Structure–Activity Relationships All corticosteroids are constructed on the same primary molecular framework, designated as the steroid nucleus (see Fig. 40-1). Changes in molecular structure may result in altered biologic responses…
The central focus of treating acid–base disturbances is the understanding of the biochemistry of the hydrogen ion. Hydrogen ion concentrations in the various body fluid compartments are precisely regulated in…
Drug Resistance Resistance to chemotherapeutic drugs often occurs and has many causes.3 Some chemotherapy agents lead to induction of drug-metabolizing enzymes in the liver, other tissues, or tumor cells, accelerating…
The effects of cardiac antiarrhythmic drugs on the action potential and effective refractory period of the cardiac action potential determine the clinical effect of these drugs. Drugs that primarily block…
It is generally believed that twitch depression results from block of postsynaptic nicotinic acetylcholine receptors, whereas tetanic or TOF fade results from block of presynaptic nicotinic acetylcholine receptors.10,11 Blockade of…
Body fluids can be divided into intracellular and extracellular fluid, depending on their location relative to the cell membrane (see Fig. 1-1).1 Approximately two-thirds of the total body fluid in…
Maternal Physiology Physiologic Changes during Pregnancy and Delivery During pregnancy and the peripartum period, substantial changes in maternal anatomy and physiology occur secondary to changes in hormone activity, increased maternal…
Without sufficient insulin, transport of glucose across certain cell membranes slows markedly to cause hyperglycemia. The formation of glucose from protein accounts for the discovery that glucose in urine may…
Short-acting β2 agonists bind to the β2-adrenergic receptor located on the plasma membrane of smooth muscle cells, epithelial, endothelial, and many other types of airway cells.11 This causes a stimulatory…
