In three experiments involving young adult males, beta‐adrenergic influences on heart rate and carotid dP/dt were evaluated as a function of the degree of individual control over stressful events. Beta‐adrenergic effects were more pronounced under conditions in which the subjects were either led to believe they had control or where some control was actually provided, i.e., a shock avoidance task. Beta‐adrenergic influences were either minimal or rapidly dissipated under conditions where no control was possible, i.e., the cold pressor, a pornographic film, inescapable shocks, or conditions which provided ready mastery of the task. Where beta‐adrenergic effects were maximal, systolic blood pressure was more appreciably elevated while diastolic blood pressure was less elevated than when beta‐adrenergic effects were minimal. A pharmacological blocking agent (propranolol) was used in one experiment to specify the extent the various cardiovascular changes were influenced by beta‐adrenergic activity. The results are discussed with respect to issues concerning stimulus parameters, blood pressure control mechanisms, individual differences in cardiovascular reactivity, and some methodological problems of the current study.

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The effects of two behavioral tasks, treadmill exercise and shock avoidance, on renal and cardiovascular function were examined in dogs during intravenous infusion of isotonic saline. Urine was collected with a bladder catheter. Control experiments established steady base lines of urine flow (V), sodium excretion (UNaV), glomerular filtration rate (GFR), free water clearance (CH2O), heart rate (HR), and arterial pressure (Pa). Exercise led to increased V, UNaV, GFR, HR, and Pa with no change in CH2O. Avoidance caused decreases in V and UNaV, increases in HR and Pa but no change in either GFR or CH2O. The hematocrit increased significantly during both tasks. Exercise and avoidance led to opposite urinary changes even when HR accelerations were identical. The natriuretic effect of exercise was the consequence of an increased filtered load, while the antinatriuretic effect of shock avoidance was apparently due to an increased rate of tubular reabsorption of filtrate. The results show that exercise and shock avoidance, while eliciting similar cardiovascular changes, lead to opposite adjustments in urine and sodium output.

• The goal of improving access to quality medicines in East Africa has been addressed by the East African Community (EAC) Medicines Regulatory Harmonization (MRH) initiative, which is working to simplify the process of registering medicines and increase the speed at which registration applications are reviewed while ensuring that only highquality medicines are approved. • This article was written by a group of authors with varied expertise in global regulatory affairs but no involvement to date in the EAC MRH initiative. The authors were asked to provide an independent perspective on the initiative's work since its launch in 2012, as well as its plans for the future.