Russek M, Vega C, Barrera J, Soto-Mora L M, Lanzagorta A, Racotta R
National School of Biological Sciences, IPN, Mexico City.
Appetite. 1987 Oct;9(2):119-26. doi: 10.1016/0195-6663(87)90041-9.
Adrenaline (A) produces a strong anorexic effect, possibly by acting on hepatic receptors (nerve endings on hepatocytes). To study whether this is mediated by alpha- or beta-adrenergic mechanisms, or both, the anorexigenic effects of intraperitoneal injections of A, noradrenaline (NA) and isoproterenol (I) were studied under four different experimental conditions: (I) at the beginning of the dark period in rats fed ad libitum, or (II) on a 24 h-feeding/24 h-fasting schedule; (III) during the light period, under the same feeding schedule; (IV) after an acute 24 h fast. In condition I, the three catecholamines produced a marked decrease in feeding, slightly larger for A. In condition II (dark), they elicited a decrease in food intake about double that in condition III (light), their relative potencies also differed: A greater than I greater than NA in II and A greater than I = NA in III. In IV, the same relative potencies were obtained as in III. A mixture of half-doses of NA and I had the same effect in III and IV as either NA or I alone, suggesting that the alpha and beta effects are additive. However, even a mixture of the full doses of NA and I was not as effective as A in condition IV. This suggests that A is more potent than NA or I at stimulating hepatic adrenergic receptors that cannot be classified as either alpha or beta.
肾上腺素（A）可能通过作用于肝脏受体（肝细胞上的神经末梢）产生强烈的厌食作用。为了研究这是否由α-或β-肾上腺素能机制介导，或者两者都介导，在四种不同的实验条件下研究了腹腔注射A、去甲肾上腺素（NA）和异丙肾上腺素（I）的厌食作用：（I）在随意进食的大鼠的黑暗期开始时，或（II）按照24小时进食/24小时禁食的时间表；（III）在相同的进食时间表下的光照期；（IV）在急性禁食24小时后。在条件I下，三种儿茶酚胺均使进食量显著减少，A的减少量略大。在条件II（黑暗）下，它们引起的食物摄入量减少约为条件III（光照）下的两倍，它们的相对效力也有所不同：在II中A＞I＞NA，在III中A＞I = NA。在IV中，获得了与III相同的相对效力。NA和I半剂量的混合物在III和IV中的效果与单独使用NA或I相同，这表明α和β效应是相加的。然而，即使是NA和I全剂量的混合物在条件IV下也不如A有效。这表明在刺激无法归类为α或β的肝脏肾上腺素能受体方面，A比NA或I更有效。
