Drug Name Lotensin

In principle, lowering of either cardiac output or peripheral resistance may decrease blood pressure (cf. p. 306, 314, blood pressure determinants). The available drugs influence one or both of these determinants. The therapeutic utility of antihypertensives is determined by their efficacy and tolerability.
In this manner, they maintain the transmembrane gradients for K+ and Na+, the negative resting membrane potential, and the normal electrical excitability of the cell membrane. When part of the enzyme is occupied and inhibited by CG, the unoccupied remainder can increase its level of activity and maintain Na+ and K+ transport.

 

Tetrahydrofolic acid (THF) is required for the synthesis of both purine bases and thymidine. Formation of THF from folic acid involves dihydrofolate reductase. The folate analogues aminopterin and methotrexate (amethopterin) inhibit enzyme activity as false substrates. As cellular stores of THF are depleted, synthesis of DNA and RNA building blocks ceases.
Released ACh is rapidly hydrolyzed and inactivated by a specific acetylcholinesterase, present on pre- and postjunctional membranes, or by a less specific serum cholinesterase (butyryl cholinesterase), a soluble enzyme present in serum and interstitial fluid.