Departamento de Ciências Fisiológicas, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
Braz J Med Biol Res. 2011 Nov;44(11):1141-7. doi: 10.1590/s0100-879x2011007500127. Epub 2011 Sep 30.
This study examined the food intake changes evoked by intracerebroventricular (icv) injection of a selective agonist (BRL37344, 2 and 20 nmol) or antagonist (SR59230A, 10 and 50 nmol) of β3-adrenergic receptors in 24-h fasted rats (adult male Wistar rats, 200-350 g, N = 6/treatment). The animals were also pretreated with saline icv (SAL) or SR59230A (50 nmol) followed by BRL37344 (20 nmol) or SAL in order to determine the selectivity of the effects evoked by BRL37344 on food intake or the selectivity of the effects evoked by SR59230A on risk assessment (RA) behavior. The highest dose of BRL37344 (N = 7) decreased food intake 1 h after the treatment (6.4 ± 0.5 g in SAL-treated vs 4.2 ± 0.8 g in drug-treated rats). While both doses of SR59230A failed to affect food intake (5.1 ± 1.1 g for 10 nmol and 6.0 ± 1.8 g for 50 nmol), this treatment reduced the RA frequency (number/30 min) (4 ± 2 for SAL-treated vs 1 ± 1 for 10 nmol and 0.5 ± 1 for 50 nmol SR59230A-treated rats), an ethological parameter related to anxiety. While pretreatment with SR59230A (7.0 ± 0.5 g) abolished the hypophagia induced by BRL37344 (3.6 ± 0.9 g), BRL37344 suppressed the reduction in RA frequency caused by SR59230A. These results show that the hypophagia caused by BRL37344 is selectively mediated by β3-adrenergic receptors within the central nervous system. Moreover, they suggest the involvement of these receptors in the control of anxiety.
这项研究检查了在 24 小时禁食的大鼠（成年雄性 Wistar 大鼠，200-350g，N=6/处理）中，脑室内（icv）注射选择性激动剂（BRL37344，2 和 20nmol）或拮抗剂（SR59230A，10 和 50nmol）β3-肾上腺素能受体后引起的食物摄入变化。动物还预先用盐水 icv（SAL）或 SR59230A（50nmol）预处理，然后用 BRL37344（20nmol）或 SAL 处理，以确定 BRL37344 对食物摄入的影响的选择性，或 SR59230A 对风险评估（RA）行为的影响的选择性。最高剂量的 BRL37344（N=7）在治疗后 1 小时降低了食物摄入量（SAL 处理组为 6.4±0.5g，药物处理组为 4.2±0.8g）。虽然两种剂量的 SR59230A 都没有影响食物摄入（10nmol 时为 5.1±1.1g，50nmol 时为 6.0±1.8g），但这种处理降低了 RA 频率（次数/30min）（SAL 处理组为 4±2，10nmol 处理组为 1±1，50nmol SR59230A 处理组为 0.5±1），这是一种与焦虑相关的行为学参数。虽然用 SR59230A 预处理（7.0±0.5g）消除了 BRL37344 引起的食欲减退（3.6±0.9g），但 BRL37344 抑制了 SR59230A 引起的 RA 频率降低。这些结果表明，BRL37344 引起的食欲减退是由中枢神经系统内的β3-肾上腺素能受体选择性介导的。此外，它们表明这些受体参与了焦虑的控制。
