Impaired Ischemia-Reperfusion Responses in the Hearts of Aged Male and Female Offspring of Obese Rats.

Maternal obesity predisposes offspring (F1) to cardiovascular disease. To evaluate basal heart function and ischemia-reperfusion (IR) responses in F1 males and females of obese mothers, female Wistar rats (F0) were fed chow or an obesogenic (MO) diet from weaning through pregnancy and lactation. Non-sibling F1 males and females were weaned to chow at postnatal day (PND) 21 and euthanized at PND 550. Offspring of MO mothers (MOF1) rarely survive beyond PND 650. Hearts were immediately isolated from euthanized F1s and subjected to 30 min ischemia with 20 min reperfusion. Retroperitoneal fat, serum triglycerides, glucose, insulin, and insulin resistance were measured. Baseline left ventricular developed pressure (LVDP) was lower in male and female MOF1 than in controls. After global ischemia, LVDP in control (C) male and female F1 recovered 78 and 83%, respectively, while recovery in MO male and female F1 was significantly lower at 28 and 52%, respectively. Following the IR challenge, MO hearts showed a higher functional susceptibility to reperfusion injury, resulting in lower cardiac reserve than controls in both sexes. Female hearts were more resistant to IR. Retroperitoneal fat was increased in male MOF1 vs. CF1. Circulating triglycerides and insulin resistance were increased in male and female MOF1 vs. CF1. These data show that MO programming reduces F1 cardiac reserve associated with age-related insulin resistance in a sex-specific manner.

Programming Mechanism of Adipose Tissue Expansion in the Rat Offspring of Obese Mothers Occurs in a Sex-Specific Manner.

We investigated whether excessive retroperitoneal adipose tissue (AT) expansion programmed by maternal obesity (MO) affects adipocyte size distribution and gene expression in relation to adipocyte proliferation and differentiation in male and female offspring (F1) from control (F1C) and obese (F1MO) mothers. Female Wistar rats (F0) ate a control or high-fat diet from weaning through pregnancy and lactation. F1 were weaned onto a control diet and euthanized at 110 postnatal days. Fat depots were weighed to estimate the total AT. Serum glucose, triglyceride, leptin, insulin, and the insulin resistance index (HOMA-IR) were determined. Adipocyte size and adipogenic gene expression were examined in retroperitoneal fat. Body weight, retroperitoneal AT and adipogenesis differed between male and female F1Cs. Retroperitoneal AT, glucose, triglyceride, insulin, HOMA-IR and leptin were higher in male and female F1MO vs. F1C. Small adipocytes were reduced in F1MO females and absent in F1MO males; large adipocytes were increased in F1MO males and females vs. F1C. Wnt, PI3K-Akt, and insulin signaling pathways in F1MO males and Egr2 in F1MO females were downregulated vs. F1C. MO induced metabolic dysfunction in F1 through different sex dimorphism mechanisms, including the decreased expression of pro-adipogenic genes and reduced insulin signaling in males and lipid mobilization-related genes in females.