Compounds of the Formula ##STR1## wherein: K is N or N.fwdarw.O; Q is CH.sub.2 or O; T is ##STR2## or R.sub.3 O--CH.sub.2 ; X is a straight or branched chain alkylene, cycloalkylene or cycloalkenylene group, each of which is optionally substituted by at least one CH.sub.3, CH.sub.3 CH.sub.2, Cl, F, CF.sub.3 or CH.sub.3 O; Y is NR.sub.4, O or S; a=0 or 1; Z is of the formula ##STR3## Z.sub.1 is N, CR.sub.5, (CH).sub.m --CR.sub.5 or (CH).sub.m --N, m being 1 or 2; Z.sub.2 is N, NR.sub.6, O or S, n being 0 or 1; R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are independently H, alkyl, aryl or heterocyclyl; R.sub.a and R.sub.b are independently H, OH, alkyl, hydroxyalkyl, alkyl mercaptyl, thioalkyl, alkoxy, alkyoxyalkyl, amino, alkyl amino, carboxyl, acyl, halogen, carbamoyl, alkyl carbamoyl, aryl or heterocyclyl; and R' and R" are independently hydrogen, alkyl, aralkyl, carbamoyl, alkyl carbamoyl, dialkylcarbamoyl, acyl, alkoxycarbonyl aralkoxycarbonyl, aryloxycarbonyl, or R' and R" together may form ##STR4## where R.sub.c is hydrogen or alkyl, ##STR5## where R.sub.d and R.sub.e are independently hydrogen, alkyl, or together with the carbon atom to which they are attached may form a 1,1-cycloalkyl group; provided that when X is straight chain alkylene and Q is oxygen, then Z represents a heterocyclyl including at least two heteroatoms, which are adenosine agonists useful as antihypertensive, cardioprotective, antiischemic, and antilipolytic agents, pharmaceutical compositions including such compounds, and their use in treating hypertension, myocardial ischemia, ameliorating ischemic injury and myocardial infarct size consequent to myocardial ischemia, hyperlipidemia and hypercholesterolemia are claimed.