Cardiovascular Effects of Dynorphin A (1-13) in Conscious Rats and Its Modulation of Morphine Bradycardia Over Time

摘要

Pharmacological studies with alkaloid and peptide opioid agonists and antagonists have revealed a confusing array of cardiovascular responses that differ according to the opioid ligand used, state of consciousness of experimental animals, site (s) or routes of injection, doses, species, experimental stressors,and other variables 6, 7, 17. Of the many endogenous opioid peptides described to date, the autonomic effects of dynorphin-related peptides are the least studied. Although the short-term cardiovascular effects of dynorphin have been investigated in anesthetized rats following microinjections into discrete brain nuclei 2, as of yet the cardiovascular responses evoked by dynorphin A(1-13) have not been systematically compared following different routes of injection in unanesthetized rats. Therefore, an initial purpose of the present study was to define the short-term cardiovascular actions of dynorphin A (1-13) following its intracerebroventricular (ICV), intravenous (IV) or subcutaneous (SC) injection in unanesthetized rats. keywords: Reprints; Response biology. (kr)