Digibind attenuates cytokine TNFalpha-induced endothelial inflammatory response: potential benefit role of digibind in preeclampsia

Erythrocyte Na+-Li+ counter-transport activity and digoxin-like substances in insulin dependent diabetic women with preexisting preeclampsia

AIM OF THE STUDY

To determine whether there is pathogenetic link between red cells sodium-lithium counter-transport activity and digoxin-like immunoreactive substances (DLIS) in plasma of insulin-dependent diabetic (IDDM) and non-diabetic women with preexisting preeclampsia (PE).

SUBJECTS AND METHODS

We studied Na(+)/Li(+) CT activity in red cells and plasma levels of DLIS in 11 IDDM women with preexisting PE (Group 1), 13 IDDM without preexisting PE (Group 2) 23 non-diabetic women with preexisting PE (Group 3) and 12 non-diabetic women with normal pregnancy (Group 4) at least 4 months after delivery.

RESULTS

Na(+)/Li(+) CT activity was higher in Group 1 compared to Group 2 (mean ± SEM 0.316 ± 0.05 vs 0.190 ± 0.02 mmol/LRBC/hr p < 0.05) and in Group 3 compared to Group 4 (0.365 ± 0.004 vs 0.168 ± 0.01 mmol/LRBC/hr, p < 0.01). Plasma levels of DLIS were higher in Group 3 compared to Group 4 (0.727 ± 0.189 vs 0.295 ± 0.066 ng/ml; p<0.05); there was no statistically significant difference between the two diabetic groups. In Groups 1 and 3, Na(+)/Li(+) CT activity was correlated to the plasma levels of DLIS (r = 0.927; p < 0.001 and r = 0.485; p<0.05 respectively).

CONCLUSION

Increased Na(+)/Li(+) CT activity and increased plasma levels of DLIS may contribute to PE in IDDM and non-diabetic women.

Risk factors and mediators of the vascular dysfunction associated with hypertension in pregnancy

Normal pregnancy is associated with significant hemodynamic changes and vasodilation in the uterine and systemic circulation in order to meet the metabolic demands of the mother and developing fetus. Hypertension in pregnancy (HTN-Preg) and preeclampsia (PE) are major complications and life-threatening conditions to both the mother and fetus. PE is precipitated by various genetic, dietary and environmental factors. Although the initiating events of PE are unclear, inadequate invasion of cytotrophoblasts into the uterine artery is thought to reduce uteroplacental perfusion pressure and lead to placental ischemia/hypoxia. Placental hypoxia induces the release of biologically active factors such as growth factor inhibitors, anti-angiogenic proteins, inflammatory cytokines, reactive oxygen species, hypoxia-inducible factors, and antibodies to vascular angiotensin II receptor. These bioactive factors affect the production/activity of various vascular mediators in the endothelium, smooth muscle and extracellular matrix, leading to severe vasoconstriction and HTN. As an endothelial cell disorder, PE is associated with decreased vasodilator mediators such as nitric oxide, prostacyclin and hyperpolarizing factor and increased vasoconstrictor mediators such as endothelin, angiotensin II and thromboxane A(2). PE also involves enhanced mechanisms of vascular smooth muscle contraction including intracellular free Ca(2+) concentration ([Ca(2+)](i)), and [Ca(2+)](i) sensitization pathways such as protein kinase C, Rho-kinase and mitogen-activated protein kinase. Changes in extracellular matrix composition and matrix metalloproteases activity also promote vascular remodeling and further vasoconstriction in the uterine and systemic circulation. Characterization of the predisposing risk factors, the biologically active factors, and the vascular mediators associated with PE holds the promise for early detection, and should help design specific genetic and pharmacological tools for the management of the vascular dysfunction associated with HTN-Preg.