Unmodified erythropoietic response to a beta adrenergic agonist in hypothyroid mice.
beta-adrenergic agonists are able to increase erythropoiesis in the polycythemic mouse model by possibly increasing erythropoietin secretion. Since a great deal of evidence indicates that the actions of thyroid hormones and catecholamines are intimately interrelated, the present study was designed to estimate the erythropoietic response to isoproterenol, a very well-known beta-adrenergic agonist, in hypothyroid mice. Adult male CF-1 mice, maintained on a standard rodent chow and water (euthyroid) or 0.1% propylthiouracil (PTU) solution (hypothyroid) ad libitum during 37 days. Plasma T4 concentration was 1.75 +/- 0.25 micrograms/ml in euthyroid and < 1.0 microgram/ml in hypothyroid mice at this time. Mice were transfused with 1.0 ml of packed homologous red cells and the erythropoietic effect of graded doses (50, 500 and 5000 micrograms/kg) were tested by the RBC-59Fe incorporation method. No statistically significant differences (unpaired t test) were found between euthyroid and hypothyroid mice. Hypothyroidism, therefore, does not affect beta-adrenergic agonist-induced erythropoietin secretion in the present experimental conditions.
Barceló
A C
AC
Cátedra de Fisiología, Facultad de Odontología, Universidad de Buenos Aires, Argentina.
Bozzini
C
C
Olivera
M I
MI
Bozzini
C E
CE
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D004920:Erythropoiesis / Q000187:drug effects*; D004921:Erythropoietin; D007037:Hypothyroidism; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D051379:Mice
D000318:Adrenergic beta-Agonists; D004921:Erythropoietin; D007545:Isoproterenol