Effect of growth hormone-secreting tumors on adipose tissue cellularity in young and mature rats.
Growth hormone, GH1, or growth hormone and prolactin, GH3, secreting tumors were induced in 1 week old female Wistar-Furth rats and 17 week old female Wistar-Furth rats. At 11 or 30 weeks of age the parametrial fat pad (PFP) was weighed and a portion fixed with osmium tetroxide for cell quantitation by a Coulter counter technique. Tumor induction increased the body weight of both young and mature rats by 50 and 100% respectively when compared to age matched controls. Serum GH was elevated about 100 fold in both young and old treated rats when compared to controls. Tumor induction decreased the weight of the PFP in both young and old rats when compared to controls but the effect was only significant in the GH3 tumor bearing rats weights. The PFP made up a much smaller percentage of the body weight in all the treated groups when compared to respective age matched controls. Mean PFP adipocyte number was not affected by treatment or age. Tumor induction decreased the mean diameter and mean volume of adipocytes in both young and old rats of both treatment groups compared to age matched controls. The distribution of adipocytes by cell diameter was shifted toward smaller cells in the tumor-bearing rats. In conclusion, induction of GH1 or GH3 tumors elevated serum GH concentrations, increased body weight and decreased relative fat pad weight but did not affect adipocyte cell number. Hence, the proposed adipogenic function of GH does not appear to function in this model in vivo.
D000273:Adipose Tissue / Q000473:pathology / Q000503:physiopathology*; D000375:Aging; D000818:Animals; D002460:Cell Line; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D010911:Pituitary Neoplasms / Q000378:metabolism* / Q000473:pathology; D051381:Rats
D013006:Growth Hormone