79837
document
Changes in heart rate and forearm blood flow following intravenous boluses of isoprenaline in the presence of practolol and propranolol . 1 Increases in heart rate and forearm blood flow following graded intravenous bolus injections of isoprenaline sulphate , were measured in a double-blind randomised study of six subjects who received either placebo , practolol 50 mg , practolol 200 mg , propranolol 10 mg or propranolol 40 mg. 2 Dose related increases in forearm blood flow were produced by the graded boluses of isoprenaline sulphate . 3 Practolol 50 mg attenuated the heart rate response to isoprenaline but did not significantly affect the changes in forearm blood flow . Practolol 200 mg further attenuated the heart rate responses but also decreased the forearm blood flow responses . 4 Propranolol 10 mg and propranolol 40 mg significantly attenuated both the heart rate and forearm blood flow responses . The effect on forearm blood flow tended to be greater than the effect on heart rate . 5 Practolol 200 mg had the same effect on heart rate responses as propranolol 10 mg but a significantly smaller effect on the forearm blood flow responses . 6 The measurement of forearm blood flow following intravenous bolus injections of isoprenaline provides useful information about the beta 2-adrenoceptor antagonism of propranolol and practolol . However , application of the technique may be limited by the magnitude of the heart rate response and by the short-lived nature of the increase in forearm blood flow .
79838
Intervention_Pharmacological
isoprenaline
79839
Intervention_Pharmacological
isoprenaline sulphate
79840
Intervention_Control
placebo
79841
Intervention_Pharmacological
practolol
79842
Intervention_Pharmacological
practolol
79843
Intervention_Pharmacological
propranolol
79844
Intervention_Pharmacological
propranolol
79845
Intervention_Pharmacological
isoprenaline sulphate
79846
Intervention_Pharmacological
Practolol
79847
Intervention_Pharmacological
Practolol
79848
Intervention_Pharmacological
Propranolol
79849
Intervention_Pharmacological
Practolol
79850
Intervention_Pharmacological
propranolol
79851
Intervention_Pharmacological
propranolol
79852
Intervention_Pharmacological
practolol
79853
Outcome_Physical
heart rate
79854
Outcome_Physical
forearm blood flow
79855
Outcome_Physical
heart rate
79856
Outcome_Physical
forearm blood flow
79857
Outcome_Physical
forearm blood flow
79858
Outcome_Physical
heart rate response
79859
Outcome_Physical
forearm blood flow
79860
Outcome_Physical
heart rate responses
79861
Outcome_Physical
forearm blood flow responses
79862
Outcome_Physical
heart rate
79863
Outcome_Mental
and
79864
Outcome_Physical
forearm blood flow responses
79865
Outcome_Physical
forearm blood flow
79866
Outcome_Physical
heart rate
79867
Outcome_Physical
heart rate responses
79868
Outcome_Physical
forearm blood flow responses
79869
Outcome_Physical
forearm blood flow
79870
Outcome_Physical
heart rate
79871
Outcome_Physical
forearm blood flow
79872
Participant_Sample-size
six