title: Nifedipine does not impair the hormonal responses to graded exercise in healthy subjects.
abstract: The aim of this study was to assess whether the potent calcium antagonist nifedipine was capable of modifying the hormonal response to graded exercise in 7 healthy young men. After fasting overnight, each subject came to the laboratory on 2 consecutive mornings. On one day he was given 10 mg of nifedipine sublingually and on the other an identical placebo capsule; the order was randomised in a double-blind fashion over the 2 days. Thereafter each subject performed 2 successive short treadmill runs, equivalent to 60 and 100%, respectively, of maximal aerobic power. While significantly blunting the rise in mean systolic blood pressure and inducing a greater fall in diastolic blood pressure during and after exercise compared with the placebo, nifedipine did not impair the brisk response to pituitary-adrenal hormones (ACTH, cortisol and total catecholamines). Nifedipine also did not modify the effects of short-term exercise in raising mean plasma glucose levels, stimulating pancreatic glucagon secretion and producing a delayed increase in plasma insulin concentrations. Nor did the drug blunt the significant rise of growth hormone and prolactin levels occurring during and after the treadmill run. It was concluded that, apart from inducing significant changes in blood pressure, a single dose of nifedipine does not appear to suppress the counterregulatory hormonal responses to short-term physical activity in healthy men.
authors.forename: B I
authors.initials: BI
authors.lastname: Joffe
authors.forename: R
authors.initials: R
authors.lastname: Shires
authors.forename: J M
authors.initials: JM
authors.lastname: Lamprey
authors.forename: W J
authors.initials: WJ
authors.lastname: Kalk
authors.forename: A
authors.initials: A
authors.lastname: Botha
authors.forename: B
authors.initials: B
authors.lastname: Haitas
authors.forename: H C
authors.initials: HC
authors.lastname: Seftel
mesh_terms: D000305:Adrenal Cortex Hormones / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D002395:Catecholamines / Q000378:metabolism; D004311:Double-Blind Method; D013006:Growth Hormone / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000494:pharmacology*; D005082:Physical Exertion; D010907:Pituitary Hormones / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism; D011674:Pulse / Q000187:drug effects; D011897:Random Allocation; D013997:Time Factors
chemical_list: D000305:Adrenal Cortex Hormones; D001786:Blood Glucose; D002395:Catecholamines; D010907:Pituitary Hormones; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D013006:Growth Hormone; D009543:Nifedipine; D006854:Hydrocortisone