Effect of Specific Estrogens on Prostaglandin Synthesis in Aorta and Thrombocytes of Female Pigeons

Abstract

Abstract

The effect of two major natural estrogens (estrone and 17β-estradiol) on prostaglandin biosynthesis from [¹⁴C]arachidonic acid in thrombocytes and aorta of female pigeons was compared with that of a male sex hormone (testosterone). In the aorta, 17β-estradiol stimulated the synthesis of 6-keto PGF_1α and PGF_2α but markedly reduced the synthesis of PGE₂. Estrone on the other hand stimulated the synthesis of PGE₂. Testosterone stimulated the synthesis of all prostaglandins in the aorta. In the thrombocytes, 17β-estradiol decreased aggregatory response to arachidonic acid and synthesis of thromboxane B₂. Estrone on the other hand increased aggregatory response to arachidonic acid. Testosterone decreased the synthesis of thromboxane B₂. These studies have documented markedly different effects of estrone and 17β-estradiol on prostaglandin metabolism in aorta and thrombocytes of female pigeons. Furthermore, it is suggested that testosterone when administered to female pigeons might cause favorable effects through decrease in (a) plasma lipid levels and (b) the synthesis of thromboxane B₂ in thrombocytes.