Salusin Beta (SALb)

Salusins are two newly discovered TOR-related peptides consisting of 28 and 20 amino acids and designated salusin-alpha and salusin-beta, respectively. Salusins are bioactive peptides with hemodynamic and mitogenic activities. Salusins improve calcium uptake and protein synthesis in neonatal rat cardiomyocytes, suggesting that salusins may be regulatory factors for myocardial growth and hypertrophy. Intravenous administration of salusin-alpha or salusin-beta to rats causes rapid, profound hypotension and bradycardia. Salusins increase intracellular Ca(2 ), upregulate a variety of genes and induce cell mitogenesis. Salusin-beta stimulates the release of arginine-vasopressin from rat pituitary. Expression of TOR2A mRNA and its splicing into preprosalusin are ubiquitous, and immunoreactive salusin-alpha and salusin-beta are detected in many human tissues, plasma and urine, suggesting that salusins are endocrine and/or paracrine factors.