Hypothalamic neuropeptide Y levels in weaning offspring of low-protein malnourished mother rats.

Maternal low-protein malnutrition during gestation and lactation (LP) is an animal model frequently used for the investigation of long-term deleterious consequences of perinatal growth retardation. Hypothalamic neuropeptides are decisively involved in the central nervous regulation of body weight and metabolism. We investigated neuropeptide Y (NPY) in distinct hypothalamic nuclei in the offspring of LP mother rats at the end of the critical hypothalamic differentiation period (20th day of life). Weanling LP offspring were underweight (P< 0.001) and hypoinsulinaemic (P< 0.05), while leptin levels were unchanged. NPY was significantly increased in the paraventricular hypothalamic nucleus (PVN) (P< 0.01) and lateral hypothalamic area (P< 0.05) in LP offspring. In contrast, NPY was unchanged in the ventromedial hypothalamic nucleus (VMN). These observations indicate a leptin-independent stimulation of the orexigenic ARC-PVN axis in undernourished LP rats at weaning. Furthermore a disturbed NPYergic regulation of the VMN is suggested, possibly contributing to alterations of the hypothalamic regulation of body weight and metabolism in LP offspring during life. Copyright 2000 Harcourt Publishers Ltd.