Muscle protein turnover in cattle of differing genetic backgrounds as measured by urinary N tau-methylhistidine excretion

Journal Article · Thu Dec 01 04:00:00 EST 1983 · J. Nutr.; (United States)

OSTI ID:6630742

McCarthy, F D; Bergen, W G; Hawkins, D R

N tau-methylhistidine (N tau MH) was used as an index for muscle protein degradation and this index was utilized to evaluate degradation rates in young growing cattle. Initially, two Charolais crossbred heifers, 12 months of age, were used to measure the recovery of radioactivity in the urine for a 120-hour period after intravenous injection of (/sup 14/C)N tau MH. Of the radioactivity injected into the animals, 89.7% was recovered after 120 hours. With rate and amount of clearance as the criteria, the excretion of N tau MH in urine appears to be a valid index of muscle protein degradation in cattle. Eight steers of two genetic types were used to evaluate the effect of frame size on turnover rates of muscle proteins with N tau MH as an index. Large frame cattle (LG) excreted more N tau MH per day throughout the trial. Total daily creatinine excretion was less for small frame (SM) cattle showing an increase with time in LG and SM cattle. N tau MH-to-creatinine ratios showed a decline with time. Fractional breakdown rates (FBR) and fractional synthesis rates (FSR) appeared to parallel each other with rates tending to decrease with age. No differences were observed between LG and SM cattle for FBR, FSR or fractional growth rate (FGR).

• Research Organization: Michigan State Univ., East Lansing
• OSTI ID: 6630742
• Journal Information: J. Nutr.; (United States), Journal Name: J. Nutr.; (United States) Vol. 113:12; ISSN JONUA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMAL GROWTH
ANIMALS
AZOLES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL MATERIALS
BIOLOGICAL WASTES
BODY FLUIDS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CATTLE
DOMESTIC ANIMALS
ELEMENTS
GROWTH
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HISTIDINE
IMIDAZOLES
INJECTION
INTAKE
INTRAVENOUS INJECTION
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MAMMALS
MATERIALS
MEASURING METHODS
METABOLISM
MUSCLES
NITROGEN
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PROTEINS
RADIOASSAY
REACTION KINETICS
RUMINANTS
TRACER TECHNIQUES
URINE
VERTEBRATES
WASTES