Factors influencing the acid-base changes in the air-pouch exudate following carrageenan induced inflammation in rats.
The interactions between the acid-base variables that contribute to exudate acidosis were studied in the subcutaneous air-pouch after carrageenan injection in rats. We studied the concurrent changes of exudate gases (PCO2 and PO2), main ions ([Na+], [K+], [Ca2+], [Mg2+], [Cl-] and [Lac-]), inorganic phosphate (P(i)) and albumin in acutely inflamed rats (4, 8, 12, 24 and 48 h of inflammation). A notable hypercapnia was found in the exudate after only 8 h (exudate PCO2 = 64.3 +/- 2.9 mm Hg) but this hypercapnia decreased after 48 h (32.9 +/- 12.7 mm Hg), coincident with the greatest increase in exudate cells. With respect to the metabolic acid-base variables, the most important changes found were a parallel decrease in the strong ion difference ([SID]) and exudate pH, as well as increases in the exudate weak acid buffers ([ATOT]) due to albumin and inorganic phosphate (P(i)) increases. However, after 12 h, the exudate acidosis was stable at around pH 7. A similar acid pH was obtained after 24 h of inflammation when the carrageenan solution injected was previously adjusted to a physiological pH (7.4). This pH, analogous to that of the exudate, was the result of compensation by the acid-base independent variables, a fact which suggests that acid pH may be a beneficial condition for cells taking part in inflammatory processes.
Alfaro
V
V
Department of Physiology, University of Barcelona, Spain.
Ródenas
J
J
Pesquero
J
J
Mitjavila
M T
MT
Palacios
L
L
Carbonell
T
T
D000136:Acid-Base Equilibrium / Q000502:physiology*; D000418:Albumins / Q000378:metabolism; D000818:Animals; D002021:Buffers; D002351:Carrageenan; D004487:Edema / Q000139:chemically induced / Q000378:metabolism*; D005122:Exudates and Transudates / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006935:Hypercapnia / Q000378:metabolism; D008297:Male; D010710:Phosphates / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D000418:Albumins; D002021:Buffers; D010710:Phosphates; D011506:Proteins; D002351:Carrageenan