Effects of barium-induced cardiac contraction on large- and small-vessel intramyocardial blood volume.

We have measured the effects of barium-induced cardiac contraction on the intramyocardial blood volume content of all vessels and have independently measured the blood volume content of vessels with a diameter greater than 100 microns in rat myocardium. Measurements of total intramyocardial blood volume were made by using [125I]albumin as a plasma marker and technetium-99m as a red blood cell marker. In one group of rats (n = 8), diastolic arrest was induced by an intravenous injection of KCl; in a second group (n = 8), systolic arrest was induced by an intravenous injection of BaCl2. In both groups, the hearts were frozen in situ immediately after heart arrest while aortic pressure was decaying from its former physiological level. The left ventricular free wall was sectioned transmurally in a cryomicrotome, and the blood volume within each tissue sample was calculated from its radioactivity. The volume of blood in vessels larger than 100 microns was independently estimated from the exposed cross-sectional area of these vessels in photographs of the frozen tissue taken during tissue sectioning in the cryomicrotome. Total intramyocardial blood volume was found to decrease by about 42% from 8.6 +/- 1.3 ml/100 g (mean +/- SEM) in the KCl group to 5.0 +/- 0.7 ml/100 g in the BaCl2 group (p less than 0.01). Total volume was greater in the epicardial than in the endocardial layers of both groups (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

[1]  C. Bloor,et al.  Cardiac vasculature and flow during pressure-overload hypertrophy. , 1986, The American journal of physiology.

[2]  A Tedgui,et al.  Phasic regional myocardial inflow and outflow: comparison of theory and experiments. , 1990, The American journal of physiology.

[3]  P. Anversa,et al.  Absolute morphometric study of myocardial hypertrophy in experimental hypertension. II. Ultrastructure of myocytes and interstitium. , 1978, Laboratory investigation; a journal of technical methods and pathology.

[4]  G. Arturson,et al.  Studies on Heart Lymph , 1964 .

[5]  J Grayson,et al.  The functional morphology of the coronary microcirculation in the dog. , 1974, Microvascular research.

[6]  A. Clark,et al.  Capture of spatially homogeneous chemical reactions in tissue by freezing. , 1983, Biophysical journal.

[7]  R. Bellamy,et al.  Diastolic Coronary Artery Pressure‐Flow Relations in the Dog , 1978, Circulation research.

[8]  A. Liedtke,et al.  Small Coronary Vessel Pressure and Diameter in an Intact Beating Rabbit Heart Using Fixed‐Position and Free‐Motion Techniques , 1981, Circulation research.

[9]  R. Mates,et al.  Coronary Pressure‐Flow Relationships: Controversial Issues and Probable Implications , 1985, Circulation research.

[10]  J B Bassingthwaighte,et al.  Microvasculature of the dog left ventricular myocardium. , 1974, Microvascular research.

[11]  J. Spaan.  Coronary Diastolic Pressure‐Flow Relation and Zero Flow Pressure Explained on the Basis of Intramyocardial Compliance , 1985, Circulation research.

[12]  G. Arturson,et al.  STUDIES ON HEART LYMPH. I. KINETICS OF 131-I-ALBUMIN IN DOG HEART-LUNG PREPARATIONS. , 1964, Acta physiologica Scandinavica.

[13]  K. Rakušan.  Vascular capacity and hematocrit in experimental cardiomegaly due to aortic constriction in rats. , 1971, Canadian journal of physiology and pharmacology.

[14]  M. Noble,et al.  Intramyocardial blood volume change in first moments of cardiac arrest in anesthetized goats. , 1987, The American journal of physiology.

[15]  C. Honig,et al.  NUMBER AND DISTRIBUTION OF CAPILLARIES AS DETERMINANTS OF MYOCARDIAL OXYGEN TENSION. , 1964, The American journal of physiology.

[16]  D. Hyde,et al.  Morphometry of the coronary microvasculature of the canine left ventricle. , 1986, The American journal of anatomy.

[17]  A. Gerdes,et al.  Differences in regional capillary distribution and myocyte sizes in normal and hypertrophic rat hearts. , 1979, The American journal of anatomy.

[18]  H. Weiss,et al.  Microvascular morphometry and perfusion in renal hypertension-induced cardiac hypertrophy. , 1988, The American journal of physiology.

[19]  W. T. Porter,et al.  THE INFLUENCE OF THE HEART-BEAT ON THE FLOW OF BLOOD THROUGH THE WALLS OF THE HEART , 1898 .

[20]  J. Michel,et al.  Phasic coronary flow during aorto-caval fistula unclamping in dog. , 1988, The Journal of surgical research.

[21]  A. Gerdes,et al.  Morphometric study of endomyocardium and epimyocardium of the left ventricle in adult dogs. , 1980, The American journal of anatomy.

[22]  J M Fauvel,et al.  Microcirculation in the Ventricle of the Dog and Turtle , 1974, Circulation research.

[23]  F. Vetterlein,et al.  Capillary density in rat myocardium during timed plasma staining. , 1982, The American journal of physiology.

[24]  G. J. Crystal,et al.  Small vessel and total coronary blood volume during intracoronary adenosine. , 1981, The American journal of physiology.

[25]  J. Downey,et al.  Barium contracture: a model for systole. , 1980, The American journal of physiology.

[26]  H. Weiss,et al.  Morphometric study of the total and perfused arteriolar and capillary network of the rabbit left ventricle. , 1985, Cardiovascular research.

[27]  R. Bellamy,et al.  Cessation of arterial and venous flow at a finite driving pressure in porcine coronary circulation. , 1984, The American journal of physiology.

[28]  P. Salisbury,et al.  Physiological factors influencing coronary blood volume in isolated dog hearts. , 1961, The American journal of physiology.

[29]  S. Haunsø,et al.  Regional blood flow, microvascular blood content and tissue haematocrit in canine myocardium. , 1982, Cardiovascular research.

[30]  W. Kubler,et al.  Pressure Measurements in the Terminal Vascular Bed of the Epimyocardium of Rats and Cats , 1981, Circulation research.