EFFECTS OF LOW CALCIUM AND LOW PHOSPHORUS DIETS ON THE DUODENAL ABSORPTION OF CALCIUM IN BETAMETHASONE-TREATED CHICKS

1978 ◽  
Vol 78 (2) ◽  
pp. 255-260 ◽  
Author(s):  
J. FOX ◽  
A. D. CARE ◽  
J. BLAHOS
Keyword(s):  
Growth Rate ◽  
Oral Administration ◽  
Low Calcium ◽  
Low Phosphorus ◽  
Treatment Administration ◽  
Loop Technique ◽  
Normal Calcium ◽  
Daily Oral Administration

SUMMARY The effect of oral administration of betamethasone (25 μg kg−1 day−1) on the duodenal absorption of calcium has been studied in chicks using the ligated loop technique in vivo. The chicks were fed normal calcium, normal phosphorus (NCaNP), low calcium, normal phosphorus (LCaNP) or normal calcium, low phosphorus (NCaLP) diets. Daily oral administration of betamethasone for 2–3 weeks markedly reduced the absorption of calcium in chicks fed the NCaNP diet, but did not significantly affect the adaptation in absorption when the NCaLP or LCaNP diets were fed for the same period of time. In one group of chicks, betamethasone was administered daily for 10 days before the birds were transferred to the NCaLP or LCaNP diets. Adaptation was again unaffected by betamethasone treatment. Administration of betamethasone caused a marked retardation in growth-rate, hypercalcaemia and an increased percentage of ash in the tibiae.

STIMULATION BY LOW PHOSPHORUS AND LOW CALCIUM DIETS OF DUODENAL ABSORPTION OF PHOSPHATE IN BETAMETHASONE-TREATED CHICKS

1981 ◽  
Vol 88 (1) ◽  
pp. 147-153 ◽  
Author(s):  
J. FOX ◽  
N. W. BUNNETT ◽  
A. R. FARRAR ◽  
A. D. CARE
Keyword(s):  
Oral Administration ◽  
Inhibitory Effect ◽  
Lower Weight ◽  
Low Calcium ◽  
Low Phosphorus ◽  
Loop Technique ◽  
Reduced Rate ◽  
Normal Calcium ◽  
Daily Oral Administration

Although the inhibitory effect of glucocorticoids on the intestinal absorption of calcium is well recognized, their effect on the absorption of phosphate is less well documented. We studied the effect of the oral administration of betamethasone (BM; 25 μg/kg per day) on the duodenal absorption of phosphate in chicks fed normal calcium, normal phosphorus (NCaNP), normal calcium, low phosphorus (NCaLP) or low calcium, normal phosphorus (LCaNP) diets using the ligated loop technique in vivo. The daily oral administration of BM for 8 days significantly reduced the absorption of phosphate in chicks fed the NCaNP diet (21% decrease) but had less effect in chicks fed the NCaLP (14% decrease) or LCaNP (9% decrease) diets in which birds the absorption of phosphate was significantly raised (49 and 87% respectively). In one group of chicks, BM was administered for 9 days before the birds were transferred to the NCaLP or LCaNP diets. Adaptation was again unaffected by the treatment. Thirty-four per cent of the absorbed phosphate was retained in the duodenal tissue. Treatment with BM reduced the amount retained but this may have been caused by the lower weight of the duodenal segment in these chicks as BM administration markedly reduced growth rate. We have concluded that the duodenal absorption of phosphate in the chick can be inhibited by treatment with BM, although this may be secondary to the reduced rate of growth, but the increase in the absorption of phosphate caused by feeding NCaLP or LCaNP diets was unaffected by the steroid.

scholarly journals Hypocalcin from Stannius corpuscles inhibits gill calcium uptake in trout

1988 ◽  
Vol 254 (6) ◽  
pp. R891-R896 ◽  
Author(s):  
F. P. Lafeber ◽  
G. Flik ◽  
S. E. Wendelaar Bonga ◽  
S. F. Perry
Keyword(s):  
Rainbow Trout ◽  
Calcium Uptake ◽  
Inhibitory Effect ◽  
Whole Body ◽  
Transepithelial Potential ◽  
Low Calcium ◽  
Stannius Corpuscles ◽  
Normal Calcium

Bidirectional whole body flux and branchial Ca2+ influx were measured in freshwater rainbow trout. Intra-arterial injections of homogenates of Stannius corpuscles (CS) as well as of a 54-kDa isolated product (hypocalcin) exerted an inhibitory effect on whole body Ca2+ influx, but did not effect Ca2+ efflux. Hypocalcin was more effective in reducing Ca2+ influx in trout acclimated to low-calcium freshwater than in fish from normal-calcium water. We conclude that the isolated product (hypocalcin) represents the hypocalcemic principle of the CS. Similar doses of hypocalcin caused quantitatively similar decreases in Ca2+ influx in vivo and in the isolated perfused head preparation. This indicates that the gills form the principle target for hypocalcin in trout. The branchial transepithelial potential did not change during hormone treatments. Possible mechanisms of hypocalcin action are suggested.

