Related Experiment Video
Updated: Dec 8, 2025

Standardized Hemorrhagic Shock Induction Guided by Cerebral Oximetry and Extended Hemodynamic Monitoring in Pigs
Published on: May 21, 2019
Cardiovascular Effect of Cuneiform Nucleus During Hemorrhagic Hypotension
Reza Mohebbati1, Mahmoud Hosseini2, Majid Khazaei1
1Department of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Introduction:
The underlying mechanism responsible for the cardiovascular response to Hemorrhage (HEM) is still unknown; however, several brain areas, such as the Cuneiform nucleus (CnF) have shown to be involved. In this study, the cardiovascular effect of the CnF during HEM was evaluated.
Methods:
The animals were divided into the following groups: 1. Vehicle; 2. HEM; 3. Cobalt chloride (CoCl2); 4. CoCl2+saline; and 5. CoCl2+HEM. Catheterization of the left and right femoral artery was performed to record blood pressure and blood withdrawal, respectively. Saline and CoCl2 were microinjected into the CnF nucleus, and then blood withdrawal was done for HEM induction. Cardiovascular regulation throughout the experiments was recorded and changes (Δ) in the Systolic Blood Pressure (SBP), Mean Arterial Pressure (MAP) and Heart Rate (HR) were calculated over time and compared with those treated with saline and HEM, using repeated-measures ANOVA.
Results:
HEM significantly reduced ΔSBP and ΔMAP and augmented ΔHR than the vehicle group. CoCl2 did not significantly affect basic ΔSBP, ΔMAP, and ΔHR compared with the vehicle group. However, injection of CoCl2 into the CnF before HEM (CoCl2+HEM group) significantly decreased ΔSBP, ΔMAP, and tachycardia, induced by HEM.
Conclusion:
Our results indicated that blockade of the CnF by CoCl2 significantly reduced the hypotension and tachycardia, induced by HEM indicating the involvement of CnF in cardiovascular regulation during HEM.
Related Concept Videos
Blood Pressure Imbalances and Circulatory Shock
Blood Pressure: Hypertension and Hypotension
Normal blood pressure is 120/80 mm Hg. Elevated blood pressure is 120-129/under 80 mm Hg. Hypertension, warranting treatment at 130/80 mm Hg, is often asymptomatic and can lead to severe cardiovascular events, aneurysms, peripheral arterial disease, chronic renal disease, or cardiac...
Hormonal Regulation of Blood Pressure
Epinephrine and Norepinephrine
The adrenal medulla releases epinephrine and norepinephrine, catecholamines that enhance and extend the sympathetic or "fight or flight" physiological response. These hormones escalate heart rate and the force of contraction...
Antihypertensive Drugs: Vasodilators
Neural Regulation of Blood Pressure
Baroreceptor Reflex
Baroreceptors, located in the carotid sinuses and aortic arch, detect changes in blood pressure. When blood pressure rises, these stretch-sensitive receptors...
Disorders of the Autonomic Nervous System
Raynaud's disease, also known as Raynaud's...
Alterations in Blood Pressure
Hypertension (High blood pressure)
Hypertension occurs when blood pressure readings consistently exceed the normal range. It is diagnosed when systolic blood pressure (the top number, indicating pressure while the heart...

