Long-term Consequences Of Early Childhood Obesity In The Endothelial And Erectile Function Of Male Rats

The consequences of obesity to endothelial and erectile dysfunction are well documented, however, the consequences of obesity in early childhood in later years are unknown. We hypothesize that early childhood obesity induced by postnatal overfeeding impairs aortic reactivity, erectile function, and blood pressure in prepubertal and adult male rats. At postnatal day (PND) 1, Wistar rats were divided into a normal litter (NL, dams were kept with 5 female and 5 male pups) or small litter (SL, dams were kept with 2 male and 1 female pup). The rats were evaluated at two time points prepubertal (PND 40), and in adulthood (PND 120). Body weight (g) and retroperitoneal adipose tissue (fat pad weight/100g of the body n=9-13) were evaluated. The mean blood pressure (MBP, mmHg n=6-7) was measured in conscious rats by indirect tail-cuff method. Aorta and corpus cavernosum were removed. Vascular function was performed via pin myograph and erectile function via strip myograph. Concentration-response curves to phenylephrine (PE) or acetylcholine (ACh) were performed. Prepubertal SL rats had higher body weight (NL 148±2 vs. SL 185±4, g, p<0.05), and adipose tissue deposition (NL 0.17±0.09 vs. SL 0.32±0.03, p<0.05). SL at PND 120 had higher body weight (NL 419±9 vs SL 462±5, g, p<0.05) and retroperitoneal adipose tissue (NL 1.2±0.9 vs SL 1.6±0.1, p<0.05]), and SL rats presented increased MBP (NL 114.9±0.58 vs SL 120.5±1.20). No changes in endothelium-dependent relaxation were observed in the aorta at PND 40 or 120. However, there was an increase in vascular contractility in SL group at PND 40 (Emax: NL 1.17±0.40 vs SL 1.47±0.06, g, p<0.05). In the corpus cavernosum, the relaxation induced by electrical field stimulation was significantly decreased for all frequencies of stimulation in SL rats at PD120 compared to NL rats (1 Hz: NL 0.77 ± 0.18% vs SL 0.27 ± 0.09%; 4 Hz: NL 2.48 ± 0.26% vs SL 1.36 ± 0.41%; 16 Hz: NL 3.06 ± 0.28% vs SL 2.39 ± 0.53%). Our data suggest that obesity in early childhood can cause long-lasting vascular damage to males that can be associated with erectile dysfunction in adulthood.