Abstract
Supramaximal stimulation of the periarterial nerves in the mesentery to the rabbit isolated ileum causes inhibition which is increased when hyoscine is added to the bath. This increase is, however, usually seen only when the stimulus frequency is low, and the addition of hyoscine usually makes no difference when the frequency is 10 shocks/sec or more. The observations suggest that, at low frequency, stimulation releases both acetylcholine and noradrenaline, but that at higher frequencies only noradrenaline is released. Similar observations have been made for the nictitating membrane of the cat. When the postganglionic fibres from the superior cervical ganglion were stimulated supramaximally, the contractions of the membrane increased in size as the frequency rose. In the presence of hyoscine the contractions were smaller, the greatest difference being for the lowest stimulus frequency, the difference diminishing as the frequency rose. These observations are consistent with the view that sympathetic cholinergic fibres in many situations release acetylcholine to act directly only at low frequencies, and that at higher frequencies the acetylcholine is almost entirely used to release noradrenaline.
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Selected References
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- BURN J. H., RAND M. J. The relation of circulating noradrenaline to the effect of sympathetic stimulation. J Physiol. 1960 Feb;150:295–305. doi: 10.1113/jphysiol.1960.sp006388. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BURN J. H., RAND M. J., WIEN R. The adrenergic mechanism in the nictitating membrane. Br J Pharmacol Chemother. 1963 Feb;20:83–94. doi: 10.1111/j.1476-5381.1963.tb01299.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BURN J. H., WEETMAN D. F. The effect of eserine on the response of the vas deferens to hypogastric nerve stimulation. Br J Pharmacol Chemother. 1963 Feb;20:74–82. doi: 10.1111/j.1476-5381.1963.tb01298.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DAY M. D., RAND M. J. Effect of guanethidine in revealing cholinergic sympathetic fibres. Br J Pharmacol Chemother. 1961 Oct;17:245–260. doi: 10.1111/j.1476-5381.1961.tb01285.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- EMMELIN N., ENGSTROM J. On the existence of specific secretory sympathetic fibres for the cat's submaxillary gland. J Physiol. 1960 Aug;153:1–8. doi: 10.1113/jphysiol.1960.sp006514. [DOI] [PMC free article] [PubMed] [Google Scholar]
- GILLESPIE J. S., MACKENNA B. R. The inhibitory action of the sympathetic nerves on the smooth muscle of the rabbit gut, its reversal by reserpine and restoration by catechol amines and by DOPA. J Physiol. 1961 Apr;156:17–34. doi: 10.1113/jphysiol.1961.sp006655. [DOI] [PMC free article] [PubMed] [Google Scholar]
- OHLIN P., STROMBLAD B. C. Observations on the isolated vas deferens. Br J Pharmacol Chemother. 1963 Apr;20:299–306. doi: 10.1111/j.1476-5381.1963.tb01469.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SJOSTRAND N. O. Inhibition by ganglionic blocking agents of the motor response of the isolated guinea-pig vas deferens to hypogastric nerve stimulation. Acta Physiol Scand. 1962 Mar-Apr;54:306–315. doi: 10.1111/j.1748-1716.1962.tb02354.x. [DOI] [PubMed] [Google Scholar]
- VOGT M. Hypogastric nerve of the dog. Nature. 1963 Feb 23;197:804–805. doi: 10.1038/197804a0. [DOI] [PubMed] [Google Scholar]