Study of capillary filtration by double labelling I131-albumin and Tc99m red cells. Application to the pharmacodynamic activity of Daflon 500 mg.

The Tc99m albumin test can be used to confirm idiopathic cyclic oedema (ICO) syndrome by a pathological retention of albumin of more than 8% of the maximum level, following release of the tourniquet (results obtained in 420 patients compared with 100 healthy women). This test was completed by a study involving double labelling using I131-albumin and Tc99m red cells in ten healthy subjects and ten female patients with untreated ICO syndrome. The tests were repeated at a six week interval. Evaluation of retention levels after tourniquet release showed nil retention of red cells in both populations and nil albumin retention in the healthy subjects whilst it was pathological in the patients with ICO. The curve of decreasing radioactivity was often marked by irregular oscillations after tourniquet removal. Study of these oscillations by the Fast Fourier Transform revealed reproducible abnormalities in the low frequency zone only, between 37 and 28 mHz in the ICO patients. These abnormalities took the form of more frequent peaks with higher amplitudes than in the healthy subjects and were linked--in the case of excessive leak of albumin from capillaries--to lymphatic resorption. In the high frequency zone between 630 and 39 mHz, results corresponding to variations related to arteriovenous compliance were similar in both populations and by both tests. A double blind placebo-controlled trial in 30 patients with ICO was carried out to study the pharmacodynamic activity of a flavonoid, Daflon 500 mg (2 tabs daily for 6 weeks), which revealed a decrease in the degree of retention--initially high--of labelled albumin (p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)