Title :
Determination of hematocrit from mean transit time of red blood cells and plasma in cremaster muscle of the rat
Author :
Cram, L. ; Lipowsky, H.
Author_Institution :
Pennsylvania State Univ., University Park, PA, USA
Abstract :
Indicator dilution methods were used to measure the mean transit time of bolus injections of fluorescently labeled red cells (MTTrbc) and plasma (MTTplasma) containing 5 gms% fluorescent albumin. Following injection of a bolus into the femoral artery contralateral to the cremaster muscle, intensity time curves of the bolus dispersion were obtained within functionally paired arterioles and venules of successive microvascular divisions. The intensity time curves were obtained by digitizing videodensitometric measurements recorded under fluorescence microscopy. The average microvascular hematocrit (Hm) present in the network between these two sites is evaluated assuming that the resident volume of either red cells or plasma is equal to the product of their volumetric flow and respective mean transit times, and the actual discharge hematocrit (Hd) is assumed to be equal to the systemic hematocrit
Keywords :
biological techniques and instruments; blood; cellular transport and dynamics; molecular biophysics; molecular fluorescence; muscle; proteins; average microvascular hematocrit; bolus dispersion; bolus injections; cremaster muscle; femoral artery; fluorescence microscopy; fluorescent albumin; fluorescently labeled red cells; functionally paired arterioles; indicator dilution methods; intensity time curves; mean transit time; plasma; rat; red blood cells; successive microvascular divisions; venules; videodensitometric measurements; volumetric flow; Arteries; Cells (biology); Electron tubes; Fluorescence; Muscles; Plasma measurements; Plasma transport processes; Rats; Red blood cells; Time measurement;
Conference_Titel :
Bioengineering Conference, 1990., Proceedings of the 1990 Sixteenth Annual Northeast
Conference_Location :
State College, PA
DOI :
10.1109/NEBC.1990.66326