Saralasin

Saralasin ([Sar1, Ala8] Angiotensin II) is an octapeptide derivative of angiotensin II. Saralasin acts as a competitive antagonist of the angiotensin II receptor, with a Ki value of 0.32 nM (occupying 74% of the binding sites), and also possesses partial agonist activity. Saralasin can be used in research on renovascular hypertension and renin-dependent (i.e., angiotensinogen-dependent) hypertension.

HEK293 cells:4 x 10-10 M

Method: Under ex vivo conditions, rat kidney tissue was placed in a tissue bath and exposed to increasing concentrations of Saralasin (10⁻⁹ to 10⁻⁵ M). Changes in renal microvascular diameters were observed using television microscopy, and relative glomerular blood flow was measured using fluorescently labeled red blood cells.

Result: Saralasin dose-dependently dilated both preglomerular and postglomerular vessels and increased glomerular blood flow [1].

Method: Mice were subjected to transverse aortic constriction (TAC) to induce left ventricular pressure overload. Cardiac structure and electrophysiological changes were observed in vivo at short-term (1-2 days) and long-term (1-2 weeks) intervals. After euthanizing the animals, heart-to-body weight ratios were measured, and left ventricular myocytes were acutely isolated for electrophysiological recordings.
Result: Short-term in vivo pressure overload did not induce cardiac hypertrophy (no significant change in heart-to-body weight ratio) but caused a significant reduction in I_to,fast and I_K,slow, which could be reversed by ex vivo saralasin treatment. Long-term in vivo pressure overload induced significant cardiac hypertrophy (30% increase in heart-to-body weight ratio and 27% increase in cell capacitance). The reduction in total I_to,fast current could be reversed by saralasin, whereas I_K,slow did not respond to saralasin, suggesting a functional uncoupling between the current and the receptor after long-term overload [2].
Method: Conscious rats on normal or low-sodium diets were subcutaneously injected with saralasin (10 mg/kg or 30 mg/kg). Twenty minutes after injection, the animals were euthanized and blood was collected. Serum renin activity (SRA) was measured using the antibody trapping method.
Result: Saralasin dose-dependently increased serum renin activity in normal rats, from 2.7±0.4 ng/ml/hr in controls to 16.2±3.7 ng/ml/hr in the 10 mg/kg group and 22.5±2.4 ng/ml/hr in the 30 mg/kg group (P<0.001). In low-sodium diet rats, saralasin (0.3 mg/kg) increased serum renin activity from 12±2 ng/ml/hr to 119±6 ng/ml/hr (P<0.001) and mildly reduced blood pressure by 6% (P<0.01) [3].

DMSO: 40 mg/mL (43.86 mM), Sonication is recommended.

H2O: 1.00 mg/mL (1.10 mM), Sonication is recommended.