scholarly journals Autoregulation in the Middle Meningeal Artery

1996 ◽  
Vol 16 (3) ◽  
pp. 507-516 ◽  
Author(s):  
J. Michalicek ◽  
V. Gordon ◽  
G. Lambert

In cats anesthetized with α-chloralose, auto-regulation of blood flow (F) in the middle meningeal and common carotid arteries was assessed by bleeding and subsequently reinfusing the animals to achieve a 25% step reduction in mean arterial blood pressure (P), while maintaining the systolic blood pressure >80 mmHg. The integrity of autoregulation was assessed by calculating the gain factor Gf = 1 — [(ΔF/F)/(ΔP/P)]. Cats were examined intact, after hexamethonium (10 mg/kg), and after papaverine (6 mg/kg). Reduction of blood pressure of 25 to 60 mmHg produced equivalent drops in carotid blood flow ( Gf = 0.041 ± 0.34; mean ± standard deviation, n = 12). There were only small changes in flow in the middle meningeal artery during this procedure ( Gf = 0.91 ± 0.29). Hexamethonium did not block autoregulation in the middle meningeal artery ( Gf = 0.92 ± 0.13, n = 4). However, papaverine almost completely abolished the ability of the artery to autoregulate ( Gf = 0.10 ± 0.16, n = 7). The results suggest that the middle meningeal artery possesses an ability similar to that of the cortical circulation to autoregulate its blood flow through intrinsic, non-neuronal mechanisms. This will have important implications for the study of disturbances of dural arterial control in migraine and other headaches.

Cephalalgia ◽  
1989 ◽  
Vol 9 (9_suppl) ◽  
pp. 41-46
Author(s):  
Marion J Perren ◽  
Wasyl Feniuk ◽  
Patrick Pa Humphrey

The haemodynamic effects of the selective 5-HT1-like agonist GR43175 have been compared with that of ergotamine in anaesthetized cats. Both GR43175 (30–1000 μg/kg intravenously) and ergotamine (0.3–30 μg/kg intravenously) caused a dose-dependent reduction in the proportion of cardiac output passing through arteriovenous anastomoses (AVAs). However, unlike GR43175, the effect of ergotamine (30 μg/kg intravenously) was associated with marked increases in diastolic blood pressure and total peripheral resistance. In further studies, the effect of GR43175 on the distribution of blood flow within the carotid bed has been examined. GR43175 caused a reduction in total carotid arterial blood flow which was entirely due to a reduction in flow through carotid AVAs. These results demonstrate that GR43175, unlike ergotamine, has a highly selective vasoconstrictor action on AVAs within the cranial circulation of anaesthetized cats. Such a mechanism may be important in its antimigraine activity.


2015 ◽  
Vol 12 (3) ◽  
pp. 30-33
Author(s):  
L V Melnikova ◽  
L F Bartosh ◽  
O A Grechishkina

Aim. To study changes in structural and functional features of the common carotid arteries and central hemodynamic parameters under the influence of fosinopril at hypertensive patients depending on achieving target blood pressure.Material and methods. The study included 116 patients with essential hypertension. All patients underwent a general clinical study, an ultrasound scan of the common carotid arteries (CCA ) with the assessment of the structure and intravascular blood flow, and echocardiography with the definition of the parameters of central hemodynamic and intravascular, ambulatory blood pressure monitoring (ABPM) before the study and after 24 weeks of antihypertensive therapy angiotensin - converting enzyme fosinopril. Two groups of patients: the first group consisted of 74 people with the achievement of the targets of blood pressure (BP), the second 42 people who have not been achieved target BP levels.Results. In the first group there was a statistically significant decrease in the proportion of peripheral resistance, increased systolic index, distensibility coefficient of the common carotid arteries peak flow velocity. In the second group specific peripheral resistance was significantly increased, the thickness of the intima-media increased, decreased peak flow velocity.Conclusion. Effectiveness depends on fosinopril initial state total peripheral resistance, cardiac output, structural and functional features elastic arteries.


1982 ◽  
Vol 52 (5) ◽  
pp. 1138-1146 ◽  
Author(s):  
M. A. Baker ◽  
M. J. Hawkins ◽  
R. D. Rader

Common carotid blood flow (CCBF) and respiratory water loss (RWL) were measured in dogs resting at ambient temperatures between 25 and 50 degrees C, during hypothalamic heating, and during light and heavy exercise at ambient temperatures of 25 and 35 degrees C. In resting dogs, CCBF varied with the level of RWL. Elevations in CCBF and RWL occurred within seconds of each other during bursts of panting. Mean unilateral CCBF increased from 6.2 ml . min-1 . kg-1 at 25 degrees C to 16.8 ml . min-1 . kg-1 at 45 degrees C, in parallel with increasing RWL. Hypothalamic heating elicited simultaneous elevations in CCBF and RWL, and the level of CCBF was strongly correlated with the hypothalamic temperature. Both CCBF and RWL increased rapidly at the onset of exercise and continued to rise during a 15-min run. Highest rates of blood flow and evaporation occurred during heavy exercise at 35 degrees C. It is concluded that the rate of blood flow through the common carotid arteries in the dog is related to the thermoregulatory needs of the animal, and most of the increased flow occurring during heat stress is destined for evaporative surfaces of the nose, mouth, and tongue.


