ISSN:
1432-2013
Keywords:
Rat heart
;
Hemoglobin
;
Coronary blood flow
;
Capillary density
;
Oxygen delivery
;
O2 affinity P50
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The effect of an increase in hemoglobin O2 affinity on myocardial O2 delivery was studied in a blood perfused working rat heart preparation. In a first series of experiments P50 ( $${\text{P}}_{{\text{O}}_{\text{2}} }$$ for which saturation is 50%) was lowered by use of carbon monoxide. The heart was alternatively perfused with the blood sample of P50=32 mm Hg and the blood sample of P50=17 mm Hg. O2 capacity of both samples was kept the same by appropriate hemodilution. In a second serie of experiments change of P50 was obtained by the use of adult human erythrocytes containing hemoglobin creteil with a P50 of 13.6 mm Hg. As P50 decreased from 25 to 10 mm Hg, coronary sinus $${\text{P}}_{{\text{O}}_{\text{2}} }$$ ( $${\text{Pcs}}_{{\text{O}}_{\text{2}} }$$ ) diminished from 26±2 to 18±2 mm Hg (−29±2%), coronary sinus O2 content ( $${\text{Ccs}}_{{\text{O}}_{\text{2}} }$$ ) increased by 15±3%, myocardial oxygen consumption did not change significantly. The percentage of increase of coronary flow was 23±4%. Analysis of these results with a simple mathematical model of O2 delivery suggest that increase in $${\text{Hb}}_{{\text{O}}_{\text{2}} }$$ affinity is corrected by a simultaneous increase in coronary flow and capillary recruitment.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00585904
Permalink
