Abstract
1 Strips of guinea-pig gall bladder readily accumulate 3H following incubation in the presence of 5 × 10-8 M (-)-[3H]-noradrenaline. This accumulation was reduced by lowering the incubation temperature (from 37° to 23°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 3H.
2 Following preloading of strips of guinea-pig gall bladder with 3.6 × 10-7 M (-)-[3H]-noradrenaline for 1 h, the spontaneous overflow of 3H 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 3H. KCl (10-1 M), (-)-noradrenaline (10-5 M), (-)-adrenaline (10-5 M), and tyramine (10-5 M) increased the overflow of 3H. These results illustrate similar characteristics of the guinea-pig gall bladder to other noradrenergically-innervated tissues in accumulating and releasing 3H following incubation in the presence of [3H]-noradrenaline.
3 Following incubation in the presence of 3.6 × 10-7 M (-)-[3H]-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 3H 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 3H 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 3H is due to the stimulation of noradrenergic nerves.
4 The overflow of 3H evoked by field stimulation at 5 Hz was unaltered and increased by propranolol (10-6 M) and phentolamine (10-6 M), respectively. Clonidine (5 × 10-5 M) had no effect in the absence but reduced the amount of 3H 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 × 10-6, 10-5 and 5 × 10-5 M) whether or not atropine (10-6 M) was present. These results illustrate the presence of postsynaptic α-adrenoceptors and suggest the presence of presynaptic α-adrenoceptors in the gall bladder of the guinea-pig.
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Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Baumgarten H. G., Lange W. Extrinsic adrenergic innervation of the extrahepatic biliary duct system in guinea-pigs, cats and rhesus monkeys. Z Zellforsch Mikrosk Anat. 1969 Sep 22;100(4):606–615. doi: 10.1007/BF00344379. [DOI] [PubMed] [Google Scholar]
- Davison J. S., Al-Hassani M., Crowe R., Burnstock G. The non-adrenergic, inhibitory innervation of the guinea-pig gallbladder. Pflugers Arch. 1978 Oct 18;377(1):43–49. doi: 10.1007/BF00584372. [DOI] [PubMed] [Google Scholar]
- Davison J. S., Fösel S. Interactions between vagus nerve stimulation and pentagastrin or secretin on the guinea pig gallbladder. Digestion. 1975;13(4):251–254. doi: 10.1159/000197715. [DOI] [PubMed] [Google Scholar]
- Doggrell S. A., Woodruff G. N. Effect of 6-hydroxydopamine incubation on noradrenaline accumulation and on contractile responses in the rat anococcygeus muscle. Res Commun Chem Pathol Pharmacol. 1978 May;20(2):253–264. [PubMed] [Google Scholar]
- Doggrell S. A., Woodruff G. N. Effects of antidepressant drugs on noradrenaline accumulation and contractile responses in the rat anococcygeus muscle. Br J Pharmacol. 1977 Mar;59(3):403–409. doi: 10.1111/j.1476-5381.1977.tb08393.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Medgett I. C., McCulloch M. W., Rand M. J. Partial agonist of clonidine on prejunctional and postjunctional alpha-adrenoceptors. Naunyn Schmiedebergs Arch Pharmacol. 1978 Oct;304(3):215–221. doi: 10.1007/BF00507961. [DOI] [PubMed] [Google Scholar]
- Prichard B. N. The second Lilly Prize Lecture, University of Newcastle, July 1977. beta-Adrenergic receptor blockade in hypertension, past, present and future. Br J Clin Pharmacol. 1978 May;5(5):379–399. doi: 10.1111/j.1365-2125.1978.tb01644.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Starke K., Montel H., Gayk W., Merker R. Comparison of the effects of clonidine on pre- and postsynaptic adrenoceptors in the rabbit pulmonary artery. Alpha-sympathomimetic inhibition of Neurogenic vasoconstriction. Naunyn Schmiedebergs Arch Pharmacol. 1974;285(2):133–150. doi: 10.1007/BF00501149. [DOI] [PubMed] [Google Scholar]
- Starke K. Regulation of noradrenaline release by presynaptic receptor systems. Rev Physiol Biochem Pharmacol. 1977;77:1–124. doi: 10.1007/BFb0050157. [DOI] [PubMed] [Google Scholar]
