[The complement system: an old story or target of new therapeutic approaches?]

Effects of C1 esterase inhibitor administration on intestinal functional capillary density, leukocyte adherence and mesenteric plasma extravasation during experimental endotoxemia

OBJECTIVE

To determine the effects of C1 esterase inhibitor (C1-INH) administration on intestinal functional capillary density, leukocyte adherence, and mesenteric plasma extravasation during experimental endotoxemia.

DESIGN AND SETTING

Prospective, randomized, controlled animal study in the experimental laboratory of a university.

SUBJECTS

42 male Wistar rats.

INTERVENTIONS

The animals were divided into three groups. One half of the animals of each group underwent studies of intestinal functional capillary density and leukocyte adherence on venular endothelium by intravital fluorescence microscopy. In the other half of the animals mesenteric plasma extravasation (FITC albumin) was determined by intravital fluorescence microscopy. Treatment groups received endotoxin infusion of 2.5 mg/kg per hour (group 2 and 3) and 100 U/kg b.w. C1-INH (group 3) during the 2 h of endotoxemia.

MEASUREMENTS AND RESULTS

Endotoxemia resulted in a significant decrease in mucosal functional capillary density (18.5% vs. controls), which was reduced by C1-INH administration (9.5%). Treatment with C1-INH also significantly attenuated intestinal leukocyte adherence in submucosal venules (35% vs. endotoxin group) and mesenteric plasma extravasation (44% vs. endotoxin group).

CONCLUSIONS

C1-INH administration diminishes endotoxin-induced changes in the intestinal microcirculation during experimental endotoxemia.

C3 in seminal plasma has no additional informative value in the diagnosis of infection/inflammation of the male genital tract

The objective of this study was to determine the clinical significance of complement fraction C3 (C3c) in seminal plasma. Therefore 120 samples from randomly chosen subfertile males without signs of genital tract infection were screened for C3 and for seminal leucocytes as markers for subclinical infection/inflammation. A comprehensive semen evaluation included sperm analysis, sperm migration testing, immunocytochemical round cell differentiation to determine seminal leucocyte counts and the leucocyte ratio and semen cultures, in aliquots of the same ejaculates. C3 concentrations were significantly correlated with leucocyte counts per ml (P < 0.002) and per ejaculate (P < 0.001), and with the leucocyte ratio (P < 0.001). No association of C3 concentrations with semen quality or with the bacterial colonization of semen samples was found. The significant association with seminal leucocytes suggests that C3 might be used as an additional marker for silent male genital tract infection. In comparison with semen leucocytes, C3 screening does not reveal any further information about semen quality or infection/inflammation pathogenesis of the male genital tract.