Alpha- and beta-adrenoceptors in hypertension. II. Platelet alpha 2- and lymphocyte beta 2-adrenoceptors in children of parents with essential hypertension. A model for the pathogenesis of the genetically determined hypertension.
To study whether changes in alpha- and beta-adrenoceptors in human essential hypertension (EHT) might be genetically determined, we assessed platelet alpha 2- and lymphocyte beta 2-adrenoceptor density in 48 normotensive children of normotensive parents (NT) and in 41 normotensive children with one EHT-parent. Both groups did not differ in age, body weight and height, blood pressure, heart rate, plasma catecholamine levels, plasma renin activity (PRA), and lymphocyte beta 2-adrenoceptor density. Platelet alpha 2-adrenoceptor density, however, was in EHT-children significantly higher than in NT-children. In NT-children, platelet alpha 2-adrenoceptors were significantly, inversely correlated with PRA, indicating that they might mirror renal alpha 2-adrenoceptors which inhibitorily regulate renin release. In contrast, in EHT-children PRA was not at all related to platelet alpha 2-adrenoceptors, suggesting an early (even in the normotensive stage) disturbance of the alpha 2-adrenoceptor-mediated regulation in renin release. From these results and those obtained in the experimental rat models of acquired hypertension, a model for the pathogenesis of the genetically determined hypertension is proposed in which a very early step in the development of hypertension is a genetically determined increase in renal alpha-adrenoceptors that causes enhanced sodium retention. This initiates a chain of events that finally results in increased peripheral vascular resistance and, hence, blood pressure. On the other hand, beta-adrenoceptor changes seem to be secondary phenomena due to the elevation in blood pressure.
Michel
M C
MC
Division of Renal & Hypertensive Diseases, Medizinische Klinik & Poliklinik, Essen, Federal Republic of Germany.
Galal
O
O
Stoermer
J
J
Bock
K D
KD
Brodde
O E
OE
D000293:Adolescent; D001665:Binding Sites; D001792:Blood Platelets / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000235:genetics*; D007223:Infant; D008214:Lymphocytes / Q000032:analysis*; D008297:Male; D011942:Receptors, Adrenergic, alpha / Q000032:analysis*; D011943:Receptors, Adrenergic, beta / Q000032:analysis*; D012083:Renin / Q000097:blood
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D012083:Renin