Role of endogenous prostaglandins in excitation contraction of skeletal muscle in rats

Prostaglandins are present in every mammalian tissue. Inhibition of their synthesis by piroxicam was used as a tool to study the role of endogenous PGs in nerve excitability, neuromuscular transmission and direct muscle contraction using isolated gastrocnemius-sciatic preparations from albino rats. It was observed that inhibition of PGs synthesis by piroxicam inhibited directly as well as and to a greater extent indirectly evoked muscle contractions. It decreased peak tetanic tension and produced tetanic fade. Its inhibitory effect on indirect muscle contraction was not reversed by prostigmine. Piroxicam inhibited also acetyl choline-induced-and caffeine induced contractures. But, there was no significant effect on rheobase, utilization time and chronaxia of sciatic nerve by inhibition of PGs synthesis

serum magnesium level in ischemic heart disease and relathionship to cardiac complications

To evaluate the serum magnesium [Mg] levels in patients with ischemic heart disease [IHD], eighty five patients with IHD were selected from patients of coronary care unit in Mansoura University Hospital 52 with chronic IHD without myocardial infraction [MI] and 33 cases with acute MI 25 cases out of the 52 patients with chronic IDH were presented by arrhythmias and remaining 27 patients had no arrhythmias-On the other hand 16 cases with acute MI were presented by arrhythmias and remaining 17 patients were non arrhythmic. In the present study the mean serum Mg levels in patients with IHD- with and without AMI; patients with chronic IHD and patients with acute MI were significantly lower [p<0.001] than the level in normal controls. There was in significant decrease in mean serum Mg in subgroup with arrhythmias when compared to those without arrhythmias [p>0.05], however a insignificant decrease [p<0.001] was observed in patients with IHD [with and without MI] patients with chronic IHD develop left ventricular failure [LVF] when compared to those who escape this complication in the same group. Also there was significant hypomagnesemia in patients without acute MI who complicated by premature ventricular contraction [PVCs] when compared to normal controls from the present study we can conclude that hypomagnesemia- in addition to hypokalemia - is a predisposing factor to dangerous complication in patients with IHD and the addition of Mg to the conventional therapy can reduce the incidence of complications in these patients