cardiac stimulating activities

Isoprenaline hydrochloride (Isoproterenol hydrochloride) 是一种 β-肾上腺素能受体激动剂，具有非选择性和口服活性。Isoprenaline hydrochloride 可以扩张支气管，提高心率和心输出量，而不会收缩血管。

β-Endorphin (β-EP) is an endogenous opioid neuropeptide with diverse biological activities. It is produced via piomelanocortin cleavage in the pituitary gland, hypothalamus, and in lymphocytes, then migrates to its sites of action which include plasma, gut, skin, placenta, cerebrospinal fluid, and cardiac tissues. β-EP induces concentration-dependent decreases in electrically stimulated contraction of the mouse vas deferens that can be reversed by the μ-opioid antagonist CTP and δ-opioid antagonist ICI 174,864. In vivo, β-EP (5 μg, i.c.v.) slows gastrointestinal transit in mice. β-EP (0.5 or 5 μg, i.c.v.) stimulates food intake in rats for 4 to 6 hours, however, this effect is not prolonged with continuous infusion. It antagonizes the appetite-suppressive effects of α-melanocyte-stimulating hormone (α-MSH) for the first three days post administration. β-EP also reduces paralytic demyelination induced by the murine coronavirus MHV-JHM in immunocompetent, but not irradiated or immune-incompetent, mice and rats.

YS-49 (单水合物) 作为PI3K Akt（RhoA的下游靶点）的激活剂，有效降低3-甲基胆碱处理的细胞中RhoA PTEN的活性。此外，YS-49通过促进血红素加氧酶（HO-1）的表达，抑制血管紧张素II（Ang II）诱导的血管平滑肌细胞（VSMC）增殖。作为一种异喹啉化合物生物碱，YS-49因激活心脏β-adrenoceptors而显示出显著的正性肌力效应。