Effects of pharmacological agents on the activity of rat kidney adenylyl cyclase

To study the effect of both selective and nonselective activator and inhibitory agent on adenytyl cyclase in rat kidney. Design: Different concentrations of some pharmacological agents such as forskolin, nebularine, Ap4A, AP3A and caffeine were prepared. The effects of the agents on the activity of rat kidney adenylyl were determined. The crude extract obtained from rat kidney tissue was prepared and the specific activity of adenylyl cyclase in the crude extract was determined by using [2-H3] ATP as substrate which produced cAMP Different concentrations of important pharmacological agents as activators and inhibitors of enzyme were examined. The compounds selected were forskolin as a known activator of adenylyl cyclase and for comparison; nebularine, Ap4A, APA and caffeine were used. The results obtained showed that the highest activity of adenylyl cyclase was at 100uM forskolin. The activity of enzyme was inhibited by nebularine as the concentration of agent was increased until at 50uM where the inhibition began to level off. The effect of caffeine at 10-300uM on the activity of adenylyl cyclase showed no significant effect on the enzyme activity in kidney tissue. APA showed no effect on the activity of adenylyl cyclase over the concentration range of 10-300uM, whereas, APA produced an inhibition effect on the enzyme activity at concentration 100uM. The important role of cyclic nucleotides in cell-signaling and metabolism control, evoke the activities and inhibitors of cyclase to play a potential physiological effects. As forskolin is well known activator of adenylyl cyclase, other pharmacological agents such as nebularine and Ap4A are found to be a potential inhibitors of cyclase, which highlight these compounds as treatment of mania, schizophrenia, seizure and parkinson's diseases in which an increase of cAMP concentration has been demonstrated

Vitamin D status and serum level of some elements in children with sickle cell disease in Jeddah, Saudi Arabia

To study the relationship of Vitamin D deficiency and some minerals metabolism in the children with sickle cell disease [SCD] in the city of Jeddah, western region of Saudi Arabia. Design: Measuring the concentration of serum 25[OH] Vitamin D, calcium, phosphorus and magnesium in children with SCD aged between newborn to 12 years old. A total of 51 children with sickle cell disease [both gender] included 28 males [54.9%] and 23 females [45.1%] aged between newborn and 12 years old and 70 healthy matching controls were admitted or visited sickle cell section in the Maternity and Children Hospital in the city of Jeddah. Fasting blood samples were collected and the serum was separated and stored at '30'C until the time of analysis. Serum 25 [OH] Vitamin D was determined using a commercially available kit [VDBP,Gc globulin], calcium, phosphorus and magnesium were measured using a clinical autoanalyser. The patients were divided into two groups according to the ages. Group-A included 21 patients [both gender] aged between newborn and 6 years, group-B included 30 patients [both gender] aged between 7-12 years. The results obtained showed that the serum concentrations of 25[OH] Vitamin D in both patients groups were significantly lower than the healthy matching controls [P<0.01 and P<0.001], respectively. The serum concentrations of calcium, phosphorus and magnesium in group-A patients had no significant differences, whereas in group-B, the concentration of Ca+2 was significantly lower in patients than the controls [P<0.05], no significant differences in P in both groups [P>0.05] and significantly higher in the serum magnesium of group-B [P<0.05]. A significant relation between Vitamin D deficiency and children with sickle cell disease which is normal due to confined patients indoor. The serum calcium concentration had no affect in the early stage of ages but a significant lower appeared with increasing of ages. The serum magnesium concentration was higher in group-B which can be explained to the important role of Mg+2 in the nature of erythrocyte membrane in sickle cell patients