AJP - Regulatory, Integrative and Comparative Physiology, Vol 268, Issue 2 389-R394, Copyright © 1995 by American Physiological Society

ARTICLES

Reduced norepinephrine turnover in organs and brains of obesity-prone rats

B. E. Levin
Department of Veterans Affairs Medical Center, East Orange, New Jersey 07018.

One-half of the adult male Sprague-Dawley rats fed a diet relatively high in fat, sucrose, and energy content (HE diet) develop diet-induced obesity (DIO). The rest are diet resistant (DR). The role of peripheral and central norepinephrine (NE) activity in predisposing them to these weight gain patterns was assessed before HE diet exposure. Chow-fed male 3-mo-old Sprague-Dawley rats were separated as being prone to become DIO or DR by their high (3.06 +/- 0.14 micrograms) vs. low (1.17 +/- 0.10 micrograms; P = 0.001) 24-h urine NE output, respectively. Turnover of NE, an index of sympathetic activity, was assessed by synthesis inhibition with alpha-methyl-p-tyrosine. DIO-prone rats had significant 53 and 18% reductions in heart and pancreas NE turnover, with interscapular brown adipose tissue turnover comparable to that of DR-prone rats. Hypothalamic NE turnover was significantly decreased by 85 and 60% in the ventromedial nucleus and lateral area vs. DR-prone rats. Although present in DR-prone rats, no turnover was found in the dorsomedial nucleus of DIO-prone rats. Endogenous NE was reduced by 28% in the paraventricular nucleus, whereas arcuate/median eminence turnover was increased by 100% in DIO-prone rats. Amygdalar NE turnover was similar between phenotypes. These intrinsic differences in NE metabolism may play an important role in the development of DIO on HE diets.

This article has been cited by other articles:

				J. A. Teske, A. S. Levine, M. Kuskowski, J. A. Levine, and C. M. Kotz Elevated hypothalamic orexin signaling, sensitivity to orexin A, and spontaneous physical activity in obesity-resistant rats Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2006; 291(4): R889 - R899. [Abstract] [Full Text] [PDF]

				D. J. Clegg, S. C. Benoit, J. A. Reed, S. C. Woods, A. Dunn-Meynell, and B. E. Levin Reduced anorexic effects of insulin in obesity-prone rats fed a moderate-fat diet Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2005; 288(4): R981 - R986. [Abstract] [Full Text] [PDF]

				C. Cruciani-Guglielmacci, M. Vincent-Lamon, C. Rouch, M. Orosco, A. Ktorza, and C. Magnan Early changes in insulin secretion and action induced by high-fat diet are related to a decreased sympathetic tone Am J Physiol Endocrinol Metab, January 1, 2005; 288(1): E148 - E154. [Abstract] [Full Text] [PDF]

				B. E. Levin The drive to regain is mainly in the brain Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2004; 287(6): R1297 - R1300. [Full Text] [PDF]

				M. A. Christoffolete, C. C.G. Linardi, L. de Jesus, K. N. Ebina, S. D. Carvalho, M. O. Ribeiro, R. Rabelo, C. Curcio, L. Martins, E. T. Kimura, et al. Mice with Targeted Disruption of the Dio2 Gene Have Cold-Induced Overexpression of the Uncoupling Protein 1 Gene but Fail to Increase Brown Adipose Tissue Lipogenesis and Adaptive Thermogenesis Diabetes, March 1, 2004; 53(3): 577 - 584. [Abstract] [Full Text] [PDF]

				B. E. Levin, A. A. Dunn-Meynell, and W. A. Banks Obesity-prone rats have normal blood-brain barrier transport but defective central leptin signaling before obesity onset Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2004; 286(1): R143 - R150. [Abstract] [Full Text]

				C. Michel, B. E. Levin, and A. A. Dunn-Meynell Stress facilitates body weight gain in genetically predisposed rats on medium-fat diet Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2003; 285(4): R791 - R799. [Abstract] [Full Text] [PDF]

				R. Burcelin, V. Crivelli, A. Dacosta, A. Roy-Tirelli, and B. Thorens Heterogeneous metabolic adaptation of C57BL/6J mice to high-fat diet Am J Physiol Endocrinol Metab, April 1, 2002; 282(4): E834 - E842. [Abstract] [Full Text] [PDF]

				B. E. Levin and A. A. Dunn-Meynell Defense of body weight depends on dietary composition and palatability in rats with diet-induced obesity Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2002; 282(1): R46 - R54. [Abstract] [Full Text] [PDF]

				B. E. Levin, D. Richard, C. Michel, and R. Servatius Differential stress responsivity in diet-induced obese and resistant rats Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2000; 279(4): R1357 - R1364. [Abstract] [Full Text] [PDF]

				B. E. Levin Arcuate NPY neurons and energy homeostasis in diet-induced obese and resistant rats Am J Physiol Regulatory Integrative Comp Physiol, February 1, 1999; 276(2): R382 - R387. [Abstract] [Full Text] [PDF]

				M. Vaz, G. Jennings, A. Turner, H. Cox, G. Lambert, and M. Esler Regional Sympathetic Nervous Activity and Oxygen Consumption in Obese Normotensive Human Subjects Circulation, November 18, 1997; 96(10): 3423 - 3429. [Abstract] [Full Text]