The Open Nutrition Journal

2008, 2 : 29-36
Published online 2008 April 23. DOI: 10.2174/1874288200802010029
Publisher ID: TONUTRJ-2-29

Hypothalamic Noradrenergic Hyperactivity and Detrimental Bone Status in an Animal Model of Nutritional Growth Retardation

María I. Olivera , Gabriela E. Compagnucci , Cecilia V. Compagnucci , Christian E. Lezón , Patricia Mandalunis , Sandra I. Hope , Liliana G. Bianciotti , Juan C. Elverdin , Rosa M. Alippi , Marcelo S. Vatta and Patricia M. Boyer
Department of Physiology, School of Dentistry, University of Buenos Aires, Argentina.

ABSTRACT

We have studied hypothalamic noradrenergic activity in relation with bone status in a nutritional growth retardation model (ND). Control rats (C) were fed ad libitum. ND received 80% of the diet consumed by C for 4 weeks and later refed ad libitum for 8 weeks. Food restriction induced detrimental effects on body and femur weight and length (P<0.05) and bone biomechanical properties (P<0.001). Thickness of proliferative and hypertrophic zone (µm) of growth plate cartilage and bone volume (%, mean±SE) were 225.96±5.70 v. 280.70±12.52, 95.16±5.81 v. 134.60±9.30, 17.64±3.23 v. 26.80±2.03, respectively (P<0.05); anterior and posterior hypothalamus norepinephrine uptake and release and tyrosine hydroxylase activity (% of control) were 79.05±3.56, 67.00±10.00, 164.26±16.58 and 80.65±5.92, 147.00±1.00, 152.42±9.30, respectively (P<0.05). Thus, impaired biomechanical bone performance in ND could be due, in part, to the increased hypothalamic noradrenergic activity in response to restriction. Normalization of parameters with refeeding suggests no long-term side-effects in undernourished rats.

Keywords:

Nutritional growth retardation, bone status, hypothalamic noradrenergic activity.