Central opiate mu-receptor-mediated suppression of tissue protein synthesis

1997 ◽  
Vol 273 (3) ◽  
pp. R920-R927 ◽  
Author(s):  
Y. Hashiguchi ◽  
P. E. Molina ◽  
S. Dorton ◽  
M. A. McNurlan ◽  
P. J. Garlick ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Respiratory Depression ◽  
Differential Sensitivity ◽  
Liver Protein ◽  
Intracerebroventricular Injection ◽  
Receptor Stimulation ◽  
Tissue Protein ◽  
Mu Receptor ◽  
Tissue Protein Synthesis ◽  
Dose Dependent

We determined the dose-dependent effects of central mu-opioid receptor stimulation on rates of tissue protein synthesis. Chronically catheterized conscious rats received an intracerebroventricular injection of [D-Ala2, N-Me-Phe4,Gly5-ol]enkephalin (DAGO, 0.5, 2, or 8 nmol/rat) or water (5 microliters) 45 min before determination of protein synthesis by the flooding dose technique. DAGO produced a significant decrease in tissue protein synthesis in liver (57%), spleen (54%), gut mucosa (36%), gut serosa (23%), kidney (48%), gastrocnemius (33%), and plantaris muscle (27%), but it did not alter rates of protein synthesis in the brain, heart, and soleus muscle. DAGO produced an acute dose-dependent respiratory depression 30 min after intracerebroventricular injection; this depression resulted in acidosis, hypoxia, and hypercapnia (pH 7.19 +/- 0.04, arterial partial O2, pressure 44.2 +/- 3.4 Torr, arterial O2 saturation 65.3 +/- 5.5%, and PCO2 66.3 +/- 4.4 Torr). Intracerebroventricular DAGO increased circulating levels of catecholamines, corticosterone, and growth hormone but did not alter those of insulin and insulin-like growth factor I. Significant positive correlations between protein synthesis and pH were observed in the tissues studied (i.e., liver protein synthesis vs. pH, P < 0.0001, r = 0.902; gastrocnemius protein synthesis vs. pH, P < 0.0001, r = 0.830). Our results indicate that mu-receptor stimulation inhibits tissue protein synthesis, and this effect appears to be secondary to respiratory depression and the resulting acidosis and/or hypoxia. Furthermore, our findings suggest differential sensitivity in tissue response to alterations in pH, hypoxia, and stress hormone elevation.

scholarly journals Acute IGF-I infusion stimulates protein synthesis in skeletal muscle and other tissues of neonatal pigs

2002 ◽  
Vol 283 (4) ◽  
pp. E638-E647 ◽  
Author(s):  
Teresa A. Davis ◽  
Marta L. Fiorotto ◽  
Douglas G. Burrin ◽  
Rhonda C. Vann ◽  
Peter J. Reeds ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Cardiac Muscle ◽  
Liver Protein ◽  
Tissue Protein ◽  
Neonatal Pigs ◽  
Igf I ◽  
Tissue Protein Synthesis ◽  
Insulin Replacement

Studies have shown that protein synthesis in skeletal muscle of neonatal pigs is uniquely sensitive to a physiological rise in both insulin and amino acids. Protein synthesis in cardiac muscle, skin, and spleen is responsive to insulin but not amino acid stimulation, whereas in the liver, protein synthesis responds to amino acids but not insulin. To determine the response of protein synthesis to insulin-like growth factor I (IGF-I) in this model, overnight-fasted 7- and 26-day-old pigs were infused with IGF-I (0, 20, or 50 μg · kg−1 · h−1) to achieve levels within the physiological range, while amino acids and glucose were clamped at fasting levels. Because IGF-I infusion lowers circulating insulin levels, an additional group of high-dose IGF-I-infused pigs was also provided replacement insulin (10 ng · kg−0.66 · min−1). Tissue protein synthesis was measured using a flooding dose ofl-[4-3H]phenylalanine. In 7-day-old pigs, low-dose IGF-I increased protein synthesis by 25–60% in various skeletal muscles as well as in cardiac muscle (+38%), skin (+24%), and spleen (+32%). The higher dose of IGF-I elicited no further increase in protein synthesis above that found with the low IGF-I dose. Insulin replacement did not alter the response of protein synthesis to IGF-I in any tissue. The IGF-I-induced increases in tissue protein synthesis decreased with development. IGF-I infusion, with or without insulin replacement, had no effect on protein synthesis in liver, jejunum, pancreas, or kidney. Thus the magnitude, tissue specificity, and developmental change in the response of protein synthesis to acute physiological increases in plasma IGF-I are similar to those previously observed for insulin. This study provides in vivo data indicating that circulating IGF-I and insulin act on the same signaling components to stimulate protein synthesis and that this response is highly sensitive to stimulation in skeletal muscle of the neonate.

Central effects of morphine and morphine-6-glucuronide on tissue protein synthesis

1996 ◽  
Vol 271 (3) ◽  
pp. R619-R625 ◽  
Author(s):  
Y. Hashiguchi ◽  
P. E. Molina ◽  
V. R. Preedy ◽  
P. H. Sugden ◽  
M. A. McNurlan ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Fold Increase ◽  
Potential Contribution ◽  
Intracerebroventricular Injection ◽  
Plasma Epinephrine ◽  
Tissue Protein ◽  
Central Effects ◽  
Arterial Ph ◽  
Tissue Protein Synthesis ◽  
The Brain

