Imbalance between free radical propagation and some antioxidants in patients with cataract

The relation of oxidative stress to the occurrence of cataract remains to be undetermined and must be clarified. So, the aim of this work was to study the effect of O2-free radical and some antioxidants in the pathogenesis of senile and diabetic cataract. This work was carried on 30 patients and 10 healthy subjects as control. They were 23 males and 17 females. Their ages ranged from 50 to 64 years. Patients were classified into senile cataract, diabetic without cataract and diabetic cataract groups. Each group included 10 patients. The results of this work showed that, in patients with senile cataract, were non-significant increase of fasting serum glucose [FSG] and serum total bilirubin [serum T. bilirubin] compared with the control group. Serum lipid peroxide [S. LP] and serum ceruloplasmin [S. Cp] were. significantly increased [P<0.05] while plasma superoxide dismutase [SOD] and serum uric acid were significantly decreased [P<0.05] compared with the control group. Moreover, diabetic patients with and without cataract showed a significant increase of FSG, S. total bilirubin. S. LP, S. Cp, and S. uric acid [P<0.05] while plasma SOD was significantly decreased [P<0.05] compared with the control group. Comparative study of the diabetic cataract versus senile cataract and diabetic without cataract, our results showed a significant increase of FSG, S. LP, S. total bilirubin and S. Cp, while there was significant decrease of plasma SOD in diabetic cataract compared with both senile cataract and diabetic without cataract [P1<0.05 and P2<0.05], respectively. S. uric acid was significantly increased in diabetic cataract compared with senile cataract group [P1<0.05] while it was non-significantly increased compared with diabetic without cataract group. Also, aqueous humor study of diabetic cataract group versus senile cataract group showed that LP and uric acid were significantly increased [P<0.05] while SOD was significantly decreased [P<0.05]. Correlation study revealed that, age was significantly and positively correlated with LP, but negatively correlated with SOD both in serum and aqueous in all patient groups. FSG was significantly and directly correlated with serum and aqueous LP, uric acid, S. total bilirubin, and S. Cp in diabetics with and without cataract. Moreover, serum and aqueous LP was significantly and inversely correlated with serum and aqueous SOD in all patient groups, while, it was positively correlated with S. total bilirubin, and S. Cp in diabetics with and without cataract. We could conclude that the imbalance between generation of O2-free radical and plasma SOD may have an etiological implication in the occurrence of cataract

Effect of the H2 antagonist cimetidine versus famotidine on serum theophylline level and theophylline induced hypokalemia in rats

The effect of the H[2] antagonists on serum theophylline level was determined both directly by measuring serum theophylline concentrations at 0.5 - 1 - 2 - 4 and 6 hours after a single therapeutic dose of the drug [l0mg/kg intraperitoneally [IP]] in control [untreated] rats and in rats pretreated with Cimetidine [100 mg/kg] or famotidine [4 mg/kg] orally for 1 week and indirectly by determining the influence of these H[2] antagonists [in the above doses] on the degree of hypokalemia induced by a single high dose of theophylline [25 mg/kg Ip] [theophylline induced hypokalemia is believed to correlate well with serum theophylline level]. The results showed that Cimetidine consistently induced a statistically significant increase in serum theophylline level starting 1 hour after injection [10.3% [P<0.05] and thereafter [40.6 - 41.6 and 45.2% at 2-4 and 6 hours respectively [P<.0005]]. In contrast famotidine did not induce significant changes in serum theophylline level [P>.05] during the total duration of the experiment. Moreover, high dose theophylline induced a statistically significant reduction [P<.0005] in serum K+ from a control value of 3.9 +/- .06 to 3.5 +/- .047 mEq/L [10.25%]; pretreatment with Cimetidine resulted in a further reduction in serum K+ from 3.5 +/- .047 to 3.2 +/- 0.04 mEq/L [8.5% P<.0005] whereas pretreatment with famotidine resulted in an insignificant change [3.5 +/- .047 versus 3.4 +/- 0.07 mEq/L 2.8%P>.05]. Since H [2] receptor antagonists and theophylline may be given concurrently in more than one clinical setting [prophylactic against development of gastrointestinal symptoms of theophylline, in reflux oesophagitis occurring in as many as 30-60% of asthmatics or in patients with upper gastrointestinal bleeding who are intubated and maximally bronchodilated], clinicians should be alert to the significant interaction. Serum theophylline concentration should be measured periodically, measurement of serum potassium could also assist indirectly in prediction of serum theophylline level. Finally famotidine could be a safer alternative to cimetidine whenever H[2] antagonists are given concurrently with theophylline