Adrenomedullin (22-52) is a C-terminal fragment of adrenomedullin (1-52) . In vitro, adrenomedullin (22-52) reduces basal corticosterone production in a mixture of rat adrenocortical and adrenomedulllary cells. It also reverses increases in ACTH-stimulated corticosterone production induced by adrenomedullin (1-52). Adrenomedulin (22-52) (0.5 and 5 μg/kg/min) has no effect on basal regional cerebral blood flow but reverses increases in regional cerebral blood flow induced by rat adrenomedullin in rats. Unlike adrenomedullin (1-52), adrenomedullin (22-52) has no effect on mesenteric arterial perfusion pressure in cats.
N-Arachidonoyl-L-serine (ARA-S), a recently isolated endocannabinoid with a distinct activity profile that diverges from typical endocannabinoids, does not interact with central cannabinoid (CB1), peripheral cannabinoid (CB2) receptors, or vanilloid receptor 1 (VR1). Unlike other compounds, ARA-S (5 mg kg) counteracts the lowering of blood pressure induced by a 10 mg kg intravenous bolus of abnormal cannabidiol (Abn-CBD) in anesthetized rat models. Additionally, akin to Abn-CBD, ARA-S induces relaxation in isolated rat mesenteric arteries and abdominal aorta and promotes phosphorylation of Akt and mitogen-activated protein kinase (MAPK) in human umbilical vein endothelial cells (HUVEC). The mechanisms through which ARA-S and Abn-CBD exert their effects on vascular systems show variations and merit deeper investigation.