Vasopressor effects of substance P and C-terminal sequences after intracisternal injection to alpha-chloralose-anaesthetized rats: blockade by a substance P antagonist.
Substance P (SP) and the C-terminal sequences octa- and penta-SP produced dose-dependent vasopressor responses, and the action was associated with mild tachycardia. The vasopressor effect of SP was counteracted by the SP antagonist [D-Pro2,D-Phe7,D-Trp9]SP given intracisternally, suggesting that central SP receptors were involved. Experiments with different sodium contents in the vehicle and with naloxone pretreatment indicate that central naloxone-sensitive opiate receptors may exist, capable of modulating the effects of SP receptor activation.
D000595:Amino Acid Sequence; D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002698:Chloralose; D002946:Cisterna Magna; D007267:Injections; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D010446:Peptide Fragments; D002698:Chloralose; D013373:Substance P