Determination of human low molecular weight kininogen by immunoassay.

It was the aim of the present investigation to develop a convenient method for determination of human kininogens. Using mono- and polyclonal antibody preparations an ELISA-system for specific determination of LMWK could be developed. In addition, the specificity of the monoclonal antibody suggests that their epitope in HMWK and its heavy chain is different to that in LMWK.

[Glomerular prostaglandins: synthesis, mechanism of action and interaction with ACE inhibitors]. / Glomeruläre Prostaglandine: Synthese, Wirkungsweise und Wechselwirkung mit ACE-Hemmern.

Prostaglandins (PG) play an important role in the regulation of the renal blood flow and glomerular filtration rate. This study was designed to examine PG synthesis in the presence and absence of the ACE inhibitor captopril, PG binding to specific receptors and the ability of PG to stimulate cAMP accumulation in isolated glomeruli. Glomeruli were isolated from rat kidneys by a passive mechanical sieving technique. PG synthesis was determined by RTLC and RIA. The main eicosanoids synthesized by glomeruli were PGF2 alpha, thromboxane (TX) A2 (measured as TXB2), PGI2 (measured as 6-keto-PGF1 alpha) and PGE2. Binding experiments were performed with PGE1, PGE2 and the PGI2 analogue iloprost. Scatchard analysis revealed that the specific binding was highest for PGE1, followed by iloprost and PGE2. Adenylate cyclase was preferentially stimulated by PGE1 and PGE2, and to a lesser extent by PGI2, whereas PGF2 alpha had almost no effect. Captopril reduced mainly TXB2 concentrations. Glomerular TXB2 reduction, therefore, seems to be an additional hypotensive effect of captopril medication.