Role played by P2X and P2Y receptors in evoking the muscle chemoreflex.
The role played by purinergic 2Y receptors in evoking the muscle chemoreflex is not well defined. To shed light on this issue, we compared the pressor responses with popliteal arterial injection of UTP (1 mg/kg), a selective P2Y agonist, with those to popliteal arterial injection of ATP (1 mg/kg), a P2X and P2Y agonist, and to alpha,beta-methylene ATP (50 mug/kg), a selective P2X1 and P2X3 agonist, in decerebrate unanesthetized cats. We found that injection of ATP and alpha,beta-methylene ATP increased mean arterial pressure by 19 +/- 2 and 15 +/- 4 mmHg, whereas UTP had no affect on arterial pressure. In addition, the pressor responses to injection of ATP and alpha,beta-methylene ATP were abolished by section of the sciatic nerve, demonstrating that they were reflex in origin. We conclude that P2Y receptors on thin fiber muscle afferents play no role in evoking the muscle chemoreflex.
Heart and Vascular Institute H047, Penn State College of Medicine, 500 Univ. Dr., Hershey, PA 17033, USA. shayes1@hmc.psu.edu
Shawn G
SG
Hayes
Jennifer L
JL
McCord
Marc P
MP
Kaufman
D000255:Adenosine Triphosphate / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D017704:Baroreflex / Q000187:drug effects; D001794:Blood Pressure; D002211:Capsaicin / Q000008:administration & dosage; D002415:Cats; D002628:Chemoreceptor Cells / Q000187:drug effects / Q000378:metabolism*; D006339:Heart Rate; D007269:Injections, Intra-Arterial; D008297:Male; D009119:Muscle Contraction; D009121:Muscle Denervation; D018482:Muscle, Skeletal / Q000187:drug effects / Q000294:innervation / Q000378:metabolism*; D010791:Phrenic Nerve / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D012123:Pulmonary Ventilation; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2 / Q000378:metabolism*; D012584:Sciatic Nerve / Q000601:surgery; D014544:Uridine Triphosphate / Q000008:administration & dosage / Q000378:metabolism
D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D002211:Capsaicin; D014544:Uridine Triphosphate