Imbalance between alpha- and beta-adrenoceptor binding sites in marker cells in cystic fibrosis.
We investigated the characteristics of adrenergic receptor binding in peripheral blood cells from 6 patients with cystic fibrosis(CF) and 20 age-matched control subjects. There was a tendency (p = 0.08) towards a difference in dissociation constant of specific (125I)-hydroxybenzylpindolol (IHYP) binding in polymorphonuclear leukocytes (beta 2-adrenoceptor) from CF patients (113.0 pM +/- 32.8, SD) and controls (84.3 pM +/- 30.4, SD). We found no consistent differences in maximum binding capacity (Bmax) for either (3H)-yohimbine(YOH) binding in platelets (alpha 2-adrenoceptor) or IHYP bindings between the two groups. The ratio of YOH versus IHYP binding sites was significantly greater in CF patients (1.51 +/- 0.48) than in controls (1.07 +/- 0.34) (P less than 0.05). This might provide a possible explanation for the increased vasoconstriction and decreased heart rate response to adrenergic agonists in CF patients.
D001792:Blood Platelets / Q000378:metabolism; D003550:Cystic Fibrosis / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D010869:Pindolol / Q000031:analogs & derivatives; D011506:Proteins / Q000378:metabolism; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D015016:Yohimbine / Q000378:metabolism
D011506:Proteins; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D015016:Yohimbine; C012357:hydroxybenzylpindolol; D010869:Pindolol