal; D004958:Estradiol / Q000031:analogs & derivatives / Q000633:toxicity; D008297:Male; D008613:Mepartricin / Q000494:pharmacology*; D011470:Prostatic Hyperplasia / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012669:Seminal Vesicles / Q000187:drug effects / Q000473:pathology*; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D008613:Mepartricin; C074283:estradiol 3-benzoate; D004958:Estradiol