Browsing by Author "Ocaranza, María Paz"

Now showing 1 - 8 of 8
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    Binding and production of insulin-like growth factor-I in rat mammary gland
    (1991) Ocaranza, María Paz
    1. Mammary tissue from pregnant rat presents low and high affinity IGF-I functional receptors. 2. Mammary explants from pregnant and lactating rats secrete IGF-I and its production was related to the developmental stage of the gland. 3. An inverse relationship between IGF-I production and tissue binding capacity was observed.
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    Counter-regulatory renin–angiotensin system in cardiovascular disease
    (2019) Ocaranza, María Paz; Riquelme, Jaime A.; García, Lorena; Jalil Milad, Jorge; Chiong, Mario; Santos, Robson A. S.; Lavandero, Sergio
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    Hipertrofia cardiaca: eventos moleculares y celulares
    (2006) Carreño, Juan Eduardo; Apablaza, Felipe; Ocaranza, María Paz; Jalil, Jorge E.
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    Left cardiac remodelling assessed by echocardiography is associated with rho-kinase activation in long-distance runners
    (Wiley, 2021) Contreras Briceño, Felipe; Vega, Julián; Mandiola, Jorge; Ocaranza, María Paz; Herrera, Sebastián; Salinas, Manuel; Fernández, Rodrigo; Jalil, Jorge E.; Lavandero, Sergio; Chiong, Mario; Godoy, Paz; Castro, Pablo F.; Sitges, Marta; Gabrielli, Luigi
    This single-blind and cross-sectional study evaluated the role of Rho-kinase (ROCK) as a biomarker of the cardiovascular remodelling process assessed by echocardiography in competitive long-distance runners (LDRs) during the training period before a marathon race. Thirty-six healthy male LDRs (37.0 ± 5.3 years; 174.0 ± 7.0 height; BMI: 23.8 ± 2.8;.V O2-peak: 56.5 ± 7.3 mL·kg−1·min−1) were separated into two groups according to previous training level: high-training (HT, n = 16) ≥ 100 km·week−1 and low-training (LT, n = 20) ≥ 70 and < 100 km·week−1. Also, twenty-one healthy nonactive subjects were included as a control group (CTR). A transthoracic echocardiography was performed and ROCK activity levels in circulating leukocytes were measured at rest (48 h without exercising) the week before the race. The HT group showed a higher left ventricular mass index (LVMi) and left atrial volume index (LAVi) than other groups (p < 0.05, for both); also, higher levels of ROCK activity were found in LDRs (HT = 6.17 ± 1.41 vs. CTR = 1.64 ± 0.66 (p < 0.01); vs. LT = 2.74 ± 0.84; (p < 0.05)). In LDRs a direct correlation between ROCK activity levels and LVMi (r = 0.83; p < 0.001), and LAVi (r = 0.70; p < 0.001) were found. In conclusion, in male competitive long-distance runners, the load of exercise implicated in marathon training is associated with ROCK activity levels and the left cardiac remodelling process assessed by echocardiography.
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    Light-induced release of the cardioprotective peptide angiotensin-(1-9) from thermosensitive liposomes with gold nanoclusters
    (2020) Bejarano, Julian; Rojas, Aldo; Ramirez Sagredo, Andrea; Riveros, Ana L.; Morales Zavala, Francisco; Flores, Yvo; Riquelme, Jaime A.; Guzman, Fanny; Araya, Eyleen; Chiong, Mario; Ocaranza, María Paz; Morales, Javier O.; Villamizar Sarmiento, Maria Gabriela; Sanchez, Gina; Lavandero, Sergio; Kogan, Marcelo J.
    Angiotensin-(1-9), a component of the non-canonical renin-angiotensin system, has a short half-life in blood. This peptide has shown to prevent and/or attenuate hypertension and cardiovascular remodeling. A controlled release of angiotensin-(1-9) is needed for its delivery to the heart. Our aim was to develop a drug delivery system for angiotensin-(1-9). Thermosensitive liposomes (LipoTherm) were prepared with gold nanoclusters (LipoThermAuNC) to increase the stability and reach a temporal and spatial control of angiotensin-(1-9) release. Encapsulation efficiencies of nearly 50% were achieved in LipoTherm, reaching a total angiotensin-(1-9) loading of around 180 mu M. This angiotensin-(1-9)-loaded LipoTherm sized around 100 nm and exhibited a phase transition temperature of 43.C. AuNC were grown on LipoTherm and the new hybrid nanosystem showed energy absorption in the near-infrared (NIR) wavelength range. By NIR laser irradiation, a controlled release of angiotensin-(1-9) was achieved from the LipoTherm-AuNC nanosystem. These nanosystems did not show any cytotoxic effect on cultured cardiomyocytes. Biological activity of angiotensin-(1-9) released from the LipoTherm-AuNCbased nanosystem was confirmed using an ex vivo Langendorff heart model.
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    Receptores beta adrenérgicos en linfocitos circulantes de pacientes con insuficiencia cardiaca crónica
    (1990) Guarda E.; Corbalan R.; Lavandero S.; Martínez S.; Ocaranza, María Paz; Sapag-Hagar M.; Casanegra P.; Valenzuela C.
