Failure of presynaptic purinoceptors to modulate noradrenaline release from sympathetic nerves in human dental pulp.
The effects of putative presynaptic P1- and/or P2-purinoceptors on the release of noradrenaline from sympathetic nerves in human dental pulp were examined by testing the effects of agonists and an antagonist of these receptors on the stimulation-induced overflow of [(3)H]noradrenaline from tissue treated with desipramine (0.3 micromol/l) and preincubated with [(3)H]noradrenaline (0.6 micromol/l). The P1-purinoceptor agonists adenosine (1.0 mmol/l) and 2-chloroadenosine (0.01-1.0 mmol/l) and the antagonist 8-cyclopentyl-1,3-dipropyl xanthine (1.0 micromol/l), and the P2-purinoceptor agonists ATP (0.1 mmol/l) and beta, gamma-methylene-ATP (0.01 mmol/l), did not modulate the release of noradrenaline. Adenosine was also without effect in dental pulp treated with the alpha(2)-adrenoceptor antagonist rauwolscine. It is concluded that presynaptic P1-purinoceptors and those P2-purinoceptors activated by adenine nucleotides are either not present on sympathetic nerves in human dental pulp or that they exert little or no effect on the release of noradrenaline.
Parker
D A
DA
Dental School, The University of Adelaide, South Australia 5005, Adelaide, Australia. david.parker@adelaide.edu.au
Marino
V
V
Krishna
M
M
Narayanan
A
A
de la Lande
I S
IS
D015762:2-Chloroadenosine / Q000494:pharmacology; D000227:Adenine Nucleotides / Q000494:pharmacology; D000241:Adenosine / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D046508:Culture Techniques; D003782:Dental Pulp / Q000294:innervation*; D003891:Desipramine / Q000494:pharmacology; D006801:Humans; D009638:Norepinephrine / Q000378:metabolism*; D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D019275:Radiopharmaceuticals; D017661:Receptors, Presynaptic / Q000819:agonists / Q000037:antagonists & inhibitors / Q000502:physiology*; D018047:Receptors, Purinergic P1 / Q000502:physiology*; D018048:Receptors, Purinergic P2 / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000378:metabolism*; D013566:Sympathomimetics / Q000378:metabolism*; D014316:Tritium; D014970:Xanthines / Q000494:pharmacology; D015016:Yohimbine / Q000494:pharmacology
D000227:Adenine Nucleotides; D018759:Adrenergic Uptake Inhibitors; D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D019275:Radiopharmaceuticals; D017661:Receptors, Presynaptic; D018047:Receptors, Purinergic P1; D018048:Receptors, Purinergic P2; D013566:Sympathomimetics; D014970:Xanthines; D014316:Tritium; D015762:2-Chloroadenosine; D015016:Yohimbine; C005147:5'-adenylyl (beta,gamma-methylene)diphosphonate; D000255:Adenosine Triphosphate; C051360:1,3-dipropyl-8-cyclopentylxanthine; D000241:Adenosine; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D003891:Desipramine; D009638:Norepinephrine