Effects of dietary protein intake on muscle protein synthesis and degradation in rats with gentamicin-induced acute renal failure.
In the study presented here, the muscle protein synthesis and degradation in gentamicin-induced acute renal failure were examined in rats fed a low (7%)-, normal (22%)-, and high (35%)-isocaloric protein diet. Male Sprague-Dawley rats were fed equivalent amounts of these diets for 10 days and then received daily subcutaneous injections of either 1 mL of sterile isotonic saline or 100 mg/kg of gentamicin for 7 consecutive days. The rats were sacrificed the following day, and epitrochlearis muscles were obtained for measurement of protein turnover. The serum creatinine in each of the gentamicin-treated groups were significantly higher than that in the saline-treated controls but were no different from each other. Muscle protein synthesis (calculated from the incorporation of radiolabeled (U-14C) phenylalanine) was slightly but not significantly decreased in gentamicin-treated rats as compared with that of the corresponding saline controls in each of the dietary groups. Net protein degradation (the rate of tyrosine release into media) in the 7 and 22% gentamicin-treated groups was similar to that in the corresponding saline controls. In contrast, net protein degradation was significantly greater in the 35% gentamicin group of rats when compared with that in the 7 and 22% gentamicin groups and its own control. In the 7 and 22% saline- and gentamicin-treated protein groups, there was a reduction in net protein degradation in response to insulin. In contrast, the net protein degradation continued to remain significantly elevated in the 35% gentamicin-treated group, despite addition of insulin, when compared with that in the 7 and 22% gentamicin groups and its own control.(ABSTRACT TRUNCATED AT 250 WORDS)
Louisiana State University Medical Center, Department of Pediatrics, New Orleans 70112.
R
R
Baliga
S V
SV
Shah
D058186:Acute Kidney Injury / Q000139:chemically induced / Q000178:diet therapy / Q000378:metabolism*; D000818:Animals; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000009:adverse effects; D005839:Gentamicins; D008297:Male; D009124:Muscle Proteins / Q000096:biosynthesis* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D004044:Dietary Proteins; D005839:Gentamicins; D009124:Muscle Proteins