WATER COMPARTMENTALIZATION IN FETAL ANEMIA

Project: Research project

Description

In acute isovolemic fetal anemia there is an increased blood flow to the
brain and heart with no change in blood pressure or cardiac output. In
contrast, in chronic isovolemic fetal anemia we have found increases in
blood flow to all tissues except the placenta. Despite an increase in
cardiac output, mean arterial pressure falls indicating a major decrease in
systemic vascular resistance. In the proposed studies we plan to examine
some of the mechanisms that determine vascular resistance, cardiac output
and fluid balance in fetal adaptation to chronic anemia. Specifically, we
will test the following hypotheses: (1) The mechanism of the decrease in
vascular resistance is primarily related to the decrease in blood viscosity
hindrance in chronically anemic fetuses in which the viscosity, but not
oxygen content is acutely returned to normal by infusion of methemoglobin
treated red blood cells. Secondarily, we will test the hypothesis that
endothelial derived relaxant factor (EDRF) can account for the remaining
decrease in vascular resistance in individual tissues with chronic anemia.
(2) The increase in cardiac output occurs predominantly by an increase in
stroke volume mediated by ventricular remodelling. By remodelling we mean
an increase in end-diastolic volume and stroke volume as a function of
filling pressure in control and chronically anemic fetuses. (3) As a
result of a decrease in precapillary/postcapillary resistance, capillary
hydrostatic pressure will increase and there will be a increase in a net
capillary filtration and lymph flow. We will measure lymph flow and the
extent of the increase in extravascular fluid by determining the sodium and
inulin volume of distribution. We will use these measurements to further
estimate the forces that determine fluid filtration.
StatusFinished
Effective start/end date2/1/922/28/09

Funding

  • National Institutes of Health: $88,237.00
  • National Institutes of Health: $301,087.00
  • National Institutes of Health: $96,201.00
  • National Institutes of Health
  • National Institutes of Health: $302,000.00
  • National Institutes of Health: $235,802.00
  • National Institutes of Health: $294,903.00
  • National Institutes of Health: $209,119.00
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $241,953.00
  • National Institutes of Health: $250,745.00
  • National Institutes of Health: $286,350.00

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Anemia
Water
Lymph
Fetus
Blood Vessels
Sheep
Cardiac Output
Vascular Resistance
Stroke Volume
Vascular Endothelial Growth Factor A
Growth
Pressure
Nitric Oxide
Ventricular Remodeling
Water-Electrolyte Balance
Viscosity
Adenosine
Aquaporin 1
Parturition
Injections

ASJC

  • Medicine(all)