Nakamori T, Morimoto A, Morimoto K, Tan N, Murakami N
Department of Physiology, Yamaguchi University School of Medicine, Japan.
Am J Physiol. 1993 Jan;264(1 Pt 2):R156-61. doi: 10.1152/ajpregu.1993.264.1.R156.
We investigated the effects of intraperitoneal injection of alpha- and beta-adrenergic antagonists on psychological stress-induced responses in free-moving rats. Psychological stress was induced by immersion in 2-cm-deep water. The intraperitoneal injection of the alpha-adrenergic blocker, phentolamine (10 mg/kg), attenuated the stress-induced rise in body temperature and hypertension but enhanced tachycardia. In contrast, intraperitoneal injection of the beta-adrenergic blocker, propranolol (1 mg/kg), suppressed tachycardia but had no effect on rise in body temperature and hypertension during stress. The intraperitoneal injection of both blockers had no effect on the increase in metabolic rate (O2 consumption) induced by stress. The intravenous injection of propranolol (1 mg/kg) suppressed the stress-induced rise in body temperature. We then examined the effect of intracerebroventricular injection of propranolol on the stress-induced rise in body temperature and found that intracerebroventricular injection of propranolol (50 micrograms) suppressed the stress-induced rise in body temperature. These results support the following hypotheses: 1) Systemic injection of phentolamine suppresses the psychological stress-induced rise in body temperature by facilitating heat-loss; 2) Peripheral beta-adrenergic stimulation probably does not contribute to psychological stress-induced rises in body temperature; and 3) central beta-adrenergic receptors are important in stress-induced increases in body temperature.
我们研究了腹腔注射α-和β-肾上腺素能拮抗剂对自由活动大鼠心理应激诱导反应的影响。通过将大鼠浸入2厘米深的水中诱导心理应激。腹腔注射α-肾上腺素能阻滞剂酚妥拉明（10毫克/千克）可减弱应激诱导的体温升高和高血压，但会增强心动过速。相比之下，腹腔注射β-肾上腺素能阻滞剂普萘洛尔（1毫克/千克）可抑制心动过速，但对应激期间的体温升高和高血压没有影响。腹腔注射两种阻滞剂对应激诱导的代谢率（耗氧量）增加没有影响。静脉注射普萘洛尔（1毫克/千克）可抑制应激诱导的体温升高。然后我们研究了脑室内注射普萘洛尔对应激诱导的体温升高的影响，发现脑室内注射普萘洛尔（50微克）可抑制应激诱导的体温升高。这些结果支持以下假设：1）全身注射酚妥拉明通过促进散热来抑制心理应激诱导的体温升高；2）外周β-肾上腺素能刺激可能对心理应激诱导的体温升高没有作用；3）中枢β-肾上腺素能受体在应激诱导的体温升高过程中很重要。
