Abstract: This invention teaches a method for determining the hormone cardiodilatin active fragments thereof, well as antibodies thereto.

Abstract: There is described a new peptide hormone (cardiodilatin) and a process for its preparation, with the amino acid sequence: Asn-Pro-Val-Tyr-Gly-Ser-Val-Ser-Asn-Ala-Asp-Leu-Met-Asp-Phe-Lys-Asn-Leu-Le u-Asp-His-Leu-Glu-Asp-Lys-Met-Pro-Leu-Glu-Asp-Glu-Ala-Met-Pro-Pro-Gln-Val-L eu-Ser-Glu-Gln-Asp-Glu-Glu-Val-Gly-Ala-Pro-Leu-Pro-Leu-Leu-Glu-Glu-Val-Pro- Pro-Trp-Thr-Gly-Glu-Val-A n-Pro of the composition Asp/Asn 14, Thr 3, Ser 15, Glu/Gln 12, Pro 10, Gly 12, Ala 10, Val 7, Met 4, Ile 1, Leu 15, Tyr 2, Phe 3, Lys 4, His 2, Arg 10, Trp 2, a molecular weight of 13000 Dalton and an isoelectric point I.P. of 6 to 6.5.The peptide hormone, as well as its C-terminal fragments obtained after partial cyanogen bromide fission between and behind Met groups, possess a high relaxing action on the smooth bloodvessel musculature.

Abstract: The present invention provides a carrier such as polyethylene having covalently bound to it a reaction component such as an antibody, for use for immune determinations. The reaction component is covalently bound via heterobifunctional photoactivatable compounds, one group of which is found by an aryl azide group. Protein A may be bound covalently to the carrier via heterobifunctional photoactivatable compounds, and antibodies bound to the protein A.