Pravastatin Protection from Cold Stress in Myocardium of Rats.

Abstract

SUMMARYThe aim of this research was to evaluate the possible protective effect of pravastatin on ultrastructural alterations induced by cold stress in the myocardium of rats.Sixteen EPM-Wistar rats (Rattus norvegicus albinus) were used and distributed into four groups: 1) control; 2) pravastatin; 3) cold stress, and 4) pravastatin + cold stress. A daily oral dose of 10 mg/kg of weight of pravastatin was administered to each rat in groups 2 and 4 for 15 days. The stress induced by cold was obtained by keeping the group 3 and 4 rats in a freezer at -8°C for 4 hours. The animals were killed and the heart and fragments of the left ventricles (LV) were removed and processed prior to conducting electron microscopic analysis.The ultrastructural alterations in cardiomyocytes were quantified through the number of mitochondrial cristae pattern (cristalysis). The group subjected only to cold stress showed a significant increase in cristalysis (391.9) when compared with control group (42.0). In the cold stress and pravastatin pretreatment group, a statistically significant (96.9)*, P<0.05 cristalysis reduction was observed when compared with cold stress group. The mitochondrial cristalysis profiles of the control and pravastatin groups were 42.0 and 65.7, respectively.Cold stress induced a significant increase in the rate of mitochondrial cristalysis. In the group that received pravastatin and was exposed to cold stress, the drug protected the LV cardiomyocytes. This fact was confirmed by a reduction mitochondrial cristalysis pattern. (Jpn Heart J 2003; 44: 243-255)

Fluoxetine effects on mitochondrial ultrastructure of right ventricle in rats exposed to cold stress

“…This autoimmune phenomenon is of unique relevance during cardiac operations when hypothermic cardiopulmonary bypass and cardioplegia are instituted [24]. The results of this study indicate the cold stress exposure as a protocol able to induce cardiac cells impairment, which is supported by previous investigations regarding cardiac cells protection [12][13][14][15][16][17]. Taken together, our results indicate a possible way to prevent or reduce the cardiac cell damage caused by the cold exposure during heart surgery.…”

“…Many drugs were tested to evaluate their effects on myocardium tissue of animals exposed to cold stress [3,[12][13][14][15][16][17]. In the 70 years Elonen [18] indicated that antidepressive drugs have high afinity with myocardial tissue due their high solubility in Comparison among control (CON), fluoxetine preadministration (FLU), induced hypothermic (IH) and IH with fluoxetine pre-administration (IHF) were performed.…”

Electric Countershock and Cold Stress Effects on Liver and Adrenal Gland

“…The temperature was controlled by the refrigerated compartment. No rats died during the induced hypothermia procedure 6–8…”

“…Exposure to low temperatures is considered to be an important stressing physical agent 4,5. Previous studies have reported that acute exposure to cold stress can damage heart tissue6 and cause lipid depletion in the adrenal gland and glycogen depletion in the liver,6–8 thus suggesting that sympathetic activity and oxidative stress are the sources of these injuries.…”

Intra-accumbal and Peripheral administration of nicotine reduces the side-effects of Inescapable Stress

“…Nicotine is a robust base, which rapidly absorbed crossways respiratory tract, skin, and oral mucosa and spreads the brain through a vein spreading in 8 seconds (Benowitz et al, 1991). Furthermore, nicotine is the most psychoactive complexes in tobacco (BLISS and AILION, 1969;Betz, 1990;Bidzseranova et al, 1992;Blokland et al, 1999) and its pharmacological effects are due to encouraging the release of numerous neurotransmitters (Bombig et al, 2003). It has been demonstrated that smoking decreases anxiety due to nicotine withdrawal (Bon and Garthwaite, 2003).…”