Olive oil consumption leads to high monounsaturated fatty acid intake, especially oleic acid, and has been associated with a reduced risk of hypertension. However, the molecular mechanisms and contribution of its different components to lower blood pressure (BP) require further evaluation. Here, we examined whether a synthetic, non-boxidation-metabolizable derivative of oleic acid, 2-hydroxyoleic acid (2-OHOA), can normalize BP in adult spontaneously hypertensive rats (SHRs) and whether its antihypertensive action involves cAMP-dependent protein kinase A (PKA) and Rho kinase, two major regulators of vascular smooth muscle contraction. Oral administration of 2-OHOA to SHRs induced sustained systolic BP decreases in a time-dependent

Prolactin may be involved in AP-induced weight gain, particularly in men. Future studies should characterize the period of maximal prolactin impact on body weight during AP treatment. Specific populations particularly sensitive to hyperprolactinemia might be identified as well. The negative correlation between prolactin and BMI detected in AP-treated women resembles the dampened prolactin response observed in severe primary obesity.

Purified testicular and ovarian luteinizing hormone/human chorionic gonadotropin (hCG) receptors are phosphorylated at serine and threonine residues by the catalytic subunit of the cAMP-dependent protein kinase (protein kinase A). Occupancy of the receptors by hCG significantly increased the rate but not the extent of phosphorylation. However, prolonged preincubation of receptors with hCG reduced the subsequent rate of receptor phosphorylation. Identical phosphopeptide maps were obtained for the phosphorylated ovarian and testicular receptors. The phosphorylated receptor, like the native receptor, bound to wheat germ lectin and hCG-Sepharose and migrated as a single band of Mr 90,000 (testis) and Mr 85,000 (ovary) on NaDodSO4/PAGE.Neuraminidase treatment of receptors caused reductions of molecular weight to 82,000 (testis) and 77,000 (ovary), and further treatment with O-Glycanase had mnimal effect on molecular size. However, deglycosylation with N-Glycosidase and endoglycosidase F produced a single labeled polypeptide of Mr 59,000 for both gonadal receptors. Treatment of native receptors with neuraminidase caused no apparent change in binding of gonadotropin to blotted receptors, whereas deglycosylated receptors showed a major reduction in hormone binding. These results indicate that luteinizing hormone/hCG receptors are sialoglycoproteins with predominantly N-linked glycosyl residues that account for the size difference between testicular and ovarian receptors and that may participate in the interaction with gonadotropin. Receptor occupancy by agonist leads to a conformational change that facilitates its phosphorylation during initial binding and reduces the rate of phosphorylation after more prolonged exposure to hCG.The luteinizing hormone (lutropin, LH) receptor from rat testis and ovary has been purified by sequential steps of affinity-column chromatography and demonstrated to be a single protein species that binds LH and human chorionic gonadotropin (hCG) (1, 2). The purified LH/hCG receptor has been shown to be a substrate for phosphorylation by cAMP-dependent protein kinase (protein kinase A) (2). The phosphorylated receptor retains its binding affinity for 125I_ labeled hCG and can be employed for structural studies when only minute quantities of receptor protein are available for analysis.Detailed structural characterization of the receptor will be essential to understanding the mechanism of action of gonadotropins. Also, it is conceivable that glycosylation is responsible for the size differences observed for LH/hCG receptors from testis and ovary (1,2 Phosphorylation of Receptor. The solubilized ovarian and testicular receptors were purified to electrophoretic homogeneity and phosphorylated as described (1, 2). Briefly, 1 pmol of purified receptor was added, either directly or after preincubation with hCG, to a reaction mixture containing 1 unit of catalytic subunit of protein kinase A, 10 mM Tris HCI, 10 mM MgCl2, 0.3 mM dithiothreitol, and 10 ,uM [y-32P]ATP (final pH, 7.4). The phosphoryla...

An estrogen binding protein for estradiol-17beta is present in the liver cytosol of female intact and one day oophorectomized rats. The dissociation constant reveals high affinity binding (Kd: 0.69 +/- 0.14 times 10(-10) M). Quantitation of EBP using a dextran-coated charcoal method shows that this specific macromolecular binding is much less than in the rat uterus, but similar to that in DMBA-induced mammary tumors. Sucrose density gradient analysis shows sedimentation at 8-9 S and 4-5 S when compared to bovine serum albumin.

La reproducción total o parcial de este artículo se podrá hacer si el ITAM otorga la autorización previamente por escrito. ©ITAM Derechos Reservados. La reproducción total o parcial de este artículo se podrá hacer si el ITAM otorga la autorización previamente por escrito.