1971 ◽  
Vol 49 (5) ◽  
pp. 420-426 ◽  
Author(s):  
Paul F. Mercer

Renal function was studied in rats before and after section of the vagus nerves at the level of the common carotid arteries. In the control group of rats, sodium output and volume rate of urine flow increased following vagal section but glomerular filtration rate did not change. This response was not altered in other rats by desoxycorticosterone acetate, vasopressin, or renal nerve section. This response was similar to that seen in rats in which both common carotid arteries had been occluded. The natriuresis following bilateral vagotomy did not occur in rats in which the blood pressure was prevented from rising by means of aortic constriction. It is concluded that a natriuresis does occur following bilateral vagotomy. This natriuresis may be a result of the effect of arterial blood pressure following the vagotomy.


1974 ◽  
Vol 48 (s2) ◽  
pp. 259s-260s ◽  
Author(s):  
A. Malliani ◽  
F. Lombardi ◽  
M. Pagani ◽  
G. Recordati ◽  
P. J. Schwartz

1. In vagotomized anaesthetized cats with both common carotid arteries occluded, stretch of the thoracic aorta induced reflex increases in arterial blood pressure, heart rate and left ventricular dP/dtmax.. Similar responses were obtained in cats with spinal transection at the level of the first cervical nerve roots. 2. The hypothesis is advanced that sympathetic excitatory reflexes may contribute to the maintenance of hypertension through positive feedback.


2021 ◽  
Vol 10 (Supplement_1) ◽  
Author(s):  
D Serova ◽  
V Serov ◽  
A Braun ◽  
A Kovalenko ◽  
A Shutov

Abstract Funding Acknowledgements Type of funding sources: None. Introduction A negative effect on the prognosis of ischemic stroke of the aggressive decrease in blood pressure, leading to a decrease in cerebral blood flow, is known. On the other side, increased blood pressure can be a compensatory mechanism. Currently, however, it is difficult to assess the adequacy of cerebral blood flow, one of the indicators of which is the blood flow velocity in the common carotid artery. Purpose The aim of this study was to estimate the peak systolic velocity in the common carotid arteries (CCA PSV) depending on the severity of acute ischemic stroke (IS). Methods 180 patients with acute ischemic stroke (70 females and 110 males, mean age was 66.3 ± 12.3 years) were studied. Including 46 (25.6%) patients with cardioembolic stroke, 25 (13.9%) - with a thrombotic stroke, 27 (15.0%) – with a lacunar stroke and 82 (45.5%) – with undifferentiated stroke. Most of them 173 (96.1%) had grade 3 of arterial hypertension according to ESH/ESC Guidelines for the management of arterial hypertension, 2018. 59 (32.8%) patients had coronary artery disease, 52 (28.9%) - had atrial fibrillation. Patients were categorized according to National Institutes of Health Stroke Scale (NIHSS) severity in mild NIHSS (<9) - 122 (67.8%) patients, moderate NIHSS (9–15) - 35 (19.4%) patients, and severe stroke NIHSS (>16) - 23 (12.8%) patients.  Median NIHSS score was 9.2 ± 0.9. All patients underwent a transthoracic echocardiography and a carotid ultrasound examination. A comparative assessment of echographic parameters was performed in patients of lower (NIHSS score ≤ 4.0) and upper (NIHSS score≥11.0) quartile according to the NIHSS score. Results It is shown a decrease of peak systolic velocity in the common carotid arteries with an increase in the severity of IS on the NIHSS scale: in mild stroke, it was 73.9 ± 18.7 cm/s, in moderate stroke - 66.3 ± 19.2 cm/s (p = 0.04), in severe stroke - 62.1 ± 17,4 cm/sec (p = 0.006 and p = 0.4, respectively). Peak systolic velocity in patients with the lower quartile of stroke severity was 73.8 ± 19.1 cm/sec, in the group of patients with the upper quartile – 64.3 ± 19.2 cm/sec (р=0.02). There were no differences in the resistance index of common carotid arteries: 0.75 ± 0.05, 0.76 ± 0.06 and 0.75 ± 0.07 for mild, moderate and severe severity, respectively, p > 0.5). A multiple linear regression analysis in which the severity of ischemic stroke on the NIHSS scale was a dependent variable and age, CCA PSV, common carotid artery intima–media thickness and systolic, diastolic and pulse blood pressure were independent variables, showed that the severity of ischemic stroke was independently correlated with the CCA PSV (β =-0.13, p = 0.009). Conclusions.1. It is shown the decrease of peak systolic velocity in the common carotid arteries with an increase in the severity of ischemic stroke on the NIHSS scale. 2. The reduction of CCA PSV exacerbates brain ischemia and reflecting disorders of autoregulation of cerebral blood flow.


1941 ◽  
Vol 74 (1) ◽  
pp. 29-40 ◽  
Author(s):  
Philip D. McMaster

Advantage has been taken of the relative transparency of the claw of the mouse to devise a method, here described, to measure the blood pressure in the animal's leg. Direct measurements of the systolic blood pressure from the carotid arteries of anesthetized mice have also been made. Simultaneous blood pressure readings by both these methods applied to the same animal showed close agreement. The systolic pressure ranged from 60 to 126 mm. Hg, according to the conditions.


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