Abstract: Described are derivatives of the precursor peptide of the cardiodilatin/atrial sodiuretic factor (CDD-ANF) or fragments thereof which comprise at least the amino acid sequence of alpha-hANaP. The derivatives according to the present invention are compounds of the formula (I) ##STR1## X is a phosphate or thiophosphate group. R is NH.sub.2 or a peptide fragment from the amino acid sequence of gamma-hANaP. Radio-labelled derivatives are also possible. A method for the qualitative and/or quantitative determination of peptides containing the sequence of alpha-hANaP and a use of the compounds having the formula (I) as medicaments for various vaso- and renal related disorders are further described.

Abstract: Described is a peptide fragment which comprises the amino acid sequence 95-126 of ANF/CDD 1-126 (gamma-hANaP) and is formed in the kidney. The fragment urodilatin (ANF/CDD 95-126) has the following amino acid sequence: ##STR1## wherein R.sup.1 and R.sup.2 each represent further peptide fragments of ANF/CDD 1-126 (gamma-hANaP). In the amino acid sequence R.sup.1 is Thr-Alo-Pro-Arg-Ser-Leu-Arg-Arg-Ser-Ser and R.sup.2 is Asn-Ser-Phe-Arg-Tyr. Further described are processes for the preparation and/or recovery of the new peptide fragment and a medicament containing urodilatin (ANF/CDD 95-126 ) as well as medical indications of the medicament.

Abstract: A device for the removal of active substances locally applied against solid tumors consists of a catheter (1) to be positioned distally to the tumor for the collection of blood coming from the tumor, a pump (2) anda catheter (3) connected thereto and returning the blood into the body. The device is characterized in that between the two catheters (1, 3) there is present at least one container (4) capable of allowing blood to pass therethrough and containing immobilized antibodies against the applied active substance.