Harper B, Hughes I E, Noormohamed F H
J Pharm Pharmacol. 1978 Mar;30(3):167-72. doi: 10.1111/j.2042-7158.1978.tb13190.x.
In isolated tissues from reserpinized rabbits (5 mg kg-1, i.m. 20 h before experiment) and in the presence of cocaine (3 x 10(-5) M), corticosterone (2.8 x 10(-5)M), tropolone (3 x 10(-5) M), propranolol (4 x 10(-5)M) and disodium EDTA (3 X 10(-5)M), the potency ratios (relative to (-)-noradrenaline) of (-)adrenaline, (-)-phenylephrine and (+/-)-methoxamine were (m+/-s.e.) 2.03 +/- 0.13, 0.045 +/- 0.003 and 0.0062 +/- 0.0018 respectively in splenic strips and 1.77 +/- 0.41, 0.093 +/- 0.018 and 0.029 +/- 0.004 respectively in isolated ileum. Although the pA2 values for phentolamine and thymoxamine against (-)-noradrenaline in the two tissues were very similar there was a statistically significant difference when using yohimbine as the alpha-adrenoceptor blocking agent (pA2 = 6.80 +/- 0.30 in spleen; 5.60 +/- 0.12 in ileum). These differences suggest that the alpha-adrenoceptor in the two tissues is not identical. The pA2 value of phentolamine in rabbits ileum was not significantly different whether (-)noradrenaline or (+/-) methoxamine was used as agonist (7.91 +/- 0.07 and 7.97 +/- 0.06 respectively) while that of yohimbine was 5.56 +/- 0.10 using (-)noradrenaline and 6.19 +/- 0.12 using (+/-)methoxamine. In the light of this latter result and, considering the scatter of the experimentally determined values, there may be two alpha-adrenoceptors in rabbit ileum and either or both may not be identical in all respects to the alpha-adrenoceptor found in rabbit spleen.
在利血平化家兔（实验前20小时腹腔注射5mg/kg）的离体组织中，在可卡因（3×10⁻⁵M）、皮质酮（2.8×10⁻⁵M）、托酚酮（3×10⁻⁵M）、普萘洛尔（4×10⁻⁵M）和乙二胺四乙酸二钠（3×10⁻⁵M）存在的情况下，脾条中（-）肾上腺素、（-）去氧肾上腺素和（±）甲氧明的效价比（相对于（-）去甲肾上腺素，均值±标准误）分别为2.03±0.13、0.045±0.003和0.0062±0.0018，离体回肠中分别为1.77±0.41、0.093±0.018和0.029±0.004。尽管酚妥拉明和噻吗洛尔对两种组织中（-）去甲肾上腺素的pA₂值非常相似，但使用育亨宾作为α-肾上腺素能受体阻断剂时存在统计学显著差异（脾中pA₂ = 6.80±0.30；回肠中5.60±0.12）。这些差异表明两种组织中的α-肾上腺素能受体并不相同。在家兔回肠中，无论使用（-）去甲肾上腺素还是（±）甲氧明作为激动剂，酚妥拉明的pA₂值均无显著差异（分别为7.91±0.07和7.97±0.06），而育亨宾使用（-）去甲肾上腺素时pA₂为5.56±0.10，使用（±）甲氧明时为6.19±0.12。鉴于后一结果，并考虑到实验测定值的离散性，家兔回肠中可能存在两种α-肾上腺素能受体，其中任何一种或两种在所有方面可能与家兔脾脏中发现的α-肾上腺素能受体并不相同。
