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Home List of Titles Central administration of leptin to ovariectomized ewes inhibits food intake without affecting the secretion of hormones from the pituitary gland: evidence for a dissociation of effects on appetite and neuroendocrine function
Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/210280
- Central administration of leptin to ovariectomized ewes inhibits food intake without affecting the secretion of hormones from the pituitary gland: evidence for a dissociation of effects on appetite and neuroendocrine function
- Henry, Belinda A.; Goding, James W.; Alexander, Warren S.; Tilbrook, Alan J.; Canny, Benedict J.; Dunshea, Frank; Rao, Alexandra; Mansell, Ashley; Clarke, Iain J.
- We have studied the effect of leptin on food intake and neuroendocrine function in ovariectomized ewes. Groups (n = 5) received intracerebroventricular infusions of either vehicle or leptin (20μ g/h) for 3 days and were blood sampled over 6 h on days −1, 2, and for 3 h on day 3 relative to the onset of the infusion. The animals were then killed to measure hypothalamic neuropeptide Y expression by in situ hybridization. Plasma samples were assayed for metabolic parameters and pituitary hormones. Food intake was reduced by leptin, but did not change in controls. Leptin treatment elevated plasma lactate and nonesterified fatty acids, but did not affect glucose or insulin levels, indicating a state of negative energy balance that was met by the mobilization of body stores. Pulse analysis showed that the secretion of LH and GH was not affected by leptin treatment, nor were the mean plasma concentrations of FSH, PRL, or cortisol. Expression of messenger RNA for neuropeptide Y in the arcuate nucleus was reduced by the infusion of leptin, primarily due to reduced expression per cell rather than a reduction in the number of cells observed. Thus, the action of leptin to inhibit food intake is dissociated from neuroendocrine function. These results suggest that the metabolic effects of leptin are mediated via neuronal systems that possess leptin receptors rather than via endocrine effects.
- Publication type
- Journal article
- Research centre
- Swinburne University of Technology
- Endocrinology, Vol. 140, no. 3 (Mar 1999), pp. 1175-1182
- Publication year
- FOR Code(s)
- 06 Biological Sciences; 07 Agricultural and Veterinary Sciences; 11 Medical and Health Sciences
- Food intake; Hypophysis; Leptin; Obesity; Ovariectomy
- The Endocrine Society
- Publisher URL
- Copyright © 1999 by The Endocrine Society.
- Peer reviewed