Disparate effects of colchicine on thyroxine-induced cardiac hypertrophy and adrenoceptor changes.
Short-term (5 days) administration of L-thyroxine (0.1 mg/kg i.p. daily) to adult Sprague-Dawley rats induces a modest degree of cardiac hypertrophy (22% increase in heart weight/body weight ratios) and directionally opposite changes in cardiac adrenoceptors (24% increase in beta-adrenoceptors and 20% decline in alpha 1-adrenoceptors). Pretreatment with colchicine did not affect the ability of L-thyroxine to induce cardiac hypertrophy but prevented its effects on both beta- and alpha 1-adrenoceptors. These results suggest a selective involvement of microtubules in the action of thyroid hormones on the expression of cardiac adrenoceptor genes.
Limas
C
C
Department of Laboratory Medicine, University of Minnesota School of Medicine, Minneapolis.
Limas
C J
CJ
D000818:Animals; D006332:Cardiomegaly / Q000139:chemically induced* / Q000473:pathology; D003078:Colchicine / Q000494:pharmacology*; D006980:Hyperthyroidism / Q000378:metabolism; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D012016:Reference Values; D013974:Thyroxine / Q000494:pharmacology
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D013974:Thyroxine; D003078:Colchicine