Orally Active Inhibitors of the Imatinib Resistant Bcr-Abl Mutant T315I.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2180-2180 ◽  
Author(s):  
William C. Shakespeare ◽  
Frank Wang ◽  
Qihong Xu ◽  
Xiaotian Zhu ◽  
Narayana Narasimham ◽  
...  
Keyword(s):  
Oral Administration ◽  
Cellular Proliferation ◽  
Kinase Inhibitor ◽  
Tumor Regression ◽  
Point Mutations ◽  
Drug Binding ◽  
Separate Model ◽  
Daily Oral Administration

Abstract Resistance to the Bcr-Abl kinase inhibitor imatinib in patients with chronic myeloid leukemia (CML) is associated with emergence of Bcr-Abl point mutations that preclude effective drug binding. Although most mutants are effectively inhibited with the second generation inhibitors dasatinib and nilotinib, neither compound inhibits the T315I mutant which represents ~ 25% of all clinically observed mutants. Through our program of structure-guided design, we have identified a series of compounds that inhibit the T315I mutant of Bcr-Abl both in vitro and in vivo. AP24534, a representative member of this new series, inhibited the kinase activity of both the wild-type enzyme and the T315I point mutant with IC50s of 3 and 31 nM respectively, and inhibited the proliferation of their respective BaF3-derived cell lines with IC50s of 2 and 14 nM. Additionally, AP24534 inhibited the proliferation of BaF3 cells expressing the clinically relevant mutants Y253F, E255K, H396P, or M351T with IC50s of 2, 7, 1, and 1 nM respectively. Inhibition of cellular proliferation directly correlated with decreased cellular phosphorylation of Bcr-Abl. Daily oral administration of AP24534 to mice bearing subcutaneous xenografts of Bcr-Abl-T315I-expressing BaF3 cells elicited dose-dependent tumor shrinkage, with complete tumor regression observed at the highest doses. In a separate model, daily oral administration of AP24534 significantly prolonged the survival of mice injected intravenously with these cells, at doses ranging from 5–30 mg/kg. These data indicate that this class of inhibitors has the potential to address CML refractory to current targeted agents.

Endocrinological effects of single daily ketoconazole administration in male beagle dogs

1984 ◽  
Vol 107 (2) ◽  
pp. 275-281 ◽  
Author(s):  
Roland De Coster ◽  
Dominiek Beerens ◽  
Jef Dom ◽  
Gustaaf Willemsens
Keyword(s):  
Oral Administration ◽  
Plasma Cortisol ◽  
Plasma Concentrations ◽  
The Other ◽  
Plasma Testosterone ◽  
Beagle Dogs ◽  
Basal Cortisol ◽  
High Doses ◽  
Daily Oral Administration

Abstract. Some endocrinological effects of single daily oral administration of 150 mg ketoconazole for 15 days were investigated in 4 male beagle dogs. Plasma testosterone fell markedly within 3–4 h and then progressively returned to control concentrations by 10 h after drug administration. On the other hand, plasma 17α-hydroxyprogesterone, progesterone and 17α,20α-dihydroxyprogesterone increased within 3–10 h before returning to basal values after 24 h. Plasma LH did not rise significantly though some high individual levels were noted. Plasma cortisol and oestradiol-17α levels were not significantly modified by the treatment. These results confirm that a high therapeutic dose of ketoconazole, given orally once a day, transiently inhibits in vivo the 17–20 lyase enzyme of the testis, without modifying basal cortisol and oestradiol-17β plasma concentrations and that enzymatic inhibition still occurs after daily treatment for up to 2 weeks but remains transient and parallels the resorption profile of the drug so that normal plasma testosterone levels are observed from 10 to 24 h after drug intake. However, permanent inhibition of androgen biosynthesis might be obtained by the administration of high doses of ketoconazole given several times a day.

