title: Ovariectomy upregulates expression of estrogen receptors, NOS, and HSPs in porcine platelets.
abstract: Platelets participate in normal and pathological thrombotic processes. Hormone replacement in postmenopausal women is associated with increase risk for thrombosis. However, little is known regarding how platelets are affected by hormonal status. Nitric oxide (NO) modulates platelet functions and is modulated by hormones. Therefore, the present study was designed to determine how loss of ovarian hormones changes expression of estrogen receptors and regulatory proteins for NO synthase (NOS) in platelets. Estrogen receptors (ER alpha and ER beta), NOS, heat shock proteins 70 and 90 (HSP70 and HSP90), caveolin-1, -2, and -3, calmodulin, NOS activity, and cGMP were analyzed in a lysate of platelets from gonadally intact and ovariectomized female pigs. Expression of ER beta and ER alpha receptors, endothelial NOS (eNOS), HSP70, and HSP90 increased with ovariectomy. NOS activity and cGMP also increased; calmodulin was unchanged. Caveolins were not detected. These results suggest that ovarian hormones influence expression of estrogen receptors and eNOS in platelets. Changes in estrogen receptors and NOS could affect platelet aggregation in response to hormone replacement.
authors.affiliation: Department of Surgery and Physiology and Biophysics, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
authors.forename: Muthuvel
authors.initials: M
authors.lastname: Jayachandran
authors.forename: Virginia M
authors.initials: VM
authors.lastname: Miller
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000378:metabolism*; D015153:Blotting, Western; D019556:COS Cells; D002147:Calmodulin / Q000096:biosynthesis; D002460:Cell Line; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D009929:Organ Size; D010052:Ovariectomy; D011960:Receptors, Estrogen / Q000378:metabolism*; D013552:Swine; D015854:Up-Regulation / Q000502:physiology*
chemical_list: D002147:Calmodulin; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D011960:Receptors, Estrogen; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III