@article { author = {Hosseiniravesh, Mohammad Reza and Hojati, Vida and Khajavirad, Abolfazl and Shajiee, Hooman and Shafei, Mohammad Naser and Mohebbati, Reza}, title = {Effect of MK-801, an antagonist of NMDA receptor in the pedunculopontine tegmental nucleus, on cardiovascular parameters in normotensive and hydralazine hypotensive rats}, journal = {Iranian Journal of Basic Medical Sciences}, volume = {25}, number = {5}, pages = {569-576}, year = {2022}, publisher = {Mashhad University of Medical Sciences}, issn = {2008-3866}, eissn = {2008-3874}, doi = {10.22038/ijbms.2022.62431.13809}, abstract = {Objective(s): In the present study, the cardiovascular effects of glutamate NMDA receptor of the pedunculopontine tegmental nucleus (PPT) in normotensive and hydralazine (HLZ) hypotensive rats were evaluated. Materials and Methods: In the normotensive condition, MK-801(1 nmol; an NMDA receptor antagonist) and L-glutamate (L-Glu, 50 nmol an agonist) alone and together were microinjected into the nucleus using a stereotaxic device. In hypotensive condition, 2 min after induction of hypotension by HLZ (10 mg/kg, intravenous), drugs, same as in normotensive condition, were microinjected into the PPT. Recorded mean arterial pressure (MAP), systolic blood pressure (SBP), and heart rate (HR) were recorded throughout the experiment by a Power lab apparatus that was connected to a catheter inserted into the femoral arty. The cardiovascular changes (Δ) induced by microinjection drugs were computed and statistically analyzed.Results: In the normotensive condition, L-Glu significantly increased ΔMAP and ΔSBP (P<0.001) and decreased ΔHR (P<0.01) compared with the control. MK-801 alone significantly increased HR (P<0.05) while co-injected with L-Glu + MK-801 it significantly attenuated the L-Glu effect on ΔMAP and ΔSBP but augmented ΔHR (P<0.01). In the hydralazine hypotension condition, L-Glu significantly improved hypotension (P<0.01) and deteriorated bradycardia induced by HLZ (P<0.05). MK-801 alone did not significantly affect ΔMAP, ΔSBP, and ΔHR but when co-injected with L-Glu (L-Glu + MK-801) it could significantly attenuate the cardiovascular effect of L-Glu in the PPT. Conclusion: We found that activation of NMDA receptors of the glutamatergic system in the PPT evoked blood pressure and inhibited HR in both normotensive and hypotensive conditions in rats. }, keywords = {blood pressure,Glutamate,Hypotension,NMDA receptor,Pedunculopontine tegmental nucleus}, url = {https://ijbms.mums.ac.ir/article_20082.html}, eprint = {https://ijbms.mums.ac.ir/article_20082_7e6659e228f8ce6614484ab1645f96dc.pdf} }