Role of Nitric Oxide in the Response of Capillary Blood Flow in the Rat Tail to Body Heating

1994 ◽  
Vol 47 (2) ◽  
pp. 177-187 ◽  
Author(s):  
Yi Zhang ◽  
Daniel Richardson ◽  
Andrew McCray
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Capillary Blood ◽  
Capillary Blood Flow ◽  
Rat Tail

scholarly journals Comparison between the uptake of nitrous oxide and nitric oxide in the human nose

1998 ◽  
Vol 85 (4) ◽  
pp. 1203-1209 ◽  
Author(s):  
Patrick M. Kelley ◽  
Arthur B. DuBois
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Nitrous Oxide ◽  
Steady State ◽  
Partition Coefficient ◽  
Capillary Blood ◽  
Capillary Blood Flow ◽  
Unidirectional Flow ◽  
Steady State Rate ◽  
State Rate

The absorption of nitrous oxide (N2O) during unidirectional flow was compared with the rate of uptake of nitric oxide (NO). At flow rates of 10, 20, and 60 ml/min from one nostril to the other, with the soft palate closed, the N2O reached a steady-state rate of absorption in 5–15 min. The mean superficial capillary blood flow ( n = 5) calculated from solubility and the steady-state rate of N2O absorption ranged from 13.3 to 15.9 ml/min. The relation between absorption of N2O in the nose and capillary blood flow fits a ventilation-perfusion model used by others to describe uptake of inert, soluble gases in the rat nose. By contrast, the rate of uptake of NO gas, which is chemically reactive, is 25–31 times as great as predicted by just its blood-to-air partition coefficient. Exogenous NO (16.9 parts/million) did not induce nasal vasodilation as measured with laser Doppler and N2O absorption methods. The difference between the measured rate of uptake of NO and the rate of uptake attributable to its partition coefficient in blood at the rate of blood flow calculated from N2O uptake is probably due to chemical reaction of NO in mucous secretions, nasal tissues, and capillary blood.

Maintenance of Pulsatile Lung Capillary Blood Flow: The Role of the Pulmonary Venous System

1974 ◽  
Vol 47 (5) ◽  
pp. 24P-25P
Author(s):  
B. Rajagopalan ◽  
J. Friend ◽  
T. Stallard ◽  
G. de J. Lee
Keyword(s):  
Blood Flow ◽  
Capillary Blood ◽  
Venous System ◽  
Capillary Blood Flow

Role of nitric oxide in intrarenal hemodynamics in experimental diabetes mellitus in rats

1999 ◽  
Vol 277 (3) ◽  
pp. R725-R733 ◽  
Author(s):  
Axel C. Pflueger ◽  
Timothy S. Larson ◽  
Siegfried Hagl ◽  
Franklyn G. Knox
Keyword(s):  
Nitric Oxide ◽  
Diabetes Mellitus ◽  
Blood Flow ◽  
Experimental Diabetes ◽  
Capillary Blood ◽  
Experimental Diabetes Mellitus ◽  
Vasa Recta ◽  
Nondiabetic Control ◽  
Stimulation Of

The role of nitric oxide (NO) in the regulation of the intrarenal microcirculation in streptozotocin (STZ)-induced diabetes mellitus in rats is not clear. We examined renal cortical and papillary hemodynamics in STZ rats and determined the effects of systemic inhibition and stimulation of NO synthesis. Renal blood flow in cortical (QCC), and inner medullary ascending (QAV) and descending (QDV) vasa recta capillaries was measured by fluorescence videomicroscopy in STZ Munich-Wistar rats and nondiabetic control rats. Ten days after STZ injection (80 mg/kg ip), basal QCC and QDV were significantly greater in STZ rats ( n = 16) compared with control rats ( n = 15). Infusion of N G-monomethyl-l-arginine (l-NMMA, 15 mg/kg bolus, 500 μg ⋅ min−1 ⋅ kg−1iv) decreased QCC (−41%), QAV (−38%), and QDV (−37%) in control rats ( n = 6) and to a significantly greater magnitude than in STZ rats ( n = 7), QCC (−14%), QAV (−20%), and QDV (−25%). Coinfusion ofl-arginine (l-Arg, 1 mg ⋅ kg−1 ⋅ min−1iv) with l-NMMA increased QCC to a significantly greater extent ( P < 0.01) in control rats compared with STZ rats. In subsequent studies, infusion ofl-Arg alone increased QCC (+50%), QAV (+16%), and QDV (+11%) in control rats ( n = 5) but had no effect in STZ rats ( n = 5). These results show that the response of renal cortical and papillary capillary blood flow to both inhibition and stimulation of NO synthesis is attenuated in the early onset of STZ-diabetes mellitus rats compared with control rats.

scholarly journals MODERN MEDICAL PROBLEMS OF MICROCIRCULATION AND HYPOXIC SYNDROME

