Efeitos da dislipidemia materna sobre parâmetros cardiovasculares, respiratórios e metabólicos na prole de ratos

Abstract

Dyslipidemia is a maternal clinical condition difficult to treat and characterized by the presence of oxidative stress. In this work, we investigated the effects of Dyslipidemia during gestation and lactation on cardiorespiratory and metabolic parameters in rat offspring. The protocols have been approved by the CEUA/UFPB (n° 014/2016). Pregnant rats were divided into a control diet Group (CTL, n = 5) and another with dyslipidemic diet (DLP, n = 5) during pregnancy and lactation. Biochemical parameters, such as oral glucose tolerance tests (TOTG), tolerance to insulin (TTI), fasting glucose (GJ), total cholesterol (TC), high lipoprotein (HDL), low (LDL) and very low (VLDL) density and triglycerides (TG). Were measured at the end of lactation in the mothers and babies to 90 days, as well as cardiorespiratory parameters were evaluated by direct measurement of blood pressure (BP), heart rate (HR), and ventilation for full body plethysmography. We measured also the respiratory rate (FR), tidal volume (VT) and ventilation (VE) during a period of basal and after hypercapnic mix (7% CO2) to evaluate the central chemoreflex of potassium cyanide (KCN (0.04%)) for evaluation of the peripheral chemoreflex and hexamethonium (30 mg/kg) for evaluation of sympathetic activity. During registration the basal PA, evaluated the variability of the FC and PA and electrocardiographic parameters electrocardiographic. Finally, we checked the levels of serum malonaldehyde (MDA). The results are express as mean ± e.p.m. and non-paired Student's t was use for comparison of groups. The significance level was set at p 0.05 <. At the end of lactation, DLP rats exhibited Hyperlipidemia compared to CTL group. In addition, DLP rats showed hyperglycemia at TOTG and TTI. The DLP offspring showed low birth weight (p < 0.05) compared to CTL group. To 90 days, glycerides and lipid parameters were similar among the descendants CTL or DLP. In basal conditions, the rats showed high average PA DLP (CTL: 90 ± 5.5 vs. DLP: 121 ± 2.9 mmHg), but without changes in CF, FR, VT and see. In spectral analysis, the mice exhibited increased LF component DLP (CTL: 4.8 ± 0.4 vs. DLP: 9 ± 0.9 mmHg2) and LF/HF ratio (0.13 ± 0.02 vs. CTL: DLP: 0.29 ± 0.007), without changes in HF. With respect to the components of ECG, the intervals were similar between the groups. During hypercapnia, the DLP group exhibited greater response in Δ FR (CTL: 43.5 ± 2.8 vs. DLP: 65.4 ± 4.6 resp/min) and Δ VE (CTL: 710 ± 71 vs DLP: 1061 ± 130 mL/Kg/min), but without modification in Δ VT. After administration of KCN, the mice exhibited pressure responses DLP (CTL: 58.4 ± 3.9 vs. DLP: 86 ± 6.3 mm Hg) and ventilation (CTL: 104 ± 9.1 vs DLP: 158 ± 14.2 resp/min) and without changing the answer bradycardic (CTL: 269 ± 17.4 vs DLP: 252 ± 14.9 bpm). In addition, the rats had higher BP reduction DLP (CTL: 27 ± 2 vs. DLP: 48 ± 4 mmHg) after the effect of hexamethonium, compared to CTL group. These findings were combine with high serum levels of MDA (p < 0.05) in the offspring of mice of mothers DLP. The offspring of male features DLP hypertension in adult life combined with sympathetic hyperactivity and ventilatory responses and autonomics amplified front of hypoxia and hypercapnia.