The central and peripheral effects of morphine sulfate (Mor) and morphine-6-glucuronide (M6G) on the fractional rates of tissue protein synthesis (kappa s) were determined. We determined ks in conscious rats 2 h after intracerebroventricular injection of Mor (80 micrograms/rat), M6G (1 microgram/rat), or H2O (5 microliters). Intracerebroventricular Mor and M6G administration decreased ks in the liver by 19 and 18% spleen by 19 and 17%, and gastrocnemius by 18 and 17%, respectively. Intravenous injection of Mor (8 mg/kg) or M6G (0.4 mg/kg) did not affect ks in any of the tissues studied. Intracerebroventricular Mor and M6G resulted in an equivalent 10- to 15-fold increase in plasma epinephrine, 2- to 3-fold increase in norepinephrine, and 80-90% increase in corticosterone, with no change in insulin levels. Intracerebroventricular Mor produced a significant 30% decrease in arterial partial O2 pressure (PaO2) and no significant changes in arterial pH and arterial partial CO2 pressure (PacO2). Intracerebroventricular M6G decreased PaO2 (40%) and pH (from 7.44 +/- 0.01 to 7.34 +/- 0.02) and increased Paco2 (36%). The potential contribution of hypoxia to the opiate-induced decrease in ks was assessed in an additional set of rats exposed to 5% O2-95% N2. One or 2 h of hypoxia decreased protein synthesis in the brain by 47 and 56%, liver by 69 and 69%, and skeletal muscle by 51 and 52%, respectively. Our results indicate that Mor and M6G suppress tissue protein synthesis through central mechanisms, most likely mediated by opiate-induced respiratory depression in association with neural and hormonal alterations.

scholarly journals Maternal protein reserves and their influence on lactational performance in rats 4. Tissue protein synthesis and turnover associated with mobilization of maternal protein

1994 ◽  
Vol 72 (6) ◽  
pp. 831-844 ◽  
Author(s):  
A.P. Pine ◽  
N.S. Jessop ◽  
G.F. Allan ◽  
J.D. Oldham
Keyword(s):  
Protein Synthesis ◽  
Dietary Protein ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Protein Restriction ◽  
Synthesis Rate ◽  
Liver Protein ◽  
Tissue Protein ◽  
Stage Of Lactation ◽  
Tissue Protein Synthesis

The present study was undertaken to investigate the changes in muscle protein turnover involved in the rapid mobilization of protein in rats subjected to severe protein restriction during lactation. Estimates of mammary gland and liver protein synthesis were also made during lactation. Multiparous female Sprague-Dawley rats, caged individually following mating, were offered a high-protein diet (H; 215 g crude protein (N - 6·25; CP)/kg dry matter (DM)) ad lib. until parturition. Following parturition, half the females continued to receive diet H, whilst the remainder were offered a diet low in protein (L; 90 g CP/kg DM) ad lib. On days 2, 4, 8 and 12 of lactation, groups of females were used in the estimation of tissue protein synthesis (flooding dose of [3H]phenylalanine) immediately after a milk sample had been obtained. Rates of muscle protein synthesis were unchanged during lactation in group H. The feeding of diet L during lactation reduced the muscle protein synthesis on day 12 to rates that were lower than group H and also the rate on diet L on day 2 (P 0·01). However, this fall in muscle protein synthesis was not rapid and muscle fractional synthesis rate (FSR) was different from group H only from day 8 (P 0·05). Estimated rates of mammary protein synthesis appeared to be generally unchanged by dietary treatment or stage of lactation. Liver FSR was also unchanged by dietary protein supply or stage of lactation. The effect of dietary protein restriction on liver size and protein content during lactation influenced liver absolute synthesis rate (ASR), and on days 8 and 12 of lactation liver ASR was lower in group L than in group H (P 0·001). The loss of muscle protein in rats fed on diet L during lactation (133 mg) occurred mainly between days 2 and 8 of lactation and was primarily associated with a dramatic increase in degradation (13·0% per d), with the decline in synthesis having a much smaller role. A decline in muscle protein degradation during the latter half of lactation was part of the mechanism that prevented excessive muscle protein catabolism. It is thought that the estimation of mammary protein synthesis in the present study was impaired by the milk sampling procedure previously used.

The Effect of Refeeding on Tissue Protein Synthesis in Rainbow Trout

1988 ◽  
Vol 61 (5) ◽  
pp. 429-441 ◽  
Author(s):  
D. N. McMillan ◽  
D. F. Houlihan
Keyword(s):  
Protein Synthesis ◽  
Rainbow Trout ◽  
Tissue Protein ◽  
Tissue Protein Synthesis

scholarly journals Dietary Ornithine Affects the Tissue Protein Synthesis Rate in Young Rats

2012 ◽  
Vol 58 (4) ◽  
pp. 297-302 ◽  
Author(s):  
Kazuyo TUJIOKA ◽  
Takashi YAMADA ◽  
Mami AOKI ◽  
Koji MORISHITA ◽  
Kazutoshi HAYASE ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Synthesis Rate ◽  
Protein Synthesis Rate ◽  
Tissue Protein ◽  
Young Rats ◽  
Tissue Protein Synthesis

Effects of the Fusarium toxin deoxynivalenol on tissue protein synthesis in pigs

2006 ◽  
Vol 165 (3) ◽  
pp. 297-311 ◽  
Author(s):  
S DANICKE ◽  
T GOYARTS ◽  
S DOLL ◽  
N GROVE ◽  
M SPOLDERS ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Tissue Protein ◽  
Fusarium Toxin ◽  
Tissue Protein Synthesis

Methionine Flux and Tissue Protein Synthesis in Lactating and Dry Goats

1990 ◽  
Vol 120 (9) ◽  
pp. 1006-1015 ◽  
Author(s):  
Claude Champredon ◽  
Elisabeth Debras ◽  
Philippe Patureau Mirand ◽  
Maurice Arnal
Keyword(s):  
Protein Synthesis ◽  
Tissue Protein ◽  
Tissue Protein Synthesis
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