Metabolism in Vitro of 25-Hydroxycholecalciferol in Chicks Fed on Phosphorus-Deficient Diets

1978 ◽  
Vol 54 (2) ◽  
pp. 197-200 ◽  
Author(s):  
R. Swaminathan ◽  
Barbara A. Sommerville ◽  
A. D. Care
Keyword(s):  
Calcium Absorption ◽  
Plasma Calcium ◽  
Hydroxylase Activity ◽  
High Phosphorus ◽  
Phosphorus Deprivation ◽  
Low Phosphorus ◽  
Loop Technique ◽  
25 Hydroxycholecalciferol

1. Three groups of 10-days-old chicks were fed on one of three diets having phosphorus contents of 0·08 mol/kg, 0·14 mol/kg or 0·21 mol/kg. Ten days later duodenal calcium absorption by the ligated loop technique in vivo, and plasma calcium and phosphorus concentrations, were measured. In addition the metabolism in vitro of 25-hydroxycholecalciferol [25-(OH)D3] by kidney homogenates was studied. 2. In the low phosphorus group (0·08 mol/kg) calcium absorption and the activity of 25-(OH)D3-1-hydroxylase were significantly higher than those of the high phosphorus group (0·21 mol/kg). However, in the medium phosphorus group (0·14 mol/kg), calcium absorption was significantly higher although the activity of 25-(OH)D3-1-hydroxylase was not significantly higher when compared with the high phosphorus group (0·21 mol/kg). 3. It is concluded that in phosphorus deprivation, unlike in calcium deprivation, a diet very low in phosphorus is required to stimulate the renal 25-(OH)D3-1-hydroxylase activity.

THE ROLE OF THE PARATHYROID GLANDS IN THE ABSORPTION OF CALCIUM FROM THE SMALL INTESTINE

1970 ◽  
Vol 47 (1) ◽  
pp. 65-72 ◽  
Author(s):  
M. WINTER ◽  
E. MORAVA ◽  
G. SIMON ◽  
J. SÓS
Keyword(s):  
Small Intestine ◽  
Calcium Absorption ◽  
Normal Diet ◽  
Calcium Excretion ◽  
Deficient Diet ◽  
High Calcium ◽  
Low Phosphorus ◽  
Loop Technique

SUMMARY The absorption of calcium from duodenal and jejunal segments of the small intestine was studied in rats using an in-vivo loop technique. Previous parathyroidectomy decreased calcium absorption from both segments in rats fed a normal diet. Reduced calcium transport was greater in rats fed a calcium-deficient diet after parathyroidectomy. The slower clearance of radioactive calcium from the lumen of the intestine was not due to increased endogenous calcium excretion. Thyroidectomy, either alone or combined with parathyroidectomy, decreased calcium absorption but the effect of thyroidectomy alone requires further study. The decrease in calcium absorption after removal of the parathyroids was minimal or absent when the animals were fed a high calcium, low phosphorus, vitamin D-deficient diet or fasted 48 hr. before the experiment.

The Filter Loop Technique as a Method of Measuring Platelet Aggregation in the Flowing Blood of the Rat; the Inhibitory Activity of 5-oxo-l-cyclopentene-l-heptanoic Acid (AY-16,804) on Platelet Aggregation

1973 ◽  
Vol 30 (01) ◽  
pp. 138-147 ◽  
Author(s):  
Christopher R. Muirhead
Keyword(s):  
Platelet Aggregation ◽  
Prostaglandin E1 ◽  
Suitable Model ◽  
Heptanoic Acid ◽  
Simple Method ◽  
Loop Technique ◽  
Flowing Blood ◽  
Filter Loop

SummaryThe filter loop technique which measures platelet aggregation in vivo in the flowing-blood of the rat was compared to the optical density technique of Born which is carried out in vitro with platelet rich plasma. Using these two experimental models the effect on platelet aggregation of three known inhibitors sulfinpyrazone, dipyridamole and prostaglandin E1, and a novel compound 5-oxo-l-cyclopentene-l-heptanoic acid (AY-16, 804) was determined.The effects on platelet aggregation of the known inhibitors were consistent with information in the literature. Prostaglandin E1 was the most potent inhibitor in both techniques; sulfinpyrazone inhibited aggregation in both models but was less potent than prostaglandin E1. AY-16, 804 exhibited activity in vitro and in vivo similar to that of sulfinpyrazone. Dipyridamole did not inhibit platelet aggregation in vivo and did not inhibit aggregation in vitro in concentrations at which it remained soluble.The filter loop technique is a suitable model for measuring platelet aggregation in the flowing blood of the rat. It is a relatively simple method of determining aggregation and easily adapted to other species.

