Substance P Released in the Rostral Brainstem of Cats Interacts With NK- 1 Receptors During Muscle Pressor Response
Document Type
Article
Publication Date
1-1-1997
Description
The release of immunereactive substance P-like substances (irSP) was measured from sites in the rostral brainstem (at a level 1.3 mm anterior to the obex) of anesthetized cats in response to fatiguing isometric contractions using SP antibody-coated glass microprobes. The contractions caused a pressor and tachycardic response. irSP were released from sites in the medial subnucleus of the nucleus tractus solitarius (mNTS), the solitary tract and lateral tegmental field at this level of the brainstem. Injections of the specific NK-1 receptor antagonist, GR 82334, bilaterally into the mNTS significantly reduced the muscle pressor response, while bilateral injections of the SP NK-1 agonist, GR 73632, into the mNTS significantly increased the pressor and tachycardic responses during the contractions. Neither the antagonist nor the agonist, at the doses tested, affected the resting arterial pressure or heart rate. These data indicate that irSP are released from sites n the mNTS during the reflex pathways activated by isometric contractions and that they interact with NK-1 receptors in the area of the raNTS to affect the cardiovascular responses during the muscle pressor reflex.
Citation Information
Williams, C. A.; and Fowler, W. L.. 1997. Substance P Released in the Rostral Brainstem of Cats Interacts With NK- 1 Receptors During Muscle Pressor Response. Neuropeptides. Vol.31(6). 589-600. https://doi.org/10.1016/S0143-4179(97)90005-6 PMID: 9574826 ISSN: 0143-4179