Pituitary blood flow

1982 ◽  
Vol 243 (6) ◽  
pp. E427-E442 ◽  
Author(s):  
R. B. Page
Keyword(s):  
Blood Flow ◽  
Median Eminence ◽  
Three Dimensional ◽  
Vascular Anatomy ◽  
Flow Regulation ◽  
Organ Blood Flow ◽  
Regional Control ◽  
New Concepts ◽  
Insight Into

The direction of pituitary blood flow, the amount of pituitary blood flow, its regional control, and the role of the median eminence microcirculation are the subjects of this review. Present concepts of pituitary blood flow are focused almost entirely on its direction and arouse from studies of pituitary vascular anatomy performed almost 50 years ago. The development of new anatomic techniques has led to a reappraisal of pituitary angioarchitecture, stimulated physiological studies to clarify the pattern of blood flow within the entire gland, and led to a reappraisal of accepted concepts of directional pituitary blood flow. The availability of techniques to accurately measure organ blood flow has permitted study of pituitary blood flow; and, when combined with knowledge of pituitary anatomy, the application of these techniques promises to provide a means to develop insight into control of the mechanisms by which chemical messengers are delivered to the pituitary to control its function. New anatomic techniques promise to develop new understanding of the three-dimensional arrangement of median eminence microvasculature and yield new concepts of blood flow regulation within the median eminence that can be tested by physiological means.

scholarly journals The distribution of myosin II in Dictyostelium discoideum slug cells.

1991 ◽  
Vol 115 (5) ◽  
pp. 1267-1274 ◽  
Author(s):  
S Eliott ◽  
P H Vardy ◽  
K L Williams
Keyword(s):  
Cell Motility ◽  
Dictyostelium Discoideum ◽  
Immunofluorescence Microscopy ◽  
Molecular Genetic ◽  
Myosin Ii ◽  
Three Dimensional ◽  
Homogeneous Distribution ◽  
Multicellular Development ◽  
Insight Into

While the role of myosin II in muscle contraction has been well characterized, less is known about the role of myosin II in non-muscle cells. Recent molecular genetic experiments on Dictyostelium discoideum show that myosin II is necessary for cytokinesis and multicellular development. Here we use immunofluorescence microscopy with monoclonal and polyclonal antimyosin antibodies to visualize myosin II in cells of the multicellular D. discoideum slug. A subpopulation of peripheral and anterior cells label brightly with antimyosin II antibodies, and many of these cells display a polarized intracellular distribution of myosin II. Other cells in the slug label less brightly and their cytoplasm displays a more homogeneous distribution of myosin II. These results provide insight into cell motility within a three-dimensional tissue and they are discussed in relation to the possible roles of myosin II in multicellular development.

scholarly journals Role of Perfusion Pressure in Major Organ Blood Flow during Cardiopulmonary Bypass in Canines

2000 ◽  
Vol 39 (5) ◽  
pp. 748
Author(s):  
Young Lan Kwak ◽  
Young Hwan Park ◽  
Sang Beom Nam ◽  
Young Jun Oh ◽  
Seung Ho Kim ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiopulmonary Bypass ◽  
Perfusion Pressure ◽  
Organ Blood Flow ◽  
Major Organ

Retinal Vascular Implications of Ocular Hypertension

2021 ◽  
Author(s):  
Fidan Jmor ◽  
John C. Chen
Keyword(s):  
Blood Flow ◽  
Diabetic Retinopathy ◽  
Intraocular Pressure ◽  
Vascular Anatomy ◽  
Flow Regulation ◽  
Retinal Blood Flow ◽  
Vein Occlusion ◽  
Ocular Perfusion ◽  
The Relationship ◽  
Central Retinal Vein

In this chapter, we review the basics of retinal vascular anatomy and discuss the physiologic process of retinal blood flow regulation. We then aim to explore the relationship between intraocular pressure and retinal circulation, taking into account factors that affect retinal hemodynamics. Specifically, we discuss the concepts of ocular perfusion pressure, baro-damage to the endothelium and transmural pressure in relation to the intraocular pressure. Finally, we demonstrate the inter-relationships of these factors and concepts in the pathogenesis of some retinal vascular conditions; more particularly, through examples of two common clinical pathologies of diabetic retinopathy and central retinal vein occlusion.

