AJP - Heart and Circulatory Physiology, Vol 233, Issue 1 1-19, Copyright © 1977 by American Physiological Society
Fibrinogen synthesis stimulation by prostaglandin E1 and some other vasodilators
T. H. Carlson, D. C. Fradl, B. D. Leonard, S. H. Wentland and E. B. Reeve
Three-hour constant-rate intravenous infusion into rabbits of 1-3 mg
prostaglandin E1 (PGE1) per kilogram markedly increased plasma fibrinogen
24 h later. 131I-labeled fibrinogen and model studies showed increased
synthesis underlay this. Similar PGE1 doses lowered systolic blood
pressure. Maintaining systolic blood pressure by infusing noradrenaline
with the PGE1 did not alter plasma fibrinogen response to PGE1; plasma
fibrinogen was unchanged by noradrenaline infusion. Regression equations
relating plasma fibrinogen increment to PGE1 dose, plasma fibrinogen
increment to dose and systolic blood pressure change, and systolic blood
pressure change to dose are given as well as the constants relating plasma
fibrinogen increment to dose using the Michaelis-Menten equation. Infusions
of cyclic AMP, dibutyryl cyclic AMP, and cyclic GMP intravenously led to
only small plasma fibrinogen increases. Daily intravenous infusions of PGE1
led to loss of both plasma fibrinogen and systolic blood pressure responses
in two animals; a third animal showed only loss of the former and a fourth
only loss of the latter response. PGE1 slightly enhanced the small plasma
fibrinogen increase following intravenous bradykinin. Approximate arterial
blood PGE1 concentrations resulting from the intravenous infusion of 1 mg
mg PGE1 kg-1 3 h-1 are calculated. These are compared with measured values.
