Nifedipine versus isradipine as antiatherogenic modalities in cholesterol fed rabbits

The antiatherogenic effect of nifedipine and isradipine was experimentally studied in cholesterol fed-rabbits. Our results demonstrate that isradipine in therapeutic doses relevant to human use, has antiatherogenic activity in cholesterol-fed rabbit model. On the other hand nifedipine has a comparable effect but at doses that are much higher than equivalent human doses. Furthermore isradipine significantly increased [P 0.05], while nifedipine insignificantly decreased high density lipoprotein-cholesterol [HDL] level than in the non-atherosclerotic control group of rabbits. We concluded that isradipine, and not nifedipine. is an effective and applicable antiatherogenic modality in proper clinical setting

Effect of different oral doses of omeprazole on indomethacin-induces gastric ulcer in male albino rats

Omeprazole, a benzimidazole derivative, has proven to be a powerful inhibitor of gastric acid secretion evoked by variety of stimuli. This work was designed to study the effect of different doses of omeprazole [1.8, 3.7 and 7.2 mg/kg] on indomethacin-induced gastric ulcer and on indomethacin-induced changes of gastric acid secretion in male albino rats. Incidence of ulceration, mean ulcer score as well as ulcer and preventive indices were estimated to assess the former, while volume of gastric content, acid out put and acid concentration were estimated to assess the latter. Omeprazole [7.2 mg/kg] was the only dose that could reduce incidence of ulceration. Doses of [3.7 and 7.2 mg/kg] could significantly [P < 0.05] reduce mean acid concentration. However, other mentioned parameters were significantly [P < 0.05] reduced by all used doses in a dose dependant manner. It is obvious that [7.2 mg/kg] is the dose that reduced significantly all measured parameters but the beneficial effect of other doses cannot be discarded

Selectivity of pinaverium promide on gastrointestinal tract

Pinaverium bromide [PB] has been shown to exert a marked spasmolytic action in gastrointestinal disorders and does not proceed cardiovascular-side effects at therapeutic doses. Since relative selectivity of other calcium antagonists has already been demonstrated, in the present work the efficacy of PB as Ca[2+] antagonist on isolated intestinal smooth muscle, heart muscle and vascular muscle [aortic ring] of rabbit was studied. Also, its efficacy was compared with other standard calcium antagonists [Verapamil and nifedipine] on the same isolated tissues. Its effect on gastric ulcer and gastric acid secretion induced by indomethacin on male albino rats was also studied. Dose-dependent, Ca[2 antagonistic properties of PB were convincingly confirmed in the performed studies. The Ca[2+] antagonistic activity of this drug was found to be 15.2 and 2.8 times higher at the jejunal smooth muscle than at myocardial preparation and at vascular smooth muscle respectively. On the other hand verapamil was found to be more selective than PB on the isolated rabbit heart with potency ratio [PR] equal 17.3. As well as Nifedipine was found to be more selective than PB On the vascular smooth muscle with PR equal 57407.4. In addition PB in doses of 1.35 mg/100 rat produced a highest degree of prophylactic effect on gastric ulceration induced by indomethacin as well as a significant inhibition of indomethacin-induced gastric acid secretion. Accordingly, PB seems to be more selective for jejunal smooth muscle than at myocardial preparation and vascular smooth muscle. In addition it has a prophylactic effect on gastric ulcer and decreased gastric acid secretion

Different approaches in prevention of stress induced acute gastric ulcer: an experimental study on male albino rats

In a trial to approach the most probable mechanism in pathogenesis of stress gastric ulcer, three specific drugs destined to target the three incriminated mechanisms were selected. Twenty four male albino rats have been included, and divided into 4 equal groups [control [G1], omeprazole [G2], pirenzepine [G3], and clonidine [G4], groups]. Stress had been done by 24 hours immobilization. Incidence of ulceration was 100%, 100%, 66.67% and 33.33% in G[1], G[2], G[3] and G[4] respectively. In the same order mean ulcer scores were 3.5 +/- 0.224, 2 +/- 0.365, 0.67 +/- 0.21 and 0.33 +/- 0.21 with insignificant difference between G[3] and G[4] and a significant difference between each of them and G[1] and G[2]. Preventive indices were 42.86%, 92.5% and 96.86% in G[2], G[3] and G[4] respectively with insignificant difference between G[3] and G[4] and a significant difference between each of them and G[2]. We concluded that gastric mucosal ischemia seemed to be the man denominator in pathogenesis of stress induced gastric ulcer and clonidine seemed to be a potent preventive modality in this context