    Severe decompensated chronic heart failure is associated to increased levels of circulating catecholamines and decreased density of myocardial beta-adrenergic receptors. In 14 patients with stable, class II-III heart failure we studied circulating lymphocytes to determine the number of beta adrenergic receptors, the dissociation constant of 3H dihydroalprenolol (kd) and the intracellular content of cyclic AMP (AMPc). Results (mean +/- SEM) were compared to those obtained in 10 healthy controls. The number of beta receptors was significantly decreased (105 +/- 16 vs 185 +/- 24, fmol/mg of membrane protein, p less than 0.01). No differences were found in Kd (1.65 +/- 0.2 vs. 1.36 +/- 0.28 nm) nor the level of AMPc (7.9 +/- 2.1 vs 7.1 +/- 2.9 pmol/mg protein), respectively. The decreased number of beta adrenergic receptors in the circulating lymphocytes may be related to the increased level of circulating catecholamines that have been shown to be present during exercise in these patients.
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    Rho kinase activation and gene expression related to vascular remodeling in normotensive rats with high angiotensin I-converting enzyme levels
    (2007) Rivera, Paulina; Ocaranza, María Paz; Lavandero, Sergio; Jalil Milad, Jorge
    The RhoA/Rho kinase (ROCK) pathway is a new mechanism of remodeling and vasoconstriction. Few data are available regarding ROCK activation when angiotensin I-converting enzyme is high and blood pressure is normal. We hypothesized that ROCK is activated in the vascular wall in normotensive rats with genetically high angiotensin I converting enzyme levels, and it causes increased vascular expression of genes promoting vascular remodeling and also oxidative stress. Aortic ROCK activation, mRNA and protein levels (of monocyte chemoattractant protein-1, transforming growth factor [TGF]-beta(1), and plasminogen activator inhibitor-1 [PAI-1]), NADPH oxidase activity, and O-2(.-) production were measured in normotensive rats with genetically high (Brown Norway [BN]) and low (Lewis) angiotensin-I-converting enzyme levels and in BN rats treated with the ROCK antagonist fasudil (100 mg/kg per day) for 7 days. ROCK activation was 12-fold higher in BN versus Lewis rats (P<0.05) and was reduced with fasudil by 100% (P<0.05). Aortic TGF-beta 1, PAI-1, and monocyte chemoattractant protein-1 mRNA levels were higher in BN versus Lewis rats by 300%, 180%, and 1000%, respectively (P<0.05). Aortic TGF-beta 1, PAI-1, and monocyte chemoattractant protein-1 protein levels were higher in BN versus Lewis rats (P<0.05). Fasudil reduced TGF-beta 1 and PAI-1 mRNA and TGF-beta 1, PAI-1, and monocyte chemoattractant protein-1 protein aortic levels to those observed in Lewis rats. Aortic reduced nicotinamide-adenine dinucleotide phosphate oxidase activity and .O-2(-) production were increased by 88% and 300%, respectively, in BN rats (P<0.05) and normalized by fasudil. In conclusion, ROCK is significantly activated in the aortic wall in normotensive rats with genetically high angiotensin-I-converting enzyme and angiotensin II, and it causes activation of genes that promote vascular remodeling and also increases vascular oxidative stress.
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    Soluble Interleukin-6 Receptor Regulates Interleukin-6-Dependent Vascular Remodeling in Long-Distance Runners
    (Frontiers Media S.A., 2021) Villar Fincheira, Paulina; Paredes, Aaron J.; Hernandez Diaz, Tomas; Norambuena Soto, Ignacio; Cancino Arenas, Nicole; Sanhueza Olivares, Fernanda; Contreras Briceño, Felipe; Mandiola Ovalle, Jorge; Bruneau, Nicole; Garcia, Lorena; Ocaranza, María Paz; Troncoso, Rodrigo; Gabrielli, Luigi; Chiong, Mario
    Little is known about the effects of training load on exercise-induced plasma increase of interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6R) and their relationship with vascular remodeling. We sought to evaluate the role of sIL 6R as a regulator of IL-6-induced vascular remodeling. Forty-four male marathon runners were recruited and allocated into two groups: low-training (LT, <100 km/week) and high-training (HT, >= 100 km/week), 22 athletes per group. Twenty-one sedentary participants were used as reference. IL-6, sIL-6R and sgp130 levels were measured in plasma samples obtained before and immediately after finishing a marathon (42.2-km). Aortic diameter was measured by echocardiography. The inhibitory effect of sIL-6R on IL-6-induced VSMC migration was assessed using cultured A7r5 VSMCs. Basal plasma IL-6 and sIL-6R levels were similar among sedentary and athlete groups. Plasma IL-6 and sIL-6R levels were elevated after the marathon, and HT athletes had higher post-race plasma sIL-6R, but not IL-6, level than LT athletes. No changes in sgp130 plasma levels were found in LT and HT groups before and after running the marathon. Athletes had a more dilated ascending aorta and aortic root than sedentary participants with no differences between HT and LT athletes. However, a positive correlation between ascending aorta diameter and plasma IL-6 levels corrected by training load and years of training was observed. IL-6 could be responsible for aorta dilation because IL-6 stimulated VSMC migration in vitro, an effect that is inhibited by sIL-6R. However, IL-6 did not modify cell proliferation, collagen type I and contractile protein of VSMC. Our results suggest that exercise induces vascular remodeling. A possible association with IL-6 is proposed. Because sIL-6R inhibits IL-6-induced VSMC migration, a possible mechanism to regulate IL-6-dependent VSMC migration is also proposed.