infants below 2 years of age had a significant lower beta 2-adrenoceptor density ( 588 +/- 63 icyp binding sites/cell ; n = 8 ) when compared with the beta 2-adrenoceptor density in children older than 2 years ( 763 +/- 38 icyp binding sites/cell ; n = 68 ) .
C0021270
infants
C0008059
children