The coronary effects of parathyroid hormone.
OBJECTIVE
The aim of the present study was to characterize the role of the ATP-sensitive potassium channels (K(+)(ATP)) in the coronary dilator action of parathyroid hormone (PTH).


METHODS
Dose-response curves of intracoronary administrated PTH (0.15-1.33 nmol) were obtained in control phases and during continuous intracoronary administration of the K(+)(ATP) channel-selective antagonist glibenclamide (0.1-1.0 micromol/min) in dogs (n = 13).


RESULTS
Increments of integrated coronary conductance (excess coronary conductance) at PTH doses of 0.15 and 1.33 nmol were 1.17 versus 0.03 ml/mm Hg (p < 0.05) and 4.03 versus 0.94 ml/mm Hg (p < 0.05) in the control versus during maximal blockade, respectively.


CONCLUSIONS
The results indicate that the activation of K(+)(ATP) channels significantly contributes to the PTH-induced coronary vasodilation.
Fazekas
Réka
R
Department of Cardiovascular Surgery, Semmelweis University Budapest, Budapest, Hungary.
Soós
Pál
P
Kékesi
Violetta
V
Fazekas
Levente
L
Juhász-Nagy
Alexander
A
D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D002417:Cattle; D003331:Coronary Vessels / Q000187:drug effects / Q000502:physiology*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D005905:Glyburide / Q000494:pharmacology; D008297:Male; D010281:Parathyroid Hormone / Q000008:administration & dosage / Q000494:pharmacology / Q000502:physiology*; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*
D010281:Parathyroid Hormone; D010446:Peptide Fragments; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D000255:Adenosine Triphosphate; D005905:Glyburide