Human neonatal red cells. Regulatory volume response under anisotonic conditions.
Studies have been carried out in human neonatal red cells (cord blood) to examine the outcome of cellular volume under anisotonic media. When exposed to hypertonicity these cells showed, after an initial shrinkage phase, a volume expansion that reached short of the original volume at 60 minutes. The chloride replacement by nitrate as well as amiloride (in chloride media) inhibited this regulatory volume response. The cellular sodium increase that paralleled the volume expansion was also amiloride-sensitive. We suggest that a Na+/H+ antiport mechanism could mediate the response. Cell volume increase in hypotonic media was not followed by a shrinkage phase.
Serrani
R E
RE
Catedra de Fisiologia, Facultad de Ciencias Médicas, Universidad Nacional de Rosario, Argentina.
Gioia
I A
IA
Corchs
J L
JL
D004911:Erythrocyte Volume / Q000502:physiology*; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D007038:Hypotonic Solutions; D007231:Infant, Newborn / Q000097:blood*; D007552:Isotonic Solutions; D011188:Potassium / Q000097:blood; D012413:Rubidium; D012462:Saline Solution, Hypertonic; D012964:Sodium / Q000097:blood
D007038:Hypotonic Solutions; D007552:Isotonic Solutions; D012462:Saline Solution, Hypertonic; D012964:Sodium; D012413:Rubidium; D011188:Potassium