Effect of propranolol on growth hormone response to GH releasing hormone (GHRH 1-44) in the dog.
The present study was undertaken to examine whether beta-adrenergic blockade with propranolol might influence and make less variable the growth hormone (GH) response to exogenous GH releasing hormone (GHRH) 1-44 in the dog. On four separate occasions eight healthy beagles, one to two years old, randomly received either propranolol (40 micrograms kg-1 intravenously) or an equivalent volume of saline, 30 minutes before either GHRH 1-44 (1 microgram kg-1 intravenously) or vehicle was injected. After propranolol alone, GH secretion did not differ from saline (area under the curve [AUC]: 649.5 +/- 128.3 v 633.2 +/- 87.7 ng min ml-1, respectively). GHRH alone elicited a significant increase in GH secretion (AUC: 1230.5 +/- 210.5 ng min ml-1) with a peak concentration of 16.7 +/- 4.8 ng ml-1. When GHRH was injected after propranolol the mean peak (59.1 +/- 14.7 ng ml-1) and secretory area (AUC: 2631.0 +/- 474.4 ng min ml-1) were greater than those observed after GHRH alone. However, from a clinical point of view propranolol pretreatment does not modify the great individual variability of the GH response to GHRH.
Regnier
A
A
Ecole Nationale Vétérinaire, Toulouse, France.
Bret
L
L
Morre
M
M
D000818:Animals; D004285:Dogs / Q000378:metabolism*; D005260:Female; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D008297:Male; D010903:Pituitary Gland, Anterior / Q000187:drug effects* / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology*; D011897:Random Allocation
D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D011433:Propranolol