The possible role of pedunculopontine tegmental nucleus (PPT) opioid receptors in the cardiovascular responses in normotensive and hemorrhagic hypotensive rats.
Mohammad Naser Shafei, Omid Fakharzadeh Moghaddam, Vida Alikhani, Reza Mohebbati
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引用次数: 1
Abstract
Background: The pedunculopontine tegmental nucleus (PPT) is involved in cardiovascular regulation. The presence of mu (μ) opioid receptors in the PPT nucleus has been determined. In the present study, the role of this nucleus in normotensive conditions and then the role of these receptors on cardiovascular function in hypotension induced by hemorrhage (HEM) were investigated.
Method: Animals were divided into the following groups: Group 1: control, Group 2: HEM, Group 3: morphine at dose 100 nmol (a general opioid receptor agonist), Group 4: naloxone at dose 100 nmol (a general opioid receptor antagonist), Group 5: morphine + HEM, and Group 6: naloxone + HEM. After anesthesia, two femoral arteries were cannulated to record the cardiovascular parameters and blood withdrawal. Two minutes after induction of HEM, drugs were injected into the nucleus, and cardiovascular parameters were measured. Changes (Δ) in cardiovascular responses due to drug injection and HEM were calculated and compared to control and HEM groups.
Results: HEM significantly reduced changes in systolic and mean arterial pressures and increased heart rate changes compared to control. Morphine microinjection in normotensive and HEM rats significantly decreased systolic blood pressure, mean arterial pressure, and heart rate, and naloxone significantly increased all these parameters.
Conclusion: This study showed that the PPT nucleus plays a role in modulating the cardiovascular responses induced by HEM. The µ opioid receptor of the PPT nucleus in the normotensive and HEM rats have inhibitory effects on blood pressure and heart rate mainly, and these effects are eliminated by naloxone microinjection.
期刊介绍：
Clinical and Experimental Hypertension is a reputable journal that has converted to a full Open Access format starting from Volume 45 in 2023. While previous volumes are still accessible through a Pay to Read model, the journal now provides free and open access to its content. It serves as an international platform for the exchange of up-to-date scientific and clinical information concerning both human and animal hypertension. The journal publishes a wide range of articles, including full research papers, solicited and unsolicited reviews, and commentaries. Through these publications, the journal aims to enhance current understanding and support the timely detection, management, control, and prevention of hypertension-related conditions.
One notable aspect of Clinical and Experimental Hypertension is its coverage of special issues that focus on the proceedings of symposia dedicated to hypertension research. This feature allows researchers and clinicians to delve deeper into the latest advancements in this field.
The journal is abstracted and indexed in several renowned databases, including Pharmacoeconomics and Outcomes News (Online), Reactions Weekly (Online), CABI, EBSCOhost, Elsevier BV, International Atomic Energy Agency, and the National Library of Medicine, among others. These affiliations ensure that the journal's content receives broad visibility and facilitates its discoverability by professionals and researchers in related disciplines.
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