RESUMO
The underlying mechanism of dependence and rewarding effects of morphine is imperative to understand. The primary aim of this study was to investigate whether ropinirole D2/3 agonist affects the rewarding and reinforcing properties of morphine-induced conditioned place preference (CPP) and withdrawal syndromes in rats. On day one, the animals were randomly divided to conduct the pre-test. The morphine (10 mg/kg, i.p.) and/or saline was administered on alternate days in an 8-day CPP session. On day 10, 15 min prior to the post-conditioning test (expression), a single dose of ropinirole (1, 2, and 5 mg/kg, i.p.) was given to rats. In extinction session, ropinirole was injected daily, and CPP was extinguished by repeated testing, with intervals of 3 days. Finally, reinstatement was assessed by administering ropinirole (1, 2, and 5 mg/kg) 15 min before the morphine injection. Morphine dependence was developed by administering increasing doses of morphine (10-50 mg/kg, i.p.). To assess withdrawal symptoms, ropinirole (1, 2, and 5 mg/kg) was injected 15 min before naloxone (2 mg/kg, s.c.) administration. The present study confirms that ropinirole attenuates expression and reinstatement of CPP, while it precipitates the extinction of morphine-induced CPP. Naloxone-precipitated morphine withdrawal symptoms, including wet dog shakes and weight loss, were attenuated although jumping was increased by a single ropinirole injection. Thus, ropinirole was influential in attenuating expression, reducing drug seeking and weakening reinstatement via the dopaminergic system. These findings show that ropinirole might affect neuro-adaptive changes related to dependence.
RESUMO
OBJECTIVE: The influence of the Ramadan fasting on blood pressure (BP) in patients taking diuretics therapy has not been addressed specifically yet. The aim of this study was to examine the effect of long Ramadan fasting on BP with ambulatory BP monitoring in hypertensive patients using diuretics. METHODS: This prospective, observational study was done on 129 hypertensive patients and was carried out in two groups: 73 treated hypertensive patients were assigned to the diuretic group and 56 treated hypertensive patients were allocated to the non-diuretic group. Twenty-four-hour ambulatory BP monitoring was performed during and after Ramadan. Mean overall, daytime and nighttime BP were measured and compared in both groups. The differences in mean SBP and DBP were recorded between the two monitoring periods. RESULTS: In diuretic group, 24-h SBP decreased from 128.2 ± 17.9 to 119.3 ± 9.5 mmHg during Ramadan (8.9 units; P < 0.001). DBP decreased from 79.4 ± 10.9 to 75.3 ± 7.6 mmHg (4.1 units; P < 0.001). On the other hand, SBP and DBP were lower insignificantly in the non-diuretic group. The reduction in SBP was significantly higher in the diuretic group (overall: P = 0.005, daytime: P = 0.011, nighttime: P = 0.022). Thiazide-like diuretics lowered BP more than thiazide-type diuretic despite an insignificant difference. CONCLUSION: This study suggested that Ramadan fasting might cause significant reductions in mean SBP and DBP measurements in patients using diuretics. Despite decreasing in BP, diuretics generally well tolerated and can be safe in well-controlled hypertensive patients during Ramadan fasting.