Orexin-A immunoreactivity and prepro-orexin mRNA expression in hyperphagic rats induced by hypothalamic lesions and lactation

被引:15
作者
Sun, G [1 ]
Narita, K [1 ]
Murata, T [1 ]
Honda, K [1 ]
Higuchi, T [1 ]
机构
[1] Fukui Med Univ, Dept Physiol, Fukui 9101193, Japan
关键词
orexin-A; prepro-orexin mRNA; ventromedial hypothalamus; paraventricular nucleus; lactation; immunohistochemistry; lateral hypothalamus;
D O I
10.1046/j.1365-2826.2003.00862.x
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
Orexins are endogenous neuropeptides that potently facilitate appetite and food consumption. In the present study, we examined orexin immunoreactivity and prepro-orexin mRNA expression in the lateral hypothalamus by immunohistochemistry and competitive reverse transcription-polymerase chain reaction (RT-PCR) methods in different models of hyperphagia in rats. Hyperphagia was induced by lesions of either the ventromedial hypothalamus (VMHL) or the paraventricular nucleus (PVNL), and we also compared lactating rats to nonlactating controls. Both VMHL and PVNL increased food intake and body weight compared to shams. On day 7 post lesion, serum leptin and insulin concentrations exhibited 3.2- and 2.8-fold increases in VMHL rats, and nonsignificant 1.8- and 1.8-fold increases in PVNL rats; there were significant decreases (48% and 33%) in lactating rats on day 12 postpartum compared to controls, respectively. Serum glucose concentrations were not significantly changed compared to controls in these rats. Quantification by image analysis suggests that VMHL significantly decreased the number and mean staining intensity of orexin-A immunoreactive neurones compared to those in the sham-lesioned group; while PVNL did not change orexin-A immunoreactivity. Competitive RT-PCR analysis showed that VMHL significantly decreased the prepro-orexin mRNA expression compared to those in the sham-lesioned group, and PVNL did not change it. Lactating rats on days 11-12 of lactation had significantly greater number and mean staining intensity of orexin-A immunoreactive neurones, prepro-orexin mRNA expression food intake and body weight than nonlactating postpartum rats. Thus, changes in orexin-A immunoreactivity and prepro-orexin mRNA expression were not consistent between the hyperphagia models. These results suggest that the hyperphagia from VMHL or PVNL and lactating rats differ in their involvement of orexin-A, and the change in circulating leptin and insulin concentrations may be involved in the change of orexin-A immunoreactivity in these rats.
引用
收藏
页码:51 / 60
页数:10
相关论文
共 49 条
  • [1] [Anonymous], 1979, A Stereotaxic Atlas of the Rat Brain
  • [2] Obesity-inducing lesions of the central nervous system alter leptin uptake by the blood-brain barrier
    Banks, WA
    King, BM
    Rossiter, KN
    Olson, RD
    Olson, GA
    Kastin, AJ
    [J]. LIFE SCIENCES, 2001, 69 (23) : 2765 - 2773
  • [3] Hypothalamic hypocretin/orexin and neuropeptide Y: Divergent interaction with energy depletion and leptin
    Beck, B
    Richy, S
    [J]. BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 1999, 258 (01) : 119 - 122
  • [4] The lateral hypothalamic area revisited: Ingestive behavior
    Bernardis, LL
    Bellinger, LL
    [J]. NEUROSCIENCE AND BIOBEHAVIORAL REVIEWS, 1996, 20 (02) : 189 - 287
  • [5] Broberger C, 1998, J COMP NEUROL, V402, P460
  • [6] Differential regulation of leptin receptor but not orexin in the hypothalamus of the lactating rat
    Brogan, RS
    Grove, KL
    Smith, MS
    [J]. JOURNAL OF NEUROENDOCRINOLOGY, 2000, 12 (11) : 1077 - 1086
  • [7] INCREASED INSULIN SENSITIVITY AND RESPONSIVENESS DURING LACTATION IN RATS
    BURNOL, AF
    LETURQUE, A
    FERRE, P
    KANDE, J
    GIRARD, J
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY, 1986, 251 (05): : E537 - E541
  • [8] Hypothalamic orexin expression - Modulation by blood glucose and feeding
    Cai, XJ
    Widdowson, PS
    Harrold, J
    Wilson, S
    Buckingham, RE
    Arch, JRS
    Tadayyon, M
    Clapham, JC
    Wilding, J
    Williams, G
    [J]. DIABETES, 1999, 48 (11) : 2132 - 2137
  • [9] Food restriction selectively increases hypothalamic orexin-B levels in lactating rats
    Cai, XJ
    Denis, R
    Vernon, RG
    Clapham, JC
    Wilson, S
    Arch, JRS
    Williams, G
    [J]. REGULATORY PEPTIDES, 2001, 97 (2-3) : 163 - 168
  • [10] Rats with hypothalamic obesity are insensitive to central leptin injections
    Choi, SJ
    Sparks, R
    Clay, M
    Dallman, MF
    [J]. ENDOCRINOLOGY, 1999, 140 (10) : 4426 - 4433