S100A1: a major player in cardiovascular performance

Calcium cycling is a major determinant of cardiac function. S100A1 is the most abundant member of the calcium-binding S100 protein family in myocardial tissue. S100A1 interacts with a variety of calcium regulatory proteins such as SERCA2a, ryanodine receptors, L-type calcium channels and Na(+)/Ca(2+) exchangers, thus enhancing calcium cycling. Aside from this major function, S100A1 has an important role in energy balance, myofilament sliding, myofilament calcium sensibility, titin-actin interaction, apoptosis and cardiac remodeling. Apart from its properties regarding cardiomyocytes, S100A1 is also important in vessel relaxation and angiogenesis. S100A1 potentiates cardiac function thus increasing the cardiomyocytes' functional reserve; this is an important feature in heart failure. In fact, S100A1 seems to normalize cardiac function after myocardial infarction. Also, S100A1 is essential in the acute response to adrenergic stimulation. Gene therapy experiments show promising results, although further studies are still needed to reach clinical practice. In this review, we aim to describe the molecular basis and regulatory function of S100A1, exploring its interactions with a myriad of target proteins. We also explore its functional effects on systolic and diastolic function as well as its acute actions. Finally, we discuss S100A1 gene therapy and its progression so far.

Anti-inflammatory and analgesic activities of the latex containing triterpenes from Himatanthus sucuuba

Some triterpenes and iridoids were previously isolated from the stem bark of Himatanthus sucuuba. The latex from Himatanthus sucuuba is used in popular amazonian medicine as an anti-inflammatory remedy. Fractions of the latex were pharmacologically evaluated with a view to verify this popular use in the carrageenan-induced rat paw edema and in the acetic acid-induced mouse constriction tests. The hexane fraction inhibited the edema formation by 35.9% at a dose of 200 mg/kg (p.o.) but no activity was observed at 100 mg/kg (p.o.). The triterpenes present in the hexane fraction were identified as lupeol acetate, alpha-amyrin and lupeol cinnamates. The fraction containing only cinnamates inhibited the edema and the abdominal constrictions by 50-40% and 57.9%, respectively, at 100 mg/kg (p.o.). Among all the fractions studied, the fraction containing only cinnamates showed the greatest anti-inflammatory activity which suggests that these compounds were responsible for the previously described activity of the crude extract.

The large septal arteries in normal hearts, in aortic valve disease, and in tetralogy of Fallot

BACKGROUND

Several surgical techniques such as the Ross operation or total correction of tetralogy of Fallot require incisions of the upper ventricular septum. Very few reports on the anatomy of the septal arteries of the pathologic heart can be found in the literature. To get a more precise knowledge of the large septal arteries in pathologic hearts, we have compared the anatomy of normal hearts with that of hearts with aortic valve disease and of tetralogy of Fallot.

METHODS

Twenty-six normal heart specimens (group A), 11 with aortic valve disease (group B), and 4 with tetralogy of Fallot (group C) were dissected.

RESULTS

In groups B and C a single large septal artery was always found. The large septal artery had the orientation previously described for normal hearts. Still, its course in the lower border of the anterior extension of the septomarginal trabecula was deeper. The anterior extension of the septomarginal trabecula was 4 +/- 3 mm deep in group A, 6 +/- 2 mm in group B, and 3 mm in group C. The interventricular septum was much thicker in groups B and C than in group A.

CONCLUSIONS

The position of the large septal artery can be predicted from coronary angiography and from the morphology of the anterior extension of the septomarginal trabecula. Knowledge of its position can improve the safety of operations performed on the outflow of the interventricular septum.

[Erythrocytic enzymatic systems and their antioxidative potential in pregnant women undergoing labor induction with intracervical PGE2]

Our purpose is to correlate, the apgar score of the new-borns from induction of labour (IL) with Prostaglandin E2 (PGE2) endocervical gel, and the oxidative environment of the pregnant woman during labour, studying biochemical markers of the erythrocytes. PGE2 is responsible for the regulation of the vascular response in pregnancy, namely for the vasoconstriction caused by Angitensin II. The production of Prostaglandins in vivo depends on mechanisms related to free radicals of oxygen (FRO). The production of FRO is enhanced in normal pregnancy. We have studied two erythrocytic enzymes and plasmatic concentration of PGE2 before and after the IL. Those enzymes are oxireductases-the transmembrane reductase (RTM) and the metahemoglobin reductase (MHR). Their function is to prevent the effects of the FRO on cellular biomolecules namely the endothelium and the red blood cells. This prevention of oxidative stress can facilitate the deformability of the erythrocytes, so these cells can easily transpose the small vessels and bind the oxygen to the tissues. The activity of those enzymes can be modulated by PGE2 used in the IL. We have not found significant variations on the activity of RTM after IL. The activity of MHR was enhanced with statistical significance, 30 minutes after the induction. This enhancement of activity can be a mechanism to prevent the oxidative stress of the induction of labour.