These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Effects of adenosine 5'-monophosphate and adenosine 5'-triphosphate on functionally identified units in the cat spinal dorsal horn. Evidence for a differential effect of adenosine 5'-triphosphate on nociceptive vs non-nociceptive units.
    Author: Salter MW, Henry JL.
    Journal: Neuroscience; 1985 Jul; 15(3):815-25. PubMed ID: 2999643.
    Abstract:
    A study was done of the effects of iontophoretic application of adenosine 5'-monophosphate (AMP) and adenosine 5'-triphosphate (ATP) on functionally identified neurones in the spinal dorsal horn of the cat. AMP depressed nearly two-thirds of the 32 neurones tested regardless of functional type; the remainder were unaffected. ATP, on the other hand, had three types of effect: depression, excitation and a biphasic effect which consisted of excitation followed by depression. A significant difference was found when a comparison was made of the frequency of occurrence of each of these three types of effect in the samples of non-nociceptive (n = 18) and of wide dynamic range neurones (n = 42): of non-nociceptive neurones 61% were excited, 11% were depressed, 6% had a biphasic response and 22% were unaffected; of wide dynamic range neurones 45% had a biphasic response, 19% were depressed, 14% were excited and 21% were unaffected (chi 2 = 16.2, P less than 0.005). The depressant effects of both AMP and ATP and the depressant phase of the biphasic effect of ATP seem to be mediated through activation of P1-purinergic receptors because these effects were blocked by theophylline, a P1-purinergic antagonist [Burnstock (1978) In Cell Membrane Receptors for Drugs and Hormones: A Multidisciplinary Approach, pp. 107-118]. Thus the biphasic effect appears to consist of excitatory and depressant responses in the same neurone. The differential effects of ATP on non-nociceptive vs wide dynamic-range neurones are similar to the differential effects on these neurones observed during activation of low-threshold primary afferents. This similarity, together with evidence that ATP can be released from primary afferent neurones [Holton and Holton (1954) J. Physiol., Lond. 126, 124-140; Holton (1959) J. Physiol., Lond. 145, 494-504], prompts us to suggest that ATP may be a chemical mediator of effects of low-threshold primary afferent inputs in the spinal dorsal horn.
    [Abstract] [Full Text] [Related] [New Search]