Yonsei Med J.  2004 Feb;45(1):123-128. 10.3349/ymj.2004.45.1.123.

Adrenalectomy Abolishes Fasting-induced Down-regulation of NADPH-diaphorase in the Rat Paraventricular Nucleus

• Jahng JW
• Lee JH
• Kim GT
• Kim YM
• Houpt TA
• Kim DG

• KMID: 1734102
• DOI: http://doi.org/10.3349/ymj.2004.45.1.123

Abstract

This study was conducted to define the molecular mechanism of fasting-induced down-regulation of neuronal nitric oxide synthase (nNOS) expression in the hypothalamic paraventricular nucleus (PVN). Rats were adrenalectomized (ADX), and then either underwent food deprivation or received varying doses of dexamethasone for 48 h. The brain tissues were processed for NADPH-diaphorase (NADPH-d) staining, a histochemical marker of nNOS enzyme activity. Both the ADX and the sham operated rats showed a significant weight loss after 48 h of food deprivation. Food deprivation decreased the number of NADPH-d containing cells in the PVN of sham rats, however, not in the ADX rats. Dexamethasone dose- dependently decreased NADPH-d cells in the PVN of ADX rats. The effect of ADX or dexamethasone was limited to the parvocellular subdivision of PVN. These results suggest that the adrenal glucocorticoids may down-regulate nNOS expression in the PVN during food deprivation.

Keyword

Hypothalamus; neuronal nitric oxide synthase; glucocorticoid

MeSH Terms

*Adrenalectomy
Animals
Biological Markers
Dexamethasone/blood/pharmacology
Down-Regulation/physiology
Fasting/*physiology
Food Deprivation/physiology
Glucocorticoids/blood/pharmacology
Male
NADPH Dehydrogenase/*metabolism
Nitric-Oxide Synthase/*metabolism
Paraventricular Hypothalamic Nucleus/*enzymology
Rats
Rats, Sprague-Dawley
Support, Non-U.S. Gov't