1adrenergiline

1-Adrenergic receptors, often abbreviated as 1AR or α1-AR, are a class of G protein-coupled receptors that are part of the adrenergic receptor family. They are the primary targets for the neurotransmitter norepinephrine and the hormone epinephrine, commonly known as adrenaline. These receptors are found on the surface of various cells throughout the body, particularly in smooth muscle tissue, the heart, and the central nervous system.

Activation of 1-adrenergic receptors by agonists like norepinephrine leads to a cascade of intracellular events. Specifically, they are coupled to Gq proteins, which in turn activate phospholipase C. This enzyme hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol trisphosphate (IP3) and diacylglycerol (DAG). IP3 triggers the release of calcium ions from intracellular stores, while DAG activates protein kinase C. The increase in intracellular calcium is a key mediator of many downstream effects.

The physiological effects of 1-adrenergic receptor activation are diverse. In vascular smooth muscle, it causes vasoconstriction, leading to an increase in blood pressure. In the heart, it can enhance contractility. In the central nervous system, 1-adrenergic receptors are involved in regulating various functions including alertness, mood, and cognition. Due to their widespread distribution and significant physiological roles, 1-adrenergic receptors are important targets for numerous pharmacological agents used to treat conditions such as hypertension, benign prostatic hyperplasia, and nasal congestion.