豚鼠胆囊与[³H]-去甲肾上腺素孵育后³H的蓄积与溢出。

Accumulation and overflow of 3H following incubation of the guinea-pig gall bladder with [3H]-noradrenaline.

作者信息

Doggrell S A, Vincent L

出版信息

Br J Pharmacol. 1980;71(2):557-67. doi: 10.1111/j.1476-5381.1980.tb10973.x.

DOI:10.1111/j.1476-5381.1980.tb10973.x

PMID:7470762

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC2044469/

Abstract

1 Strips of guinea-pig gall bladder readily accumulate (3)H following incubation in the presence of 5 x 10(-8) M (-)-[(3)H]-noradrenaline. This accumulation was reduced by lowering the incubation temperature (from 37 degrees to 23 degrees C), by cocaine (10(-6) M), by nortriptyline (10(-8), 10(-6) and 10(-4) M) and following incubation of the tissues with 6-hydroxydopamine (10(-3) M for 3 h). At 10(-6) M, (-)-noradrenaline and (-)-adrenaline, but not (-)-isoprenaline, inhibited the accumulation of (3)H.2 Following preloading of strips of guinea-pig gall bladder with 3.6 x 10(-7) M (-)-[(3)H]-noradrenaline for 1 h, the spontaneous overflow of (3)H was observed. Cocaine (10(-4) M), nortriptyline (10(-6) M), (-)-isoprenaline (10(-5) M), acetylcholine (10(-5) M) and adenosine 5'-triphosphate (ATP, 10(-4) M) had no effect on the spontaneous overflow of (3)H. KCl (10(-1) M), (-)-noradrenaline (10(-5) M), (-)-adrenaline (10(-5) M), and tyramine (10(-5) M) increased the overflow of (3)H. These results illustrate similar characteristics of the guinea-pig gall bladder to other noradrenergically-innervated tissues in accumulating and releasing (3)H following incubation in the presence of [(3)H]-noradrenaline.3 Following incubation in the presence of 3.6 x 10(-7) M (-)-[(3)H]-noradrenaline, field stimulation, at 5 Hz, of strips of gall bladder, in the absence or presence of 10(-6) M atropine, increased the overflow of (3)H and, simultaneously, induced contractions. The contractile responses to 5 Hz were smaller in the presence than in the absence of 10(-4) M lignocaine. Lignocaine (10(-4) M) reduced the overflow of (3)H evoked by field stimulation at 5 Hz. It is suggested that the contractile responses to 5 Hz are due to nerve stimulation and that the increased overflow of (3)H is due to the stimulation of noradrenergic nerves.4 The overflow of (3)H evoked by field stimulation at 5 Hz was unaltered and increased by propranolol (10(-6) M) and phentolamine (10(-6) M), respectively. Clonidine (5 x 10(-5) M) had no effect in the absence but reduced the amount of (3)H which overflowed in response to field stimulation at 5 Hz in the presence of 10(-6) M atropine. The contractile responses to field stimulation at 5 Hz were reduced by phentolamine (10(-6) M) or clonidine (5 x 10(-6), 10(-5) and 5 x 10(-5) M) whether or not atropine (10(-6) M) was present. These results illustrate the presence of postsynaptic alpha-adrenoceptors and suggest the presence of presynaptic alpha-adrenoceptors in the gall bladder of the guinea-pig.

摘要

豚鼠胆囊条在5×10⁻⁸ M（⁻）-[³H]-去甲肾上腺素存在下孵育时，能迅速积累³H。降低孵育温度（从37℃降至23℃）、使用可卡因（10⁻⁶ M）、去甲替林（10⁻⁸、10⁻⁶和10⁻⁴ M）以及用6-羟基多巴胺（10⁻³ M孵育3小时）处理组织后，这种积累会减少。在10⁻⁶ M时，（⁻）-去甲肾上腺素和（⁻）-肾上腺素能抑制³H的积累，但（⁻）-异丙肾上腺素不能。
用3.6×10⁻⁷ M（⁻）-[³H]-去甲肾上腺素预加载豚鼠胆囊条1小时后，观察到³H的自发溢出。可卡因（10⁻⁴ M）、去甲替林（10⁻⁶ M）、（⁻）-异丙肾上腺素（10⁻⁵ M）、乙酰胆碱（10⁻⁵ M）和腺苷5'-三磷酸（ATP，10⁻⁴ M）对³H的自发溢出没有影响。氯化钾（10⁻¹ M）、（⁻）-去甲肾上腺素（10⁻⁵ M）、（⁻）-肾上腺素（10⁻⁵ M）和酪胺（10⁻⁵ M）会增加³H的溢出。这些结果表明，豚鼠胆囊在（³H）-去甲肾上腺素存在下孵育后积累和释放³H的特性与其他去甲肾上腺素能神经支配的组织相似。
在3.6×10⁻⁷ M（⁻）-[³H]-去甲肾上腺素存在下孵育后，在有无10⁻⁶ M阿托品的情况下，以5 Hz的频率对胆囊条进行场刺激，会增加³H的溢出，同时诱发收缩。在有10⁻⁴ M利多卡因存在时，对5 Hz的收缩反应比不存在时小。利多卡因（10⁻⁴ M）减少了5 Hz场刺激诱发的³H溢出。提示对5 Hz的收缩反应是由于神经刺激，而³H溢出增加是由于去甲肾上腺素能神经的刺激。
5 Hz场刺激诱发的³H溢出分别不受普萘洛尔（10⁻⁶ M）影响和被酚妥拉明（10⁻⁶ M）增加。可乐定（5×10⁻⁵ M）在不存在时无影响，但在有10⁻⁶ M阿托品存在时，会减少5 Hz场刺激诱发的³H溢出量。无论是否存在10⁻⁶ M阿托品，酚妥拉明（10⁻⁶ M）或可乐定（5×10⁻⁶、10⁻⁵和5×10⁻⁵ M）都会降低对5 Hz场刺激的收缩反应。这些结果表明豚鼠胆囊中存在突触后α-肾上腺素能受体，并提示存在突触前α-肾上腺素能受体。