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Mixing of cells, plasma and dye T-1824 in the cardiovascular system of barbitalized dogs
SELECTED
Miller,
A Re-evaluation A. T.: (Nov.), 1947.
of the
033
ABSTRACTS
T-1824
Mixing
Curve.
Am.
J. Physiol.
151:234
The true disappearance slope of the Evans blue dye from plasma is preceded by mixing of the dye in the plasma. This may be divided into a rapid phase (Phase I), interpreted as demonstrating mixing of freely circulating plasma, and into a slower phase (Phase II) reflecting diffusion of dye into noncirculating plasma. In dogs, the first phase appears to be completed in four to six minutes, the second in thirty to fifty minutes. Extrapolation of Phase II of the mixing curve permits calculation of circulating plasma, while extrapolation of the truedisappearancecurve provides an index of total plasma volume. In 105 experiments on twenty-four dogs, the average circulating plasma volume was 86 per cent of the total plasma volume. Cruickshank represents the
and Whitfield’s conclusions that the extrapolation true plasma volume are again challenged.
of Phase
I of the mixing
curve HECHT.
White, and
H. L., Heinbecker, Oxygen Consumption
P.,
and Rolf, in Dogs.
D.: Am.
Endocrine J. Physiol.
Influences on Cardiac 151:239 (Dec.), 1947.
Output
Thyroidectomy and hypophysectomy produce prompt and permanent falls in oxygen consumption and in cardiac output in normal dogs as measured by the Fick principle. Administration of anterior pituitary hormone (Preloban) increases oxygen consumption and restores cardiac output in the hypophysectomized animal and also, to some extent, in the thyroidectomized animal. Preloban increases cardiac output in the normal dog. Denervation of the neurohypophysis does not alter cardiac output and oxygen consumption. These findings parallel previously observed changes in renal blood flow produced by the same procedures. It is postulated that the anterior lobe of the pituitary gland produces a substance which brings about increase in oxygen consumption, in cardiac output, and in renal flow. The observed effects cannot be explained hy the action of thyrotropic or adrenocorticotropic hormones. HECHT.
Lawson, H. C., Overbey, D. ‘I., Moore, and Dye T-1824 in the Cardiovascular 151:282 (Dec.), 1947.
J. C., and Shadle, 0. W.: System of Barbitalized
Mixing Dogs.
of Cells, Plasma Am. J. Physiol.
The circulatory mixing of cells, plasma, and dye solutions was studied in barbitalized and splenectomized dogs. It appears that complete mixing is accomplished in from three to five minutes when mixing times are determined by arterial hematocrit determinations and optical densities of dyed plasma. Continued rapid disappearance of injected dye beyond the first five minutes is ascribed to escape of dye from the vascular compartment. HECHT.
Overbey, 1). T., Moore, of Dye T-1824 From
J. C., Shadle, 0. W. and Lawson, Arterial Blood. Am. J. Physiol.
Full logarithmic plotting of dye disappearance dye concentration and time that is expressed Ct =
H. C.: 151:290
Rate (Dec.),
of Disappearance 1947.
curves demonstrates a relationship Ci where C is the dye concentration
between at time
-5 1, Ci is the concentration at one minute; r, the time of injection in minutes; and p,. a fractional power (0.0554). A truly exponential rate of dye disappearance is achieved only after two to four hours and three phases of dye disappearance are recognized: an initial rapid disappearance phase (one hour), an intermediate phase (one to three hours), and finally after three hours, a truly exponential phase. Any injection of dye into a previously dye-injected animal must pass through all three phases. A first and a second injection of dye behave identically when allowance is made for the changing rate of disappearance in time. (This is at variance with the reports of Cruickshank and Whitfield.)
Miller,
A Re-evaluation A. T.: (Nov.), 1947.
of the
033
ABSTRACTS
T-1824
Mixing
Curve.
Am.
J. Physiol.
151:234
The true disappearance slope of the Evans blue dye from plasma is preceded by mixing of the dye in the plasma. This may be divided into a rapid phase (Phase I), interpreted as demonstrating mixing of freely circulating plasma, and into a slower phase (Phase II) reflecting diffusion of dye into noncirculating plasma. In dogs, the first phase appears to be completed in four to six minutes, the second in thirty to fifty minutes. Extrapolation of Phase II of the mixing curve permits calculation of circulating plasma, while extrapolation of the truedisappearancecurve provides an index of total plasma volume. In 105 experiments on twenty-four dogs, the average circulating plasma volume was 86 per cent of the total plasma volume. Cruickshank represents the
and Whitfield’s conclusions that the extrapolation true plasma volume are again challenged.
of Phase
I of the mixing
curve HECHT.
White, and
H. L., Heinbecker, Oxygen Consumption
P.,
and Rolf, in Dogs.
D.: Am.
Endocrine J. Physiol.
Influences on Cardiac 151:239 (Dec.), 1947.
Output
Thyroidectomy and hypophysectomy produce prompt and permanent falls in oxygen consumption and in cardiac output in normal dogs as measured by the Fick principle. Administration of anterior pituitary hormone (Preloban) increases oxygen consumption and restores cardiac output in the hypophysectomized animal and also, to some extent, in the thyroidectomized animal. Preloban increases cardiac output in the normal dog. Denervation of the neurohypophysis does not alter cardiac output and oxygen consumption. These findings parallel previously observed changes in renal blood flow produced by the same procedures. It is postulated that the anterior lobe of the pituitary gland produces a substance which brings about increase in oxygen consumption, in cardiac output, and in renal flow. The observed effects cannot be explained hy the action of thyrotropic or adrenocorticotropic hormones. HECHT.
Lawson, H. C., Overbey, D. ‘I., Moore, and Dye T-1824 in the Cardiovascular 151:282 (Dec.), 1947.
J. C., and Shadle, 0. W.: System of Barbitalized
Mixing Dogs.
of Cells, Plasma Am. J. Physiol.
The circulatory mixing of cells, plasma, and dye solutions was studied in barbitalized and splenectomized dogs. It appears that complete mixing is accomplished in from three to five minutes when mixing times are determined by arterial hematocrit determinations and optical densities of dyed plasma. Continued rapid disappearance of injected dye beyond the first five minutes is ascribed to escape of dye from the vascular compartment. HECHT.
Overbey, 1). T., Moore, of Dye T-1824 From
J. C., Shadle, 0. W. and Lawson, Arterial Blood. Am. J. Physiol.
Full logarithmic plotting of dye disappearance dye concentration and time that is expressed Ct =
H. C.: 151:290
Rate (Dec.),
of Disappearance 1947.
curves demonstrates a relationship Ci where C is the dye concentration
between at time
-5 1, Ci is the concentration at one minute; r, the time of injection in minutes; and p,. a fractional power (0.0554). A truly exponential rate of dye disappearance is achieved only after two to four hours and three phases of dye disappearance are recognized: an initial rapid disappearance phase (one hour), an intermediate phase (one to three hours), and finally after three hours, a truly exponential phase. Any injection of dye into a previously dye-injected animal must pass through all three phases. A first and a second injection of dye behave identically when allowance is made for the changing rate of disappearance in time. (This is at variance with the reports of Cruickshank and Whitfield.)