Variations of 3-Methylhistidine in Blood of Dairy Cows

Abstract

Blood plasma 3-methylhistidine, in comparison with other blood variables, has been measured in high-yielding dairy cows with relation to energy and protein supply. Circulating 3-methylhistidine markedly increased to 1 wk after calving, then continuously decreased to 5 wk postpartum to lower than during the last 2 wk of pregnancy. In experiments 36 d after calving, circulating 3-methylhistidine did not change during 24 h despite marked variations of food intake. Peak 3-methylhistidine immediately after parturition coincided with relatively low insulin, thyroxine, triiodothyronine, glucose, protein, and urea with elevated concentrations of nonesterified fatty acids and with greatest estimated energy and protein deficiencies. However, during the ensuing period to 12 wk of lactation, circulating 3-methylhistidine was not closely related to these measures nor to creatinine, beta-hydroxybutyrate, and milk production, but relationships to milk protein yield were close. The postparturient increase of 3-methylhistidine may have been a consequence of enhanced breakdown of skeletal muscle and uterine smooth muscle or another pool with a transiently enhanced turnover rate. Variations of plasma 3-methylhistidine were associated only in part with estimated negative energy and protein balances and corresponding endocrine and metabolic adaptations.

Effects of high ambient temperature and restricted feed intake on urinary and plasma 3‐methylhistidine in lactating Holstein cows

“…(1996) revealed that the concentration of plasma 3MH is an index of myofibrillar protein degradation in goat. In addition, the concentration of plasma 3MH has been used as an index of myofibrillar protein degradation in dairy cows (Blum et al . 1985), mouse (Yoshizawa et al .…”

“…1993). Blum et al . (1985) also reported that an increase of plasma 3MH concentrations of dairy cows after parturition coincided with greatest estimated energy and protein deficiencies.…”

Metabolic, Enzymatic and Endocrine Status in High‐Yielding Dairy Cows – Part 2

“…Because there were farm differences, differences in feeding probably contributed to differences in AAN concentration, and increased protein intakes during lactation compared with the dry period possibly led to the post‐parturient rise in AAN. The breakdown of skeletal muscle and of smooth muscles (for example of the involuting uterus), resulting in a greater availability of amino acids for milk synthesis, has been confirmed (Reid et al., 1986) and probably contributed to a marked transient rise in plasma 3‐methylhistidine concentrations in early lactation (Blum et al., 1985b). Under conditions of normal liver and kidney function, plasma urea concentrations are well known to be influenced by protein and energy intake (Oltner and Wiktorsson, 1983; Clément et al., 1991).…”

Metabolismo oxidativo e perfil bioquímico de ovelhas Santa Inês no período periparto: efeito da suplementação com vitamina E

“…Uma fonte principal de proteína são os aminoácidos mobilizados dos músculos esqueléticos, embora a involução uterina possa ter sua contribuição (BLUM et al, 1985;BELL et al, 2000). Em vacas leiteiras, observou-se que a creatinina plasmática e o diâmetro muscular diminuíram uma semana antes do parto até quatro semanas após o parto, desta forma o autor supôs que a diminuição da creatinina observada na gestação, e o pico no final da mesma ocorre devido a mobilização de proteínas.…”

“…Os teores de creatinina aumentam à medida que ocorre a diminuição da taxa de filtração glomerular. Teores diminuídos de creatinina podem ser encontrados em condições de significativa redução na massa muscular, à mobilização de proteína é um dos eventos envolvidos no mecanismo de lactogênese, cuja fonte principal de proteína são os aminoácidos mobilizados dos músculos esqueléticos, embora a involução uterina também possa contribuir neste sentido (BLUM et al, 1985;BELL et al, 2000 O ácido úrico é considerado um antioxidante não-enzimático que atua formando complexos com o cobre prevenindo a oxidação de substâncias antioxidantes como a vitamina C. A concentração sérica de ácido úrico não apresentou diferença entre os tratamentos em P1 e P2, não tendo a aplicação da vitamina E influenciado nesta variável.…”