Modulation of blood pressure by substance P: opposite effects of N- and C- terminal fragments on anesthetized rats.
Considerable evidence suggests that substance P (SP) may be a transmitter mediating the depressor effects of baroreceptor reflex activation within the brainstem, yet intracerebroventricular administration of SP is reported to result in a pronounced pressor effect. In this study, SP injected into the 4th cerebral ventricle produced a biphasic effect; a brief decrease in blood pressure followed by a lengthy increase. Similar injections of a carboxy-terminal fragment of SP produced only a pressor effect of long duration. Injection of an amino-terminal SP fragment produced only a brief, rapid depressor effect. These results suggest that the amino-terminal sequence of SP may be involved in mediating the depressor effects of baroreceptor activation.
D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology*; D011311:Pressoreceptors / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000494:pharmacology*; D013997:Time Factors
D010446:Peptide Fragments; D013373:Substance P; C036877:substance P (1-7)