Glutamate receptors within the lateral periaqueductal gray (lPAG): Effects on blood pressure and heart rate in basic and hypotensive hemorrhagic rats

Objective(s): The lateral periaqueductal gray (lPAG) is involved in regulating cardiovascular activity. As glutamate is present in this region, the effect of glutamatergic receptors on cardiovascular functions in basic and hypotensive hemorrhagic (Hem) rats was investigated.Materials and Methods: In...

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Main Authors: Vida Alikhani, Reza Mohebbati, Mohammad Naser Shafei
Format: Article
Language:English
Published: Mashhad University of Medical Sciences 2025-04-01
Series:Iranian Journal of Basic Medical Sciences
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Online Access:https://ijbms.mums.ac.ir/article_25563_c07b12fced41880672f0e0c7d77b6a1a.pdf
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author Vida Alikhani
Reza Mohebbati
Mohammad Naser Shafei
author_facet Vida Alikhani
Reza Mohebbati
Mohammad Naser Shafei
author_sort Vida Alikhani
collection DOAJ
description Objective(s): The lateral periaqueductal gray (lPAG) is involved in regulating cardiovascular activity. As glutamate is present in this region, the effect of glutamatergic receptors on cardiovascular functions in basic and hypotensive hemorrhagic (Hem) rats was investigated.Materials and Methods: In both basic and hemorrhagic animals, saline, L-glutamate (L-Glu), and ionotropic receptor antagonists (MK-801 and GYK as NMDA and non-NMDA receptor antagonists, respectively) with and without L-Glu microinjected into the lPAG. The heart rate (HR), mean arterial pressure (MAP), and systolic blood pressure (SBP) were captured, and those changes (Δ) were calculated and analyzed.Results: The results showed that in basic conditions, microinjection of MK-801 and GYK alone did not significantly affect cardiovascular parameters, but L-Glu significantly increased all parameters (P<0.001). However, co-injection of GYK and L-Glu significantly attenuated cardiovascular responses induced by L-Glu (P<0.01), whereas MK-801 did not have effects. In Hem hypotensive condition, injection of MK-801 and GYK alone could not significantly change the cardiovascular responses, while L-Glu alone significantly increased these responses (P<0.001). In this condition, Co-injection of L-Glu with GYK attenuates the pressor effect of L-Glu, but MK-801 did not affect it. Conclusion: Findings suggest an excitatory cardiovascular role of the glutamatergic system of lPAG in normotensive conditions mediated by a non-NMDA receptor. However, in hem hypotensive conditions, the endogenous glutamatergic system of lPAG does not affect hem hypotension, while exogenous glutamate via a non-NMDA receptor could improve cardiovascular responses in this condition.
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spelling doaj-art-bc788709b4d84b22ba70235affe879092025-08-20T02:48:06ZengMashhad University of Medical SciencesIranian Journal of Basic Medical Sciences2008-38662008-38742025-04-0128448649210.22038/ijbms.2025.80366.1739925563Glutamate receptors within the lateral periaqueductal gray (lPAG): Effects on blood pressure and heart rate in basic and hypotensive hemorrhagic ratsVida Alikhani0Reza Mohebbati1Mohammad Naser Shafei2Department of Physiology, Faculty of Medicine, Gonabad University of Medical Sciences, Gonabad, IranDepartment of Physiology, Faculty of Medicine, Gonabad University of Medical Sciences, Gonabad, IranDepartment of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, IranObjective(s): The lateral periaqueductal gray (lPAG) is involved in regulating cardiovascular activity. As glutamate is present in this region, the effect of glutamatergic receptors on cardiovascular functions in basic and hypotensive hemorrhagic (Hem) rats was investigated.Materials and Methods: In both basic and hemorrhagic animals, saline, L-glutamate (L-Glu), and ionotropic receptor antagonists (MK-801 and GYK as NMDA and non-NMDA receptor antagonists, respectively) with and without L-Glu microinjected into the lPAG. The heart rate (HR), mean arterial pressure (MAP), and systolic blood pressure (SBP) were captured, and those changes (Δ) were calculated and analyzed.Results: The results showed that in basic conditions, microinjection of MK-801 and GYK alone did not significantly affect cardiovascular parameters, but L-Glu significantly increased all parameters (P<0.001). However, co-injection of GYK and L-Glu significantly attenuated cardiovascular responses induced by L-Glu (P<0.01), whereas MK-801 did not have effects. In Hem hypotensive condition, injection of MK-801 and GYK alone could not significantly change the cardiovascular responses, while L-Glu alone significantly increased these responses (P<0.001). In this condition, Co-injection of L-Glu with GYK attenuates the pressor effect of L-Glu, but MK-801 did not affect it. Conclusion: Findings suggest an excitatory cardiovascular role of the glutamatergic system of lPAG in normotensive conditions mediated by a non-NMDA receptor. However, in hem hypotensive conditions, the endogenous glutamatergic system of lPAG does not affect hem hypotension, while exogenous glutamate via a non-NMDA receptor could improve cardiovascular responses in this condition.https://ijbms.mums.ac.ir/article_25563_c07b12fced41880672f0e0c7d77b6a1a.pdfcardiovascular systemglutamatehemorrhagelateral periaqueductal graynon-nmda receptor
spellingShingle Vida Alikhani
Reza Mohebbati
Mohammad Naser Shafei
Glutamate receptors within the lateral periaqueductal gray (lPAG): Effects on blood pressure and heart rate in basic and hypotensive hemorrhagic rats
Iranian Journal of Basic Medical Sciences
cardiovascular system
glutamate
hemorrhage
lateral periaqueductal gray
non-nmda receptor
title Glutamate receptors within the lateral periaqueductal gray (lPAG): Effects on blood pressure and heart rate in basic and hypotensive hemorrhagic rats
title_full Glutamate receptors within the lateral periaqueductal gray (lPAG): Effects on blood pressure and heart rate in basic and hypotensive hemorrhagic rats
title_fullStr Glutamate receptors within the lateral periaqueductal gray (lPAG): Effects on blood pressure and heart rate in basic and hypotensive hemorrhagic rats
title_full_unstemmed Glutamate receptors within the lateral periaqueductal gray (lPAG): Effects on blood pressure and heart rate in basic and hypotensive hemorrhagic rats
title_short Glutamate receptors within the lateral periaqueductal gray (lPAG): Effects on blood pressure and heart rate in basic and hypotensive hemorrhagic rats
title_sort glutamate receptors within the lateral periaqueductal gray lpag effects on blood pressure and heart rate in basic and hypotensive hemorrhagic rats
topic cardiovascular system
glutamate
hemorrhage
lateral periaqueductal gray
non-nmda receptor
url https://ijbms.mums.ac.ir/article_25563_c07b12fced41880672f0e0c7d77b6a1a.pdf
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AT mohammadnasershafei glutamatereceptorswithinthelateralperiaqueductalgraylpageffectsonbloodpressureandheartrateinbasicandhypotensivehemorrhagicrats