2015 ◽  
Vol 69 (1-2) ◽  
pp. 57-63
Author(s):  
K. P. Ivanov
Keyword(s):  
Blood Flow ◽  
Capillary Blood ◽  
Capillary Blood Flow ◽  
Adaptation To Hypoxia ◽  
Medical Problems ◽  
Complete Adaptation ◽  
Capillary Circulation ◽  
First Time ◽  
The Brain

In this paper long known problems of microcirculation are shown, which were solved only during the last 40 years. They are concerned with the velocity and character of the capillary blood flow, the regulation of the capillary blood flow, the role of various vessels in the oxygen transport, the role of leukocytes in physiology and pathology of the capillary blood flow, with the special features of the function of lungs in supplying the whole organism with oxygen and with bioenergetic laws in the development of an organism adaptation to hypoxia. Here we considered a number of the most important medical problems of microcirculation and hypoxic syndrome. A relatively new factor in the capillary circulation is the fact that in the brain and heart capillaries there are sites with pO2 close to zero. They show that the capillary circulation has no central nervous regulation of the blood flow. The blood flow in these organs obeys only occasional oscillations. The new fact is that Krogh’s rule about metabolism and oxygen exchange occurring only in the capillaries is abandoned. It is shown that almost 30% of consumed oxygen is delivered to the brain via arterioles, which changes our relation to the capillary circulation as a unique mechanism of the tissue supply with oxygen. The new fact is also the mass adhesion of leukocytes to the walls of microvessels, which results in the occlusion of the vessels followed by the development of the heart and brain ischemia. It was shown for the first time that contrary to previous ideas the alveoli in the lungs are supplied with blood from a powerful network of large microvessels from 20 to 50 μm in diameter rather than from thin arterioles. They make possible the passage of 6–12 l of the blood in the norm and during stressed muscle activity — up to 18–23 l of blood per minute. The principle is substantiated that during hypoxia only normal supply of an organism with oxygen may result in a complete adaptation of an organism to the deficit of oxygen.

Lutein Complex Supplementation Increases Ocular Blood Flow Biomarkers in Healthy Subjects

2019 ◽  
Vol 89 (1-2) ◽  
pp. 5-12
Author(s):  
Alon Harris ◽  
Brent Siesky ◽  
Amelia Huang ◽  
Thai Do ◽  
Sunu Mathew ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Diastolic Blood Pressure ◽  
Healthy Subjects ◽  
Ocular Blood Flow ◽  
Capillary Blood ◽  
Post Treatment ◽  
Capillary Blood Flow ◽  
Doppler Imaging ◽  
Retinal Capillary

Abstract. Introduction: To investigate the effects of a lutein complex supplementation on ocular blood flow in healthy subjects. Materials and Methods: Sixteen healthy female patients (mean age 36.8 ± 12.1 years) were enrolled in this randomized, placebo-controlled, double-blinded, two-period crossover study. Subjects received daily an oral dose of the lutein with synergistic phytochemicals complex (lutein (10 mg), ascorbic acid (500 mg), tocopherols (364 mg), carnosic acid (2.5 mg), zeaxanthin (2 mg), copper (2 mg), with synergistic effects in reducing pro-inflammatory mediators and cytokines when administered together in combination) and placebo during administration periods. Measurements were taken before and after three-week supplementation periods, with crossover visits separated by a three-week washout period. Data analysis included blood pressure, heart rate, intraocular pressure, visual acuity, contrast sensitivity detection, ocular perfusion pressure, confocal scanning laser Doppler imaging of retinal capillary blood flow, and Doppler imaging of the retrobulbar blood vessels. Results: Lutein complex supplementation produced a statistically significant increase in mean superior retinal capillary blood flow, measured in arbitrary units (60, p = 0.0466) and a decrease in the percentage of avascular area in the superior (−0.029, p = 0.0491) and inferior (−0.023, p = 0.0477) retina, as well as reduced systolic (−4.06, p = 0.0295) and diastolic (−3.69, p = 0.0441) blood pressure measured in mmHg from baseline. Data comparison between the two supplement groups revealed a significant decrease in systemic diastolic blood pressure (change from pre- to post-treatment with lutein supplement (mean (SE)): −3.69 (1.68); change from pre- to post-treatment with placebo: 0.31 (2.57); p = 0.0357) and a significant increase in the peak systolic velocity (measured in cm/sec) in the central retinal artery (change from pre- to post-treatment with lutein supplement: 0.36 (0.19); change from pre- to post-treatment with placebo: −0.33 (0.21); p = 0.0384) with lutein complex supplement; data analyses from the placebo group were all non-significant. Discussion: In healthy participants, oral administration of a lutein phytochemicals complex for three weeks produced increased ocular blood flow biomarkers within retinal vascular beds and reduced diastolic blood pressure compared to placebo.

Role of Nitric Oxide on Papillary Blood Flow and Pressure Natriuresis

Hypertension ◽  
1995 ◽  
Vol 25 (3) ◽  
pp. 408-414 ◽  
Author(s):  
Francisco J. Fenoy ◽  
Paloma Ferrer ◽  
Luis Carbonell ◽  
Miguel García-Salom
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Pressure Natriuresis
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