Application of the slope‐ratio growth assay technique to estimate tryptophan availability in soybean meal fed to young rats

2019 ◽  
Vol 90 (9) ◽  
pp. 1270-1277 ◽  
Author(s):  
Hiroyuki Sato ◽  
Makoto Miura ◽  
Takeshi Fujieda ◽  
Masaaki Toyomizu
Keyword(s):  
Soybean Meal ◽  
Slope Ratio ◽  
Young Rats ◽  
Growth Assay ◽  
Assay Technique

Variation in lysine, threonine, and tryptophan availability in meat and bone meal as estimated by the slope‐ratio growth assay technique in growing rats

2020 ◽  
Vol 91 (1) ◽  
Author(s):  
Hiroyuki Sato ◽  
Makoto Miura ◽  
Takeshi Fujieda ◽  
Marcin Taciak ◽  
Motoi Kikusato ◽  
...  
Keyword(s):  
Slope Ratio ◽  
Meat And Bone Meal ◽  
Bone Meal ◽  
Growing Rats ◽  
Growth Assay ◽  
Assay Technique

scholarly journals Relative bioavailability of phosphorus in low-phytate soybean meal for broiler chicks

2003 ◽  
Vol 83 (1) ◽  
pp. 95-100 ◽  
Author(s):  
J. S. Sands ◽  
D. Ragland ◽  
J. R. Wilcox ◽  
O. Adeola
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Soybean Meal ◽  
Corn Starch ◽  
Body Weight Gain ◽  
Basal Diet ◽  
Relative Bioavailability ◽  
Response Criteria ◽  
Slope Ratio ◽  
Total P

A 14-d chick bioassay was conducted to estimate the relative bioavailability (RBV) of P in a low-phytate soybean meal (LPSBM) using slope-ratio techniques. A corn-soybean meal basal diet was formulated to supply total P and Ca at 3.3 and 10.5 g kg-1, respectively. Three reference diets were formulated by the addition of 0, 0.5 or 1.0 g kg-1 total P from monosodium phosphate (MSP). Four test diets were formulated by the addition of 0.5 or 1.0 g kg-1 total P from LPSBM or soybean meal (SBM). The additions of MSP, LPSBM, or SBM were made at the expense of corn starch. A diet consisting of the basal diet plus supplemental methionine, lysine, threonine and tryptophan was also included to confirm that response to diets containing LPSBM or SBM was not due to the higher concentration of amino acids in those diets. Each diet was randomly assigned to six replicate cages of four birds. Birds were fed from 1 to 3 wk of age. Body weight gain (P < 0.01) and feed intake (FI, P < 0.05) increased linearly as supplemental dietary P increased from 0 to 1.0 g kg-1 for chicks fed diets containing MSP or LPSBM. Chicks that received the basal P level had the lowest body weight gain and FI. No differences were observed between the basal diet and the amino-acid-supplemented basal diet in any of the response criteria measured indicating that the response to tests was due to the increasing levels of dietary P. Tibia mineral content (TMC) and tibia ash weight (ASH) increased linearly (P < 0.001) in response to supplemental P from MSP, LPSBM and SBM. The RBV for LPSBM and SBM using ASH as the response criteria were estimated at 52 ± 10% and 36 ± 8%, respectively. The RBV for LPSBM and SBM using TMC as the response criteria were estimated at 61 ± 9% and 39 ± 7% , respectively. The RBV of LPSBM was 12 to 16 percentage points higher than SBM depending on the response criteria used for estimating RBV. The results of this study clearly indicate that P from LPSBM is more bioavailable than P from SBM. Key words: Chicks, phosphorus, low-phytate soybean meal, bioavailability, slope-ratio

Effect of Calcium on the Growth and Differentiation of Cultured Rat Esophageal Epithelial Cells

1982 ◽  
Vol 40 ◽  
pp. 132-133
Author(s):  
W.T. Gunning ◽  
M.R. Marino ◽  
M.S. Babcock ◽  
G.D. Stoner
Keyword(s):  
Epithelial Cells ◽  
Cell Types ◽  
Replication Rate ◽  
Enzymatic Dissociation ◽  
Growth Assay ◽  
Epidermal Growth ◽  
Fetal Bovine ◽  
Esophageal Epithelial Cells ◽  
Cellular Replication

The role of calcium in modulating cellular replication and differentiation has been described for various cell types. In the present study, the effects of Ca++ on the growth and differentiation of cultured rat esophageal epithelial cells was investigated.Epithelial cells were isolated from esophagi taken from 8 week-old male CDF rats by the enzymatic dissociation method of Kaighn. The cells were cultured in PFMR-4 medium supplemented with 0.25 mg/ml dialyzed fetal bovine serum, 5 ng/ml epidermal growth factor, 10-6 M hydrocortisone 10-6 M phosphoethanolamine, 10-6 M ethanolamine, 5 pg/ml insulin, 5 ng/ml transferrin, 10 ng/ml cholera toxin and 50 ng/ml garamycin at 36.5°C in a humidified atmosphere of 3% CO2 in air. At weekly intervals, the cells were subcultured with a solution containing 1% polyvinylpyrrolidone, 0.01% EGTA, and 0.05% trypsin. After various passages, the replication rate of the cells in PFMR-4 medium containing from 10-6 M to 10-3 M Ca++ was determined using a clonal growth assay.

On the Fibrinolytic System in Aged Rats, and Its Reactivity to Endotoxin and Cytokines

1992 ◽  
Vol 67 (06) ◽  
pp. 697-701 ◽  
Author(s):  
J J Emeis ◽  
A Brouwer ◽  
R J Barelds ◽  
M A Horan ◽  
S K Durham ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Fibrinolytic System ◽  
Tissue Type ◽  
High Dose ◽  
Base Line ◽  
Aged Rats ◽  
Tissue Type Plasminogen Activator ◽  
Young Rats ◽  
Type Plasminogen Activator

SummaryAged rats are more susceptible to endotoxin-induced effects, including microthrombosis and platelet aggregation, than are young rats. To investigate whether changes in the fibrinolytic system might be involved, we investigated the fibrinolytic activity in plasma euglobulin fractions and tissues (lung and heart) of young (6-months old) and aged (24-months old) rats under baseline conditions and after challenge with endotoxin. Aged rats had lower plasma levels of tissue-type plasminogen activator (t-PA) and of urokinase-type PA (u-PA) activity. PA inhibitor (PAI) activity was higher in the plasma of aged rats, as was t-PA activity in lung and heart.Rats were treated with either a low dose (1 μg/kg) or a high dose (10 mg/kg) of endotoxin. Both treatments induced a transient phase of increased blood fibrinolytic activity, as evidenced by higher levels of tissue-type plasminogen activator (t-PA) activity and decreased levels of PA inhibitor (PAI) activity. Over time, the fibrinolytic activity decreased, probably due to increased levels of PA inhibitor.Both the early increase in t-PA activity, and the subsequent increase in PAI activity, were more pronounced in the aged rats, as compared with the younger rats, after the high dose of endotoxin. The aged rats also responded to an injection of interleukin-1β or tumor necrosis factor-α with a larger increase of PAI activity than did the younger rats.Together the data suggest that, compared to young rats, aged rats have a decreased base-line plasma fibrinolytic activity, while their fibrinolytic system is more responsive to challenge by endotoxin and cytokines.

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