title: In vivo patterns of circulating steroids in adult male rats III. Effect of total parenteral nutrition on the diurnal variation of testosterone.
abstract: The in vivo pattern of circulating testosterone (T) during a 24 hr period was investigated in stock-fed and total parenterally nourished (TPN) rats. A diurnal rhythm of T was observed in control rats with highest concentrations occurring during the dark period. The loss of this rhythm in rats maintained on TPN shows that nutritional regimen affects circulating T and overrides the synchronizing effect of the light/dark cycle.
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D008027:Light; D008297:Male; D010288:Parenteral Nutrition; D010289:Parenteral Nutrition, Total; D011863:Radioimmunoassay; D051381:Rats; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone