Testosterone metabolism in the medial basal hypothalamus of the starved male rat.
The conversion of testosterone to estradiol by aromatase and to dihydrotestosterone by 5 alpha-reductase was measured in the medial basal hypothalamus of starved and control male rats. Activities of both enzymes were significantly reduced in starved animals. Aromatase activity was 18.2 +/- 2.3 versus 29.8 +/- 5.7 fmol E2/mg protein/90 min (mean +/- SEM, P less than 0.02) and 5 alpha-reductase was 4.95 +/- 0.35 versus 5.96 +/- 0.30 pmol DHT/mg protein/90 min (P less than 0.02) for starved and control animals respectively. The results indicate that hypothalamic metabolism of testosterone is decreased during starvation. Therefore the increased sensitivity of the T-LH feedback described earlier in starved rats [4] cannot be explained by changes in central testosterone metabolism.
D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000378:metabolism; D000818:Animals; D001141:Aromatase / Q000378:metabolism; D013196:Dihydrotestosterone / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D007033:Hypothalamus, Middle / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013217:Starvation / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism*
D013196:Dihydrotestosterone; D013739:Testosterone; D004958:Estradiol; D001141:Aromatase; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase