Efeitos da suplementação de creatina e do treinamento de potência sobre a performance e a massa corporal magra de ratos

Metabolic parameters in rats receiving different levels of oral glycerol supplementation

The use of glycerol in the diets for animals is of interest because it is a residue of biodiesel production and rich in energy. Thus, this study aimed to evaluate metabolic and physiological parameters of rats receiving supplemental pure glycerol by gavage. We used 30 Wistar rats (initial weight 202.7 ± 29.98 g) receiving 0 (control/saline), 200, 400, 800 and 1600 mg glycerol/kg of body weight (bidistilled glycerine, 99.85% glycerol) beside food and water ad libitum for 28 days. We used a completely randomised design with five treatments and six replicates. At the end of the experiment, the animals were killed, and the results showed that there was no change (p > 0.05) in the intake and excretion of water, the average daily weight gain, dry matter, ash and crude protein in the carcass or plasma triacylglycerols. There was a beneficial effect (p < 0.05) up to a dose of 800 mg/kg glycerol on feed intake, percentage of carcass fat, plasma levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), high-density lipoprotein (HDLc) and low-/very low-density lipoprotein (LDLc + VLDLc). The levels of total cholesterol and glucose were increased with up to a dose of 800 mg/kg glycerol (but remained within the normal range); they were reduced with the dose of 1600 mg/kg. The total leucocyte count tended to be reduced, although it was within the reference values for rats. There were no renal or pancreatic lesions. In conclusion, glycerol presented as a safe supplement at the studied doses, even having some beneficial effects in a dose-dependent manner in rats.

Histomorphometric analysis of the effects of creatine on rat myometrium

OBJECTIVE

To analyze the myometrial thickness of rats subjected to creatine (Cr) ingestion.

STUDY DESIGN

A total of 14 rats was equally divided into the control group (ConGr) receiving 1 ml potable water and the creatine group (CrGr) subjected to the ingestion of 1.6 g/kg Cr diluted in 1 ml potable water. At the end of 8 weeks, the animals were anesthetized (xylazine and ketamine) and sacrificed, the uteri and ovaries stained with hematoxylin and eosin, the thickness of both the myometrium and the epithelium measured and the follicles counted.

RESULTS

Analysis revealed a significant increase in thickness of the myometrium in the CrGr (272.26 ± 66.71μm) contrasted with that from the ConGr (160.76 ± 35.65μm), CrGr > ConGr (p < 0001).

CONCLUSION

Our data suggest that Cr changed myometrial morphology in rats by enhancing myometrial thickness, but its action mechanism in the smooth muscle is still unclear.