Cardiovascular and renal effects of angiotensin converting enzyme inhibition in man

The aim of the study presented in this thesis was to clarify firstly whether or not pretreatment plasma renin is an important predictor of the blood pressure response to captopril during both acute and chronic treatment and to establish in more detail the haemodynamic profile of actions of this drug in various forms of hypertension. For this purpose the effects of captopril treatment were investigated in patients with a wide range of plasma levels of renin i.e. normotensive anephric patients in whom active renin in plasma was almost zero, patients with essential hypertension with low to normal renin and patients with renovascular hypertension with normal to high renin and finally in normotensive patients with heart failure with renin levels that were often extremely high. A second goal of the present study was to provide some insight into the relation between the degree of inhibition of converting enzyme with captopril and the antihypertensive effect of this drug. Finally, some data were collected on the acute and chronic effects of captopril on renal function in essential and renovascular hypertension. Chapter 2 gives a description of the methods we have used. Chapter 3 deals with the effects of captopril on haemodynamic parameters and body fluid volumes in mild to moderate essential and renovascular hypertension and in severe, so-called drugresistant, hypertension. Chapter 4 presents further data on the haemodynamic effects of captopril in essential and renovascular hypertension as well as in cardiac failure. The results are related to the pretreatment levels of plasma renin. Chapter 5 describes the effect of captopril on blood pressure in nephrectomized patients. In chapter 6 a comparison is made between the acute effects of captopril on blood presure in renovascular and essential hypertension and in anephric normotensive patients. Chapter 7 deals with the measurement of converting enzyme in plasma in patients on captopril. The results of this measurement are related to the blood pressure response to this drug. Chapter 8 describes the effects of captopril on renal function in patients with renovascular hypertension. Chapter 9 describes the renal effects of captopril in patients with essential hypertension. In chapter 10 the conclusions to be drawn from our studies 3.re discussed