influence of L-carnitine among other agents on the functional recovery of the isolated rat heart exposed to hypoxic cold cardioplegia

L-carnitine, is an amino acid derivative, that has previously shown a beneficial effect on skeletal and cardiac muscle function through favorable metabolic effects. This study aims to test for a possible protective effect of L-carnitine in face of cold hypoxic cardioplegia of the isolated rat heart. Sixty male albino rats were used in this study and were divided into six study groups. Isolated rat hearts from all the study groups were exposed to hyperkalemic, hypoxic cold cardioplegia for two hours with the following changes in the cardioplegic solution: Group I served as a control group with no special additions to the cardioplegic solution; for Group II, glucose in the cardioplegic solution was increased to a concentration of 22millimole [mM] for Group III methylprednisolone sodium succinate [MPSS] was added to a concentration of 100mg per liter; Group IV received verapamil in the cardioplegic solution at a concentration of 1.1 micromol/L; Group V had L-carnitine at a concentration of 1mM and for Group VI, L-carnitine was added to the cardioplegic solution a t a concentration of 4Mm. The heart rate [HR], Dp/dt, the left ventricular developed pressure [LVDP], and rate pressure product [RPP] were recorded at baseline, and at 15 and 60 minutes after the start of re-warming. Epinephrine was given to the working hearts at doses of 0.5, 1.0 and 2.0 micromol before cardioplegia and after re-warming and the changes in cardiac function parameters in response to epinephrine were recorded. Creatine phosphokinase [CPK] was measured in samples from the coronary effluent taken before cardioplegia and 15 minutes after re-warming. The control group showed a significant reduction in all cardiac function parameters after cardioplegia and re-warming [dp/dt[max], LVDP and RPP reached 40.2%, 18.8% and 8.4% of their baseline values respectively]. Significant cardiac protection was noted in the groups exposed to glucose and carnitine. Functional recovery with glucose reached 66.2% of the baseline value for the dp/dt[max], 55.2% for the LVDP and 17.5% for the RPP [p<0.01 as compared to control]. Functional recovery with carnitine 4mM reached 98.7% of the baseline value of dp/dt[max], 89.9% for the LVDP, 48.1% for the RPP [p<0.05 as compared to all the other groups]. For carnitine at the 4mM concentration the dp/dt[max] values at the end of the experiment showed no significant difference from the baseline values. Also the percentage increase in dp/dt[max] and LVDP in response to post-cardioplegic epinephrine showed no significant difference from that recorded before cardioplegia [p>0.05]. MPSS provided only transient cardiac improvement compared to the control group, while verapamil showed no protective action on cardiac function parameters. CPK results showed significantly lower post re-warming CPK with all the tested drugs

Gene expression of vasopressin receptor type 2 and aquaporin 2 in acute renal failure versus chronic renal failure in rats

Urinary concentration decreases in response to a reduction of functioning renal mass. Although a variety of factors have been implicated, the pathogenesis of impaired urinary concentration ability in acute renal failure [ARF] and in chronic renal failure [CRF] especially the cellular and molecular defects, were poorly understood. Our study therefore aimed to present a possible explanation for the pathogenesis of impaired urinary concentration and the molecular defect in kidney tissue of experimental ARF and CRF rat models and aimed to find and compare any molecular defect difference between ARF and CRF. Thirty albino adult male rats were used in our study and the animals were divided into three groups. Group I: Sham-operated controls [n=10]. Group II: Renal ischemia-reperfusion injury group [n=10] in which the renal artery and vein were bilaterally exposed and occluded for 30min with vascular clamps to produce renal ischemia-induced acute renal failure [ARF], the clamps were removed to allow kidney reperfusion then the animal sacrified after 24H. Group III: Chronic renal failure group [n=10], this group of animals underwent right total nephrectomy and removal of 2/3 of the left kidney and the experimental protocol lasted about one month then the animals were sacrified. Blood, urine and kidney tissue samples were collected from the three groups to measure serum urea and creatinine and 24 hour-urinary albumin for evaluation of kidney function and to measure aquaporin 2 water channel and vasopressin-receptor type 2 [V[2]] gene expressions in kidney tissue. Kidney function tests as regards serum urea, serum creatinine and 24 hour-urinary albumin in group II and group III showed a significant [p<0.05] increase in comparison to control group [group I]. Ischemic-reperfusion rats [group II] showed the highest of these parameters indicating that, they had the worst kidney function. A significant [p<0.05] decrease in vasopressin-receptor type 2 [V[2]] mRNA expression in kidney tissue was shown in group II [ARF] and group III in comparison to the control rats [group I] with the highest reduction in group II. A similar result was found as regards Aquaporin 2 water channel mRNA expression with a significant [p<0.05] reduction in group II and group III in comparison to group I, and the highest reduction was seen in group II among the three studied groups. In both ischemia-reperfusion rats and CRF rats, the ischemic and nephrectomy insults were associated with decreased mRNA expression of the aquaporin 2 and vasopressin-receptors type 2 [V[2]] in the kidney tissue, coinciding with the impairment of kidney function. This may contribute to the impairment in urinary concentration in the post-ischemic period and the urinary concentration defect associated with CRF

Sex hormones and adrenocorticotropic hormone [ACTH] alterations during sleep deprivation and recovery in adult male rats

Positive association between sleep efficiency and plasma testosterone level in men was demonstrated by previous studies. Stresses in general and sleep deprivation in particular alter the male reproductive function and several studies indicate that sleep deprivation alters male sex hormones levels. Low sleep efficiency was associated with attenuated testosterone level. However, little information was available about the alterations of male sex hormones during the recovery period following the sleep deprivation. So, the purpose of the present study was to investigate the influence of 4-days recovery periods after 4-days sleep deprivation on male sex hormones and the role of ACTH hormone during both deprivation and recovery periods. Sixty four male albino rats weighing 200-250g each, were randomly distributed into three experimental sets: sleep deprived [SD] groups, recovery [R] groups and control group. The SD rats [n=24] were divided into 4 groups: SD1, SD2, SD3, and SD4 groups [each included 6 rats] that were subjected to SD for 1, 2, 3, and 4 days respectively. The recovery rats [n=24] were also divided into 4 groups [each included 6 rats] that were sleep deprived for 4 days and had left for recovery for 1, 2, 3, and 4 days; corresponding to R1, R2, R3 and R4 groups respectively. Finally, the control group included 16 rats. At the end of each group preparation, rats [control, SD and R] were sacrificed and plasma samples were collected for further measurement of testosterone, estradiol, progesterone and ACTH hormones. Compared to control rats, SD rats showed a significant [p

Study of whole blood glutathione peroxidase enzyme activity and serum selenium level in bronchial asthma and COPD

This study was carried out in Kasr El-Aini Hospital and included 70 age and sex matched subjects who were divided into three groups. Group I included 25 patients with bronchial asthma, group II included 25 patients with COPD and group III included 20 healthy volunteers. The aim of this work was to study the relation between serum selenium level and whole blood GSH-Px activity and inflammation in bronchial asthma and COPD and if they have a correlation with the severity of the disease. All patients were subjected to history taking, clinical examination, ventilatory pulmonary function test and measurement of serum selenium level and whole blood GSH-Px activity. Serum selenium level and whole blood GSH-Px activity have a role in the pathogenesis of inflammation in bronchial asthma and COPD where they act against the oxidative stress. The reduction of serum selenium level and whole blood GSH-Px activity is correlated with the clinical and functional severity of the disease. Dietary supplementation with selenium and glutathione may have a role in the treatment of bronchial asthma and COPD