transporters

Cholesterol is the primary sterol in mammals, accounting for approximately 20–25% of the plasma membrane structure. It plays a key role in regulating membrane fluidity, permeability, and protein function. As an endogenous agonist of estrogen-related receptor α (ERRα), cholesterol is widely involved in metabolic regulation and serves as a precursor for the synthesis of hormones and bile acids. It is commonly used in experimental models of hyperlipidemia.

L-Arginine hydrochloride serve as substrates and nitrogen donors for endothelial nitric oxide synthase (eNOS) to produce nitric oxide (NO). They are transported into vascular smooth muscle cells via cationic amino acid transporters, where they are metabolized into NO, polyamines, or L-proline. As effective vasodilators, they are commonly used to induce experimental acute pancreatitis models.

Monocrotaline is an 11-membered macrocyclic pyrrolizidine alkaloid extracted from the seeds of Crotalaria plants. It inhibits organic cation transporters OCT-1 and OCT-2, with IC50 values of 36.8 µM and 1.8 mM, respectively. Monocrotaline exhibits antitumor activity and shows certain cytotoxicity against liver cancer cells such as HepG2. It is also commonly used to induce pulmonary arterial hypertension models in rodents.