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Biomedical subjects

A Rebolledo

Publications and source records attributed to A Rebolledo.

25 records · Page 2Linked to original sources
PubMed1996

[Insulin, vascular reactivity and hypertension].

Several epidemiological studies have shown that there is a relationship between hyperinsulinemia, insulin resistance and arterial hypertension. Insulin produces sympathetic nervous system stimulation, enhances renal sodium retention and it directly modifies vascular mechanisms involved in both contraction and relaxation of the vascular smooth muscle. These actions of insulin could lead either to elevation or reduction of blood pressure. The absence of vasodilation due to insulin resistance and/or the enhancement of the hypertensive effects due to hyperinsulinemia could be the link between insulin and hypertension.

Animals↗
PubMed1996

[Effect of insulin on contractile response and calcium binding in rat aorta].

UNLABELLED: Insulin affects physiological mechanisms involved in blood pressure regulation, and at the cellular level modifies endothelial and vascular smooth muscle functions underlying the changes in peripheral resistance. We describe the effects of preincubation with insulin (40 microU/ml for 1-2 hs) on the contractile reactivity of intact rat aortic rings and on 45Ca2+ uptake of EGTA-hyperpermeabilized rat aortic segments. Preincubation with insulin did not affect either contractions induced by 1 microM of NA, or their relaxation induced by 10 mM of caffeine. The contractile response to 1 microM of Ang-II (which in rat aorta is endothelium-independent) was stimulated by insulin preincubation resulting in increases of both maximal developed force and velocity of its spontaneous relaxation. The difference in 45Ca2+ uptake between insulin-treated and insulin-untreated aortic segments was greater at 5 minutes than it was at 30 minutes. CONCLUSIONS: Insulin preincubation affects directly the mechanical response of Ang-II stimulated aortic smooth muscle; we suggest that the modification of SR function is one of the mechanisms involved in insulin regulation of cytosolic Ca2+.

Angiotensin II↗
PubMed1992

The influence of social and political violence on the risk of pregnancy complications.

BACKGROUND: Events in Chile provided an opportunity to evaluate health effects associated with exposure to high levels of social and political violence. METHODS: Neighborhoods in Santiago, Chile, were mapped for occurrences of sociopolitical violence during 1985-86, such as bomb threats, military presence, undercover surveillance, and political demonstrations. Six health centers providing prenatal care were then chosen at random: three from "high-violence" and three from "low-violence" neighborhoods. The 161 healthy, pregnant women due to deliver between August 1 and September 7, 1986, who attended these health centers were interviewed twice about their living conditions. Pregnancy complications and labor/delivery information were subsequently obtained from clinic and hospital records. RESULTS: Women living in the high-violence neighborhoods were significantly more likely to experience pregnancy complications than women living in lower violence neighborhoods (OR = 5.0; 95% CI = 1.9-12.6; p less than 0.01). Residence in a high-violence neighborhood was the strongest risk factor observed; results persisted after controlling for several sets of potential confounders. CONCLUSION: Living in areas of high social and political violence increased the risk of pregnancy complications among otherwise healthy women.

Adult↗
PubMedDate not supplied

Non-selective cationic channels (NSCC) in smooth muscle cells from human umbilical arteries.

The aim of our work was to investigate the presence of non-selective cation channels (NSCC) in freshly isolated smooth muscle cells from the human umbilical artery (HUA), one of the vessels involved in fetal-placental circulation. We studied the electrophysiological properties of NSCC using the patch-clamp technique in whole-cell configuration, and their possible role in the contractile state of intact vessels' rings. Recording with a high intracellular Cs(+) solution and a near physiological extracellular saline solution, we found a Gd(3+)-sensitive current (IC(50) = 1.05 microM) with a linear current-voltage relationship showing a reversal potential (E(rev)) of -2.1 +/- 1.2 mV (n =15 cells). La(3+) (100 microM) and Mg(2+) (5 mM) also blocked this current. In such conditions, inward currents were carried by Na(+) and Ca(2+); hence, a Na(+)-free solution inhibited only inward current (-67.3 +/- 11.4%, at -40 mV, n = 7, p < 0.05) and a Ca(2+)-Na(+)-free solution decreased the current even further with respect to values obtained in Na(+)-free solution (-69.8 +/- 8.8% at -40 mV, n = 9, p < 0.05). The permeability ratios (P(X)/P(Cs(+))) for monovalent and divalent cations were 1, 0.9, 0.7, 0.7, 0.7, and 0.5 where X = Cs(+), Na(+), Li(+), Ca(2+), Ba(2+) and Tris(+), respectively. In intact tissue, a 0 Ca(2+) extracellular solution, Gd(3+) (100-250 microM), La(3+) (200 microM) and Mg(2+) (5 mM) induced vasorelaxation in non-stimulated HUA rings.

Cations↗
PubMedDate not supplied

[Evaluation of the Program of the Feeding and Language Stimulation Centers in 3 Chilean regions].

To evaluate the effect of attendance to a non traditional day care center ("CADEL") on physical and psychomotor development, 366 children aged 2-5 years belonging to 22 centers were studied. Weight and height were measured at 0, 4 and 8 months and weight for age, height for age and weight for height indexes were calculated from WHO/NCHS standards. Psychomotor development at the beginning of the study and 8 months latter through a standard test (TEPSI) was evaluated. Mean weight and height monthly increments were 144 +/- 83 g and 0.54 +/- 0.16 cm, 72 and 90% respectively of normal growth. Protein energy malnutrition prevalence (30.8%) was not modified but subnormal values of psychomotor development (40.9%) decreased during the study (p less than 0.05 global, coordination and motor function). Language retardation did not improve with the attendance to the program. These centers represent low cost alternatives to extended coverage of preschool services for low income families. More active family integration and reinforcement of stimulation and educational activities may improve program effectiveness.

Child Day Care Centers↗