A Comparative Pharmacokinetic Profile of Trahydropalmatine After Oral Administration of its Monomer, Rhizoma Corydalis Alkaloid Extracts and Tong-Bi-Si-Wei-Fang to Rats

2019 ◽  
Vol 15 (4) ◽  
pp. 338-345
Author(s):  
Lijun Ni ◽  
Lu Ding ◽  
Liguo Zhang ◽  
Shaorong Luan
Keyword(s):  
Oral Administration ◽  
Panax Notoginseng ◽  
Pharmacokinetic Profile ◽  
Apparent Volume ◽  
Bone Diseases ◽  
Glycyrrhiza Uralensis ◽  
Pharmacokinetic Property ◽  
Time Curve ◽  
Concentration Time

Background: Tong-Bi-Si-Wei-Fang (TBSWF) is a candidate formula of Traditional Chinese Medicine (TCM) for treating rheumatoid bone diseases, which is composed of rhizoma corydalis alkaloids, saponins of glycyrrhiza uralensis and panax notoginseng, flavonoids of rhizoma drynariae and glycyrrhiza uralensis. </P><P> Objective: Trahydropalmatine (THP), the main active ingredient of rhizoma corydalis alkaloids, was selected to study in vivo pharmacokinetics and druggability of TBSWF. Methods: The plasma concentration-time (C-T) profiles of THP and the pharmacokinetic property parameters after oral administration of THP monomer, extract of corydalis alkaloids (ECA) and TBSWF to rats, respectively were compared by a fully-validated HPLC method. Results: Compared to the THP monomer, the THP in TBSWF is absorbed faster, resides in the plasma longer and has a similar apparent volume of distribution Vz/F (10~20 L/kg). Compared to THP monomer and THP in TBSWF, the area under the concentration-time curve AUC 0-t of THP in ECA decreases two-third; Vz/F of THP in ECA (85.02 L/kg) is significantly higher than that of THP in TBSWF(p <0.05). Unlike THP monomer and THP in ECA, double peaks are observed in the C-T profile of THP after oral administration of TBSWF. THP in TBSWF exhibits slow release to a certain degree. Conclusion: The interactions among the ingredients of TBSWF promote the adsorption and prolong the residence time of THP in vivo, and provide an explanation for the advantages of TBSWF from the point of pharmacokinetics.

Lentiviral-Mediated Beclin-1 Overexpression Inhibits Cell Proliferation and Induces Autophagy of Human Esophageal Carcinoma Eca109 Cell Xenograft in Nude Mice

2020 ◽  
Vol 15 (1) ◽  
pp. 70-77
Author(s):  
Junhe Zhang ◽  
Weihua Dong
Keyword(s):  
Growth Rate ◽  
Cell Proliferation ◽  
Esophageal Carcinoma ◽  
Nude Mice ◽  
Beclin 1 ◽  
Control Group ◽  
Vector Group ◽  
Empty Vector ◽  
Empty Vector Group

Background: Esophageal carcinoma is one of the common malignant tumors in digestive tract. BECLIN-1 is a key gene that regulates autophagy, and its abnormal expression may be related with many human tumors. However, the mechanism of BECLIN-1 in esophageal carcinoma remains unknown. Objective: In this study, we explored the effect of BECLIN-1 overexpression on tumor growth in mice with esophageal carcinoma and its mechanism. Methods: Recombined lentiviral vector containing BECLIN-1 was used to transfect human esophageal carcinoma Eca109 cells and establish stable cell line. qRT-PCR was used to detect BECLIN-1 mRNA level in the transfected Eca109 cells, CCK-8 assay was used to detect cell proliferation. Beclin-1, P62 and LC3-II protein expression levels in Eca109 cells were detected using Western blot analysis. Subcutaneous xenograft nude mice model of human esophageal carcinoma was established, and the tumor growths in Beclin-1 group, control group and empty vector group were monitored. Beclin-1 protein expression in vivo was detected by immunohistochemistry. Results: Beclin-1 mRNA and protein were overexpressed in Eca109 cells. Compared with empty vector group, the growth rate of cells transfected with BECLIN-1 decreased significantly. Compared with the control group and empty vector group, the expression level of P62 protein in beclin-1 group was significantly decreased, while the expression level of LC3-II protein was significantly increased. The tumor growth rate in nude mice of Beclin-1 group was significantly lower than that of the control group and empty vector group, and Beclin-1 protein was mainly expressed in Beclin-1 group in vivo. Conclusion: BECLIN-1 can induce autophagy in esophageal carcinoma Eca109 cells, and it can significantly inhibit the growth of esophageal carcinoma.

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