Nylidrin

This drug is classified as a beta receptor agonist.The β2-adrenergic receptor belongs to the widely expressed 7-transmembrane receptors superfamily, which signals through heterotrimeric G-proteins. They are frequently referred to as G-protein-coupled receptors because they accomplish signal transduction to the interior of the cell by interactions with guanine nucleotide regulatory binding proteins. The receptor-coupled G-proteins work as “molecular switches” which alternate from an inactive guanosine-diphosphate to an active guanosine-triphosphate (GTP) state, which then act to modulate all downstream cell processes. Signaling by various hormones and neurotransmitters, as well as photons and odors, follows the same general pathway, (i.e., by binding of an extracellular ligand to the receptor, which then interacts with the membrane-bound G-protein). This complex, often referred to as the ternary complex, then acts through the activated G-protein to regulate an effector, such as adenylyl cyclase, phospholipase C, or ion channels.

The main effects of Nylidrin may be divided into 3 categories:

Blood vessels

Vascular smooth muscle has β2-adrenoceptors that have a high binding affinity for circulating epinephrine and a lower affinity to norepinephrine released by sympathetic adrenergic nerves. When nylidrin binds to the beta-adrenergic receptors, it prevents the binding of epinephrine, leading to decreased blood vessel contractility as epinephrine is unable to bind.

Heart:

Increased intracellular cAMP by beta-2-agonists inhibits myosin light chain kinase, leading to relaxation These receptors, like the receptors in the heart, are coupled to a Gs-protein, which acts stimulate the formation of cAMP. Although increased cAMP increases cardiac myocyte contraction, in vascular smooth muscle, an increase in cAMP causes smooth muscle relaxation. The reason for this is the fact that cAMP inhibits myosin light chain kinase that is responsible for phosphorylating smooth muscle myosin. Increases in intracellular cAMP caused by β2-agonists inhibit myosin light chain kinase thereby producing less contractile force (i.e., promoting relaxation).

Other tissues

Activation of β2-adrenoceptors in the lungs causes bronchodilation. β2-adrenoceptor activation leads to hepatic glycogenolysis and the pancreatic secretion of glucagon, increasing plasma glucose concentrations. β1-adrenoceptor stimulation in the kidneys promotes the release of renin, stimulating the production of angiotensin II and the subsequent release of aldosterone by the adrenal cortex.