Protective role of NO in the regional hemodynamic changes during acute endotoxemia in rats

1994 ◽  
Vol 266 (4) ◽  
pp. H1558-H1564 ◽  
Author(s):  
M. F. Mulder ◽  
A. A. van Lambalgen ◽  
E. Huisman ◽  
J. J. Visser ◽  
G. C. van den Bos ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vascular Resistance ◽  
Systemic Blood Pressure ◽  
Saline Group ◽  
Protective Role ◽  
Organ Blood Flow ◽  
Organ Perfusion ◽  
Hemodynamic Changes ◽  
Systemic Blood

The role of NO during the first hour of endotoxemia is still controversial. To evaluate whether NO is protective or detrimental to the regulation of systemic blood pressure, cardiac output (CO), and organ perfusion in rats during acute endotoxemia, we have studied the effects of inhibition of NO synthesis. Thirty minutes after 0.1 mg NG-nitro-L-arginine (L-NNA; group L, n = 7, partial inhibition), 1 mg L-NNA (group H, n = 6, complete inhibition), or saline (group E, n = 7) intravenous infusion, anesthetized volume-loaded rats were infused with endotoxin Escherichia coli O127:B8 (8 mg.kg-1 x h-1) from time (t) = 0 to 60 min. Organ blood flow was measured with radioactive microspheres. In group H, at time 0, CO was lower than in group E (by -29%; P < 0.05), and systemic vascular resistance (SVR) was higher than in groups E and L (by 72 and 51%, respectively; P < 0.05). Perfusion of the pancreas, stomach, intestines, and kidney was lower (P < 0.05) and corresponding organ vascular resistance (OVR) higher (P < 0.05) in group H than in groups E and L (except kidney in group L). At t = 60 min, in groups H and L, CO was lower (by -45 and -26%, respectively; P < 0.05) and SVR was higher (by 112 and 54%, respectively; P < 0.05) than in group E. In group L only blood flow to the heart, pancreas, intestines, and kidney was significantly lower than in group E, and corresponding OVR was higher.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of oxygen on blood flow autoregulation in cat sartorius muscle

1981 ◽  
Vol 241 (6) ◽  
pp. H807-H815 ◽  
Author(s):  
S. M. Sullivan ◽  
P. C. Johnson
Keyword(s):  
Blood Flow ◽  
Perfusion Pressure ◽  
Important Determinant ◽  
Flow Regulation ◽  
Sartorius Muscle ◽  
Gas Mixture ◽  
Pressure Reduction ◽  
Effect Of Oxygen ◽  
Arteriolar Diameter

To assess the role of O2 in blood flow autoregulation, arteriolar diameter and erythrocyte velocity were measured in individual microvessels of the cat sartorius muscle while ambient O2 tension (PO2) and perfusion pressure were altered. The muscle surface was covered with a layer of silicone fluid equilibrated with a gas mixture containing 0—20% O2. Under control conditions (0% O2) all except the largest arterioles dilated with pressure reduction, and all showed significant blood flow autoregulation. Elevated PO2 diminished flow regulation and dilation in large and small arterioles when arterial pressure was reduced. This effect was generally more pronounced in the small arterioles where elevated PO2 caused complete cessation of blood flow. Complete blood flow stoppage was not routinely seen in larger vessels and may reflect the fact that these vessels also supply deeper tissue regions less affected by the change in ambient PO2. Our results indicate that the PO2 level of the tissue may be an important determinant in blood flow autoregulation.

Role of Endothelin-1 in Choroidal Blood Flow Regulation during Isometric Exercise in Healthy Humans

2003 ◽  
Vol 44 (2) ◽  
pp. 728 ◽  
Author(s):  
Gabriele Fuchsja¨ger-Mayrl ◽  
Alexandra Luksch ◽  
Magdalena Malec ◽  
Elzbieta Polska ◽  
Michael Wolzt ◽  
...  
Keyword(s):  
Blood Flow ◽  
Isometric Exercise ◽  
Flow Regulation ◽  
Choroidal Blood Flow ◽  
Endothelin 1 ◽  
Healthy Humans ◽  
Blood Flow Regulation

scholarly journals Role of Computational Methods in Going beyond X-ray Crystallography to Explore Protein Structure and Dynamics

2018 ◽  
Vol 19 (11) ◽  
pp. 3401 ◽  
Author(s):  
Ashutosh Srivastava ◽  
Tetsuro Nagai ◽  
Arpita Srivastava ◽  
Osamu Miyashita ◽  
Florence Tama
Keyword(s):  
Protein Dynamics ◽  
Computational Methods ◽  
Protein Structures ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
X Ray ◽  
X Ray Crystallography ◽  
Insight Into

Protein structural biology came a long way since the determination of the first three-dimensional structure of myoglobin about six decades ago. Across this period, X-ray crystallography was the most important experimental method for gaining atomic-resolution insight into protein structures. However, as the role of dynamics gained importance in the function of proteins, the limitations of X-ray crystallography in not being able to capture dynamics came to the forefront. Computational methods proved to be immensely successful in understanding protein dynamics in solution, and they continue to improve in terms of both the scale and the types of systems that can be studied. In this review, we briefly discuss the limitations of X-ray crystallography in studying protein dynamics, and then provide an overview of different computational methods that are instrumental in understanding the dynamics of proteins and biomacromolecular complexes.

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