Circadian variations of serum triiodothyronine, thyroxine, corticosterone and lipids in starved rats.
Circadian variation of serum triiodothyronine (T3), thyroxine (T4), corticosterone (B) and lipids was studied in male Wistar rats after one week of the starvation. The animals were adopted to 12:12 h light-dark cycle (lights on from 7.00 to 19.00 h) and tap water was available ad libitum. Blood samples were drawn at 3 h intervals along a 24 h span. The hormone levels were measured by RIA kits, plasma lipids by photometric method. The results were evaluated by cosinor method. The presence of a circadian rhythm of T3 and B was found in control rats. The starvation resulted in changed circadian rhythm of T3 with lower values of mesor and amplitude, and while acrophase shifted from 14.48 to 2.12. In addition, the starvation induced circadian rhythm of T4 with acrophase at 1.00. The circadian rhythm of B showed significantly higher values of mesor and amplitude, while acrophase shifted from 17.42 to 4.06. The concentration of lipids was changed in the animals deprived of food as compared with controls.
Zwirska-Korczala
K
K
Department of Pathophysiology and Clinical Biochemistry, Silesian Academy of Medicine, Zabrze, Poland.
Ostrowska
Z
Z
Kucharzewski
M
M
Marek
B
B
Swietochowska
E
E
Kos-Kudła
B
B
Buntner
B
B
D000818:Animals; D002940:Circadian Rhythm; D003345:Corticosterone / Q000097:blood*; D008055:Lipids / Q000097:blood*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013217:Starvation / Q000097:blood*; D013974:Thyroxine / Q000097:blood*; D014284:Triiodothyronine / Q000097:blood*
D008055:Lipids; D014284:Triiodothyronine; D013974:Thyroxine; D003345:Corticosterone