title: Atenolol enhances growth hormone release to exogenous growth hormone-releasing hormone but fails to alter spontaneous nocturnal growth hormone secretion in boys with constitutional delay of growth.
abstract: We tested the hypothesis that selective beta 1-adrenergic blockade will enhance growth hormone (GH) secretion in boys with constitutional delay of growth in response to both exogenously administered growth hormone-releasing hormone as well as to endogenous GH-releasing hormone pulsations. The study group comprised eight healthy, short, prepubertal boys ranging from 7 2/12 to 15 0/12 yr old with bone ages delayed 15 to 42 months. All had demonstrated GH levels of greater than 10 ng/ml following a pharmacologic or physiologic stimulus. During two consecutive nights, blood samples were withdrawn every 20 min for GH determination between 2000 and 0800 h. Immediately after each 0800 h blood withdrawal, 1 microgram/kg of GH-releasing hormone (1-40)-OH was administered intravenously to each subject and blood was withdrawn every 15 min for an additional 2 h. During the day before the second overnight sampling period each subject received atenolol, 25 mg orally, at 1030 and 1600 h to induce beta-adrenergic blockage. The six subjects in whom beta-adrenergic blockade could be documented had enhanced GH release after GH-releasing hormone administration on the atenolol treatment day both in terms of higher peak GH levels achieved (p less than 0.05) as well as greater total GH secretion (3916 +/- 701 versus 5624 +/- 986 ng/ml.min, p less than 0.01). In contrast, there were no differences in endogenous, unstimulated nocturnal GH pulse characteristics between study and control days.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000293:Adolescent; D001262:Atenolol / Q000494:pharmacology*; D001827:Body Height / Q000187:drug effects; D002648:Child; D002940:Circadian Rhythm; D013006:Growth Hormone / Q000096:biosynthesis* / Q000172:deficiency; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D006801:Humans; D008297:Male; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*
chemical_list: D001262:Atenolol; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone