Influence of the AT(2) receptor on the L-arginine-nitric oxide pathway and effects of (-)-epicatechin on HUVECs from women with preeclampsia.

Pregnancy is a state of vasodilation mediated by nitric oxide (NO). This vasodilation is impaired in women with preeclampsia, and an alteration in the L-arginine-NO pathway may be a causal factor. The production of NO and arginase activity were investigated in plasma and human umbilical vein endothelial cells (HUVECs) from women with preeclampsia, which were associated with arginase II, eNOS, caveolin, angiotensin 1 and 2 receptor expression (AT1R and AT2R, respectively). The effect of (-)-epicatechin on arginase activity and production of anion superoxide in HUVEC also were investigated. Healthy volunteer non-pregnant (HV), normal pregnant (NP) and preeclamptic (PE) women were recruited for this study. Higher values of nitrite/nitrate (NO(2)/NO(3)) were detected in the plasma from PE women as opposed to HV and NP. Lower arginase activity in PE versus HV or NP women was observed. HUVECs from PE women showed lower values of NO(2)/NO(3), higher activity of arginase and higher expression of AT(1)R and AT(2)R than HUVECS from NP women. Interestingly, arginase activity was associated with AT(2)R stimulation; indeed this activity and the high NADPH (nicotinamide adenine dinucleotide phosphate) oxidase activity in HUVECs from PE women can uncouple the production or inactivation of NO. However, we demonstrated that (-)-epicatechin could lead to a decrease in the activity of both enzymes.

[Insulin resistance index: measurement and potential in human reproduction]. / Indice de resistencia a la insulina: medición y potencial en reproducción humana.

Insulin resistance (IRI) applies to abnormalities of insulin-stimulated glucose metabolism. Biochemical events related to this phenomenon are difficult to search in the absence of overt diabetes mellitus. A simple method to quantify insulin resistance was assessed through the measurement of glucose and insulin (fasting glucose [mmol/L] x fasting insulin [mU/L]/22.5) in patients (n = 50) attending our clinic of human reproduction, including controls (n = 10) and diabetics either unstable or under control (n = 5). Cases with obesity, polycystic ovarian disease, diabetes mellitus, infertility and hypoglycemia showed higher (p = 0.01-0.05) IRI changes, inversely correlated with a decreasing fasting glucose observed in diabetics under treatment with various degrees of control. We conclude that the IRI method used in this work is a reliable estimate of insulin resistance with potential applications for the study of reproductive biology.

[The diurnal rhythm of the arterial pressure in normal pregnancy and in hypertension]. / Ritmo diario de tensión arterial en el embarazo normal y con hipertensión.

An alteration upon the daily rhythm of blood pressure in patients with gestational hypertension has been reported, albeit inconsistently. Hence we have evaluated the daily rhythm of blood pressure in women with normal gestation (n = 100) and with pregnancy associated hypertension (n = 111). In an attempt to delineate a possible etiology of the hypertension, patients were subdivided according to a classification of the American College of Obstetricians and Gynecologists. (Group I. Preeclampsia-eclampsia; group II. Chronic hypertension; group III. Chronic hypertension with superimposed preeclampsia; group IV. Late gestational hypertension). Blood pressure quantitation was made with sphygmomanometer and by different observes. Those with normal pregnancy showed a higher increase in both systolic and diastolic pressure in the morning with a peak at 1200 H, that contrasted with a very low level registered at 2400 H. Altogether the hypertensive group exhibited a loss of rhythm; whereas by group: in I. There was absence of rhythm without a predominant pattern; II. & III. An increase of systolic pressure which was accetuated at 0600 H. group IV. Showed the lowest tensional levels without special characteristics. Through these data, it seems that the central nervous system loses control upon daily regulation of blood pressure in preeclamptic women.