Direct effects of propofol on myocardial and vascular tissue from mature and immature rats.
OBJECTIVE
To determine the effect of age on the direct myocardial and vascular effects of propofol in rats.


METHODS
Randomized, prospective with repeated measures.


METHODS
University research laboratory.


METHODS
Myocardial and aortic tissue from 12 immature (4-week-old) and 12 mature (16-week-old) male Sprague-Dawley rats.


METHODS
Change in force of contraction was measured in isolated myocardial strips or in isolated descending thoracic aorta rings during exposure to propofol or intralipid.


RESULTS
Propofol produced a dose-dependent decrease in vascular tone (p < 0.05). This effect was similar for intralipid. Propofol was more potent in the younger animals (EC(50), 5.3 microg/mL [confidence interval, 2.5 to 11.1] for 4-week-old and 26.6 microg/mL [confidence interval, 6.8 to 103.7] for 16-week-old rats; p < 0.05). In contrast, propofol produced a dose-dependent decrease in contractility (p = 0.001), whereas intralipid produced no decrease in contractility.


CONCLUSIONS
Although propofol does produce a dose-dependent decrease in contractility, this effect is similar at different ages. Propofol produces more direct vascular relaxation in the immature tissue. Propofol's direct cardiovascular effect and its indirect cardiovascular effects should be considered in the young and old, especially when cardiovascular reserve is limited.
Ririe
D G
DG
Department of Anesthesiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1009, USA. dririe@wfubmc.edu
Lundell
J C
JC
Neville
M J
MJ
D000375:Aging / Q000502:physiology*; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000502:physiology; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D005217:Fat Emulsions, Intravenous / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D015742:Propofol / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology
D018686:Anesthetics, Intravenous; D005217:Fat Emulsions, Intravenous; D014665:Vasodilator Agents; D015742:Propofol