Once-daily dihydropyridine calcium channel blockers appeared to lower blood pressure by a relatively constant amount throughout the 24-hour dosing interval .
Six dihydropyridine calcium channel blockers studied in this review lowered blood pressure by a relatively similar amount each hour over the course of 24 hours .
BACKGROUND Calcium channel blockers are a heterogeneous class of drugs , including dihydropyridine and non-dihydropyridine subgroups , commonly used in the treatment of hypertension .
A systematic review of the 24-hour time course of the blood pressure-lowering effect has not been published .
OBJECTIVES To assess how much variation there is in hourly systolic and diastolic blood pressure lowering by dihydropyridine calcium channel blockers over a 24-hour period in people with hypertension aged 18 years or over , with baseline systolic blood pressure of at least 140 mmHg or diastolic blood pressure of at least 90 mmHg , or both .
Reduced plasma cyclic GMP but normal renal responses to atrial natriuretic factor in pre-hypertension.
The amount of , and response of the kidneys to , endogenous natriuretic factor(s ) could be important in the pathogenesis of essential hypertension . Search ing for possible disturbance(s ) related to atrial natriuretic factor ( ANF ) and its second messenger , cyclic guanosine monophosphate ( c-GMP ) , we assessed plasma immunoreactive ( ir ) ANF and c-GMP , effective renal plasma flow ( ERPF ) , glomerular filtration rate ( GFR ) , urinary c-GMP , absolute and fractional ( FE ) excretions of sodium ( Na ) and chloride ( Cl ) before and during infusions of low ANF doses or vehicle ( V ) in 7 normotensive sons of essential hypertensive parents ( SEH ) compared with 7 sons of normotensive parents ( SN ) . Each subject was infused at 2-week intervals in a single-blind r and omized sequence with 4 different solutions : V only or ANF 0.004 , 0.008 and 0.016 microgram/kg/min , infused over 90 min . Plasma irANF was lower in SEH than in SN ( p < 0.001 ) during vehicle infusion . Basal plasma c-GMP levels were , on all 4 different study days lower ( p < 0.05 to < 0.01 ) in SEH in SN . Response of plasma c-GMP to infused ANF was also slightly decreased in SEH ( p < 0.05 to < 0.01 ) . BP , ERPF and GFR did not differ between SEH and SN and were unchanged during the 4 infusions . Urinary c-GMP excretion , FENa and FECl increased dose-dependently during ANF ( p < 0.05 to < 0.0001 ) but not V infusions . These findings indicate that at the stage of pre-hypertension a disturbance in the ANF-c-GMP regulatory pathway may occur , which is expressed primarily at the circulatory rather than the renal excretory level
Once-daily dihydropyridine calcium channel blockers appeared to lower blood pressure by a relatively constant amount throughout the 24-hour dosing interval .
Six dihydropyridine calcium channel blockers studied in this review lowered blood pressure by a relatively similar amount each hour over the course of 24 hours .
BACKGROUND Calcium channel blockers are a heterogeneous class of drugs , including dihydropyridine and non-dihydropyridine subgroups , commonly used in the treatment of hypertension .
A systematic review of the 24-hour time course of the blood pressure-lowering effect has not been published .
OBJECTIVES To assess how much variation there is in hourly systolic and diastolic blood pressure lowering by dihydropyridine calcium channel blockers over a 24-hour period in people with hypertension aged 18 years or over , with baseline systolic blood pressure of at least 140 mmHg or diastolic blood pressure of at least 90 mmHg , or both .