Cold-induced thermogenesis requires GABA in the preoptic area of the hypothalamus
| Project/Area Number |
15590218
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Environmental physiology (including Physical medicine and Nutritional physiology)
|
|---|
| Research Institution | National Institute of Health and Nutrition |
|---|
Principal Investigator |
OSAKA Toshimasa National Institute of Health and Nutrition, Senior Research Scientist, 栄養所要量研究部, 主任研究員 (30152101)
|
|---|
| Project Period (FY) |
2003 – 2005
|
| Project Status |
Completed (Fiscal Year 2005)
|
| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2005: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2004: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000)
|
|---|
| Keywords | cold-induced thermogenesis / rat / autonomic nervous system / oxygen consumption / GABA / preoptic area / adrenal medulla / beta adrenoceptor / 脳 / 下位脳幹 |
|---|
| Research Abstract |
Bilateral microinjections of GABA (300 mM, 100 nl) or the GABA_A receptor agonist muscimol (100 μM, 100 nl) into the preoptic area (POA) of the hypothalamus increased both the rate of whole-body oxygen consumption (VO2) and the body core (colonic) temperature of urethane-chloralose-anesthetized, artificially ventilated rats. The GABA-induced thermogenesis was accompanied by a tachycardic response and electromyographic (EMG) activity recorded from the femoral or neck muscles. Pretreatment with muscle relaxants (1 mg/kg pancuronium bromide plus 4 mg/kg vecuronium bromide, I.V.) prevented the GABA-induced EMG activity but had no significant effect on the GABA-induced thermogenesis. However, pretreatment with the β-adrenoceptor propranolol (5 mg/kg, I.V.) greatly attenuated the GABA-induced increase in VO2 and tachycardic responses. Accordingly, the GABA-induced increase in VO2 reflected mainly nonshivering thermogenesis. On the other hand, cooling of the shaved back of the rat by contact with a plastic bag containing 28 ℃ water also elicited thermogenic, tachycardic, and EMG responses. Bilateral microinjections of the GABA_A receptor antagonist bicuculline (500 μM, 100 nl), but not those of vehicle saline, into the POA blocked these skin cooling-induced responses. These results suggest that cold-induced thermogenesis requires GABA and GABA_A receptors in the POA.
|
Report
(4 results)
Research Products
(12 results)
