Effect of estrogen on the expression of galanin mRNA in pituitary tumor-sensitive and tumor-resistant rat strains.
The hypothesis that estrogen-induced pituitary tumors are mediated by the neuropeptide galanin was tested using tumor-resistant (Sprague-Dawley; SD) and tumor-sensitive (Fischer 344; F344) rat strains. Diethylstilbestrol (DES) increased expression of galamin mRNA in both strains after 1, 2, and 4 weeks of treatment and doubled pituitary weights in F344 rats while pituitary weights in SD rats were unchanged by DES treatment. In F344 rats, both the expression of galanin mRNA and pituitary weights increased linearly with the length of DES treatment. In SD rats however, despite increasing levels of galanin mRNA, pituitary weights did not increase. These data indicate that galanin gene expression, by itself, is not sufficient to account for increased pituitary growth. However, our data do not rule out the possibility that galanin has an indirect role in promoting pituitary growth.
Gregg
D W
DW
Department of Biochemistry, University of Wisconsin, Madison 53706, USA.
Galkin
M
M
Gorski
J
J
D000818:Animals; D015152:Blotting, Northern; D004054:Diethylstilbestrol / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D019004:Galanin / Q000187:drug effects / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects; D009929:Organ Size / Q000187:drug effects; D010902:Pituitary Gland / Q000187:drug effects*; D010911:Pituitary Neoplasms / Q000139:chemically induced*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D011916:Rats, Inbred F344; D011919:Rats, Inbred Strains / Q000502:physiology*; D013997:Time Factors
D004967:Estrogens; D012333:RNA, Messenger; D004054:Diethylstilbestrol; D019004:Galanin