Angiotensin I and iodinated angiotensin I solutions are stabilized against enzymatic degradation by the addition of phenylmethylsulfonyl fluoride (PMSK). Such solutions are used as standards and reagents in immunoassay kits for determinatin of plasma renin levels. Stabilized solutions prepared in accordance with this disclosure can be shipped at ambient temperature which represents a substantial advantage in convenience over previously available solutions of angiotensin I and radioiodinated angiotensin I.
A method of stabilizing a solution of a radiolabeled compound comprising adding to such solution a compound having a substantially insoluble backbone, to which has been bound a quaternary ammonium group; or a water soluble primary, secondary or tertiary aliphatic amine. The present invention also includes a solution of a radiolabeled compound maintained in contact with such a compound, and as an article of manufacture, a sealed vial containing such a solution.
A composition of a mixture of a lactic acid producing bacteria culture and a lactate utilizing bacteria culture admixed with a dry formulation or an animal feedlot diet for improving the utilization of feedstuffs by a ruminant. The composition may be used on a continual basis to increase meat or milk production, or used during the transition from a roughage diet to a feedlot diet to prevent or minimize acidosis. The preferred embodiment utilizes Lactobacillus acidaphilus as its lactic acid producing bacteria culture and Propionibacterium P-5 as its lactate utilizing bacteria culture. The composition is in a dry powder form for storage at ambient temperatures for long durations.
