Effects of clofibrate treatment in laying hens.
Expression of peroxisome proliferator-activated receptor-alpha (PPARalpha) has been shown in liver of chicks, but effects of its activation have not yet been investigated. In this study, laying hens were treated with clofibrate, a synthetic PPARalpha agonist, to investigate the effects of PPARalpha activation on liver lipid metabolism. Hens receiving a diet containing 5 g of clofibrate/kg had a lower food intake and higher liver mRNA concentrations of typical PPARalpha target genes (carnitine palmitoyltransferase 1A, acyl-coenzyme A oxidase, bifunctional enzyme, lipoprotein lipase) involved in hepatic mitochondrial and peroxisomal beta-oxidation and plasma triglyceride clearance than control hens that received the same diet without clofibrate (P<0.05). Hens treated with clofibrate also had lower mRNA concentrations of fatty acid synthase, 3-hydroxy-3-methylglutaryl-coenzyme A reductase, and low-density lipoprotein receptor, proteins involved in fatty acid biosynthesis and cholesterol biosynthesis and uptake, than hens fed the control diet (P<0.05). These changes in clofibrate-treated hens were accompanied by reduced liver triglyceride concentrations, strongly diminished very low density triglyceride and cholesterol concentrations (P<0.05), a disturbed maturation of egg follicles, a complete stop of egg production, and a markedly reduced plasma 17-beta-estradiol concentration (P<0.05). In conclusion, it is shown that clofibrate has complex effects on hepatic lipid metabolism in laying hens that mimic PPARalpha activation in mammals, affect maturation of egg follicles, and lead to a stop of egg production. Because clofibrate treatment strongly reduced food intake in the hens, some of these effects (i.e., egg production) may have been due to a low energy and nutrient intake.
König
B
B
Institute of Agricultural and Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, D-06108 Halle (Saale), Germany.
Kluge
H
H
Haase
K
K
Brandsch
C
C
Stangl
G I
GI
Eder
K
K
D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002645:Chickens / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood / Q000378:metabolism; D002994:Clofibrate / Q000494:pharmacology*; D004032:Diet / Q000662:veterinary; D004530:Egg Yolk / Q000737:chemistry / Q000187:drug effects; D004958:Estradiol / Q000097:blood; D005227:Fatty Acids / Q000378:metabolism; D005247:Feeding Behavior / Q000187:drug effects; D005260:Female; D000960:Hypolipidemic Agents / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D010058:Oviposition / Q000187:drug effects / Q000502:physiology*; D047493:PPAR alpha / Q000378:metabolism; D014280:Triglycerides / Q000097:blood / Q000378:metabolism
D005227:Fatty Acids; D000960:Hypolipidemic Agents; D047493:PPAR alpha; D014280:Triglycerides; D004958:Estradiol; D002784:Cholesterol; D002994:Clofibrate