Neuropeptide Y Reduces Dog Coronary Blood Flow by Increased Small Vessel Resistance

1987 ◽  
Vol 73 (s17) ◽  
pp. 6P-6P ◽  
Author(s):  
J. Clarke ◽  
S. Larkin ◽  
O. Osinawa ◽  
G.J. Davies ◽  
K. Taylor ◽  
...  
Keyword(s):  
Blood Flow ◽  
Neuropeptide Y ◽  
Coronary Blood Flow ◽  
Small Vessel ◽  
Vessel Resistance

Neuropeptide Y and coronary vasoconstriction: role of thromboxane A2

1992 ◽  
Vol 263 (4) ◽  
pp. H1045-H1053
Author(s):  
S. E. Martin ◽  
J. T. Kuvin ◽  
S. Offenbacher ◽  
B. M. Odle ◽  
R. E. Patterson
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Neuropeptide Y ◽  
Coronary Blood Flow ◽  
Myocardial Oxygen Consumption ◽  
Thromboxane A2 ◽  
Coronary Resistance ◽  
Txa2 Receptor

We previously reported that coronary constriction following neuropeptide Y (NPY) was alleviated by cyclooxygenase blockade. To determine the role of thromboxane A2 (TxA2), anesthetized dogs received two paired doses of NPY given 2 h apart. Nine control dogs received NPY alone. Nine test dogs received one of three TxA2 receptor antagonists given between the doses of NPY. Also, five dogs received NPY during which prostaglandins were measured. In controls, NPY decreased coronary blood flow and increased aortic pressure; coronary resistance was increased significantly. Heart rate fell, and myocardial oxygen consumption was unchanged. Thromboxane receptor blockers significantly relieved the coronary constrictor effect of NPY. The reduction in coronary blood flow was blunted, while heart rate, first derivative of left ventricular pressure, and myocardial oxygen consumption were unchanged. Alleviation by TxA2 receptor blockade paralleled that reported for cyclooxygenase inhibitors. Also, significant increases in coronary venous TxA2 were seen at the time of maximal increases in coronary resistance, while prostacyclin was unchanged. In summary, TxA2 appears to mediate part of the coronary constrictor effect of NPY.

Neuropeptide Y Reduces Dog Coronary Blood Flow without Reducing Epicardial Coronary Luminal Diameter

1988 ◽  
Vol 74 (s18) ◽  
pp. 8P-9P ◽  
Author(s):  
S. Larkin ◽  
J. Clarke ◽  
B. Keogh ◽  
J Beckett ◽  
A Maseri ◽  
...  
Keyword(s):  
Blood Flow ◽  
Neuropeptide Y ◽  
Coronary Blood Flow ◽  
Luminal Diameter

Mechanism of redistribution of cerebral blood flow during hypercarbia and seizures

1994 ◽  
Vol 266 (5) ◽  
pp. H2074-H2081 ◽  
Author(s):  
M. G. Muhonen ◽  
G. M. Greene ◽  
D. D. Heistad ◽  
C. M. Loftus
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Small Vessel ◽  
Normal Brain ◽  
Arterial Pco2 ◽  
Vessel Resistance ◽  
Collateral Vessels ◽  
Measured Pressure

After occlusion of an artery to the brain, hypercarbia and seizures may produce a paradoxical reduction in cerebral blood flow to the region supplied by collateral vessels. We measured pressure in an occluded branch of the middle cerebral artery and measured regional cerebral blood flow (rCBF) to collateral-dependent cerebrum in dogs (n = 25) to examine hemodynamic mechanisms that account for the reduction in flow. During hypercarbia (arterial PCO2 = 70 +/- 5 mmHg), rCBF to collateral-dependent cerebrum, measured with microspheres and identified using the shadow flow technique, decreased from 95 +/- 6 (mean +/- SE) to 71 +/- 9 ml.100 g-1.min-1 (P < 0.05), while flow to normal brain increased from 105 +/- 9 to 281 +/- 15 ml.100 g-1.min-1 (P < 0.05). Pressure in a branch of the middle cerebral artery decreased during hypercarbia from 50 +/- 6 to 25 +/- 3 mmHg (P < 0.05), concurrent with a significant increase in resistance of collateral vessels. Small vessel resistance was the same in collateral-dependent and normal brain. During bicuculline-induced seizures, with blood pressure maintained at control levels by withdrawal of blood, rCBF decreased in collateral-dependent cerebrum from 128 +/- 16 to 67 +/- 11 ml.100 g-1.min-1 (P < 0.05), and flow to normal brain increased from 169 +/- 14 to 418 +/- 17 ml.100 g-1.min-1 (P < 0.05). Small vessel resistance decreased in both regions, but the decrease was much greater in normal cerebrum. Changes in cerebral artery pressure and resistance of collateral vessels during seizure were similar to those during hypercarbia.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The effects of neuropeptide Y on myocardial contractility and coronary blood flow

1991 ◽  
Vol 104 (1) ◽  
pp. 195-201 ◽  
Author(s):  
Sonia J. Awad ◽  
Rosemarie Einstein ◽  
Erica K. Potter ◽  
Desmond P. Richardson
Keyword(s):  
Blood Flow ◽  
Neuropeptide Y ◽  
Coronary Blood Flow ◽  
Myocardial Contractility

METHODOLOGICAL ASPECTS OF VISUALIZATION OF CORONARY ARTERIES WITH TRANSTHORACIC ECHOCARDIOGRAPHY

2018 ◽  
pp. 26-35
Author(s):  
Z. A. Agaeva ◽  
K. B. Baghdasaryan
Keyword(s):  
Blood Flow ◽  
Coronary Blood Flow ◽  
Coronary Arteries ◽  
Transthoracic Echocardiography ◽  
Second Harmonic ◽  
Anatomic Reconstruction ◽  
High Quality ◽  
Acoustic Window ◽  
Methodological Aspects

The transthoracic echocardiography made by multifrequency probes with support of the mode of the second harmonic imaging, is a competitive method for visualization of the main coronary arteries and allows to estimate coronary blood flow with high quality. Of course, the method has considerable restrictions, most important of which is the low spatial resolution of a method, due to small acoustic window. Because of this the transthoracic visualization of coronary arteries perhaps will not become the leading method of anatomic reconstruction of separately taken coronary artery and especially all coronary arteries system. However uniqueness and indisputable advantage of this method is an opportunity to noninvasively estimate a coronary blood flow both once, and in dynamics.

Sign in / Sign up

Export Citation Format

Share Document