Cholesterol Metabolism and Vitamin B6. IV. Synthesis of Cholic Acid Conjugates in Vitamin B6-Deficient Rats

1971 ◽  
Vol 49 (9) ◽  
pp. 1026-1030 ◽  
Author(s):  
M. D. Avery ◽  
P. J. Lupien

The in vitro conjugation of labelled free cholic acid with glycine and taurine in the livers of vitamin B6-deficient and pair-fed rats has been investigated. It appears from these results that vitamin B6-deficiency stimulates this conjugation, and some evidence is given which suggests that vitamin B6 may be responsible for the lower capacity of conjugation observed in the liver of the pair-fed rat.


1955 ◽  
Vol 33 (1) ◽  
pp. 562-567
Author(s):  
John R. Beaton

Following earlier studies on carbohydrate metabolism in the vitamin-B6-deprived rat, in vitro investigations have been carried out. In all cases, comparisons were made between tissues from vitamin-B6-deprived and pair-fed control animals so that differences in the amount of food consumed would not affect the interpretation of experimental results. No significant difference was found in glucose utilization by muscle nor in liver cytochrome oxidase activity. Liver aldolase activity was significantly decreased and the activity of plasma alkaline phosphatase was significantly increased in the vitamin-B6-deprived rats. In vitamin-B6-deprived female rats, but not male rats, liver catalase activity was significantly increased. These results are discussed in the light of earlier observations indicating disturbances in carbohydrate metabolism in the vitamin-B6-deprived rat.



1954 ◽  
Vol 32 (6) ◽  
pp. 684-688 ◽  
Author(s):  
J. R. Beaton ◽  
M. E. Goodwin

The results of in vivo and in vitro studies on carbohydrate metabolism in the vitamin-B6-deprived rat are reported. All comparisons were made with pair-fed control animals. Within five days of vitamin B6 restriction, rats have significantly lowered fasting levels of blood sugar and liver glycogen. These abnormalities are more marked after 21 days of deprivation and are accompanied by significantly lowered fasting blood levels of pyruvic acid and lactic acid. The activity of lactic acid dehydrogenase, one enzyme involved in carbohydrate metabolism, was measured in vitro and found to be significantly depressed in the vitamin-B6-deprived rat. The conclusion is drawn that an abnormal metabolism of carbohydrate occurs in rats deprived of vitamin B6. This abnormality is evident early in the deprivation period.



1954 ◽  
Vol 32 (1) ◽  
pp. 684-688
Author(s):  
J. R. Beaton ◽  
M. E. Goodwin

The results of in vivo and in vitro studies on carbohydrate metabolism in the vitamin-B6-deprived rat are reported. All comparisons were made with pair-fed control animals. Within five days of vitamin B6 restriction, rats have significantly lowered fasting levels of blood sugar and liver glycogen. These abnormalities are more marked after 21 days of deprivation and are accompanied by significantly lowered fasting blood levels of pyruvic acid and lactic acid. The activity of lactic acid dehydrogenase, one enzyme involved in carbohydrate metabolism, was measured in vitro and found to be significantly depressed in the vitamin-B6-deprived rat. The conclusion is drawn that an abnormal metabolism of carbohydrate occurs in rats deprived of vitamin B6. This abnormality is evident early in the deprivation period.



1987 ◽  
Author(s):  
A M Randi ◽  
E Sacchi ◽  
M Cattaneo

It is known that mM concentrations of vitamin B6 inhibit human platelet aggregation and fibrin formation in vitro. There are very few and controversial data on the ex vivo effects of vitamin B6 on hemostatic parameters. We evaluated the effects of oral administration of vitamin B6 on bleeding time (BT), fibrin formation, platelet aggregation (PA) and the release reaction (RR). Vitamin B6 300 mg/day p.o., was given to 18 healthy volunteers (8 M, 10 F, aged 23-35) for 8 days. BT was measured before the first dose (Baseline), 2 hr after the first (Day 1) and the last dose (Day 8). In 7 subjects BT was measured also 7 days after the suspension of the drug (Day 15). Before and 2 hr after the first dose, prothrombin time (PT), partial thromboplastin time (PTT), thrombin time (TT), PA and the RR induced by different concentrations of ADP, PAF-acether, collagen (coll), epinephrine (epi), arachidonate (AA) were studied. BT was significantly prolonged after vitamin B6 administration, and returned to baseline values 7 days after suspension of the drug. PA and the RR induced by 1 uM ADP, 1 ug/ml coll or 5 uM epi were significantly inhibited 2 hours after vitamin B6 administration. Vitamin B6, however, did not affect PA or the RR induced by 0.2-2 uM PAF-acether, 2 uM ADP, 1 mM AA, 2 ug/ml coll, nor did it affect PT, PTT or TT. These data show that orally administered vitamin B impairs primary hemostasis, but does not affect fibrin 6 formation, as measured with standard coagulation tests.



1955 ◽  
Vol 33 (4) ◽  
pp. 562-567
Author(s):  
John R. Beaton

Following earlier studies on carbohydrate metabolism in the vitamin-B6-deprived rat, in vitro investigations have been carried out. In all cases, comparisons were made between tissues from vitamin-B6-deprived and pair-fed control animals so that differences in the amount of food consumed would not affect the interpretation of experimental results. No significant difference was found in glucose utilization by muscle nor in liver cytochrome oxidase activity. Liver aldolase activity was significantly decreased and the activity of plasma alkaline phosphatase was significantly increased in the vitamin-B6-deprived rats. In vitamin-B6-deprived female rats, but not male rats, liver catalase activity was significantly increased. These results are discussed in the light of earlier observations indicating disturbances in carbohydrate metabolism in the vitamin-B6-deprived rat.



1991 ◽  
Vol 260 (3) ◽  
pp. G457-G463 ◽  
Author(s):  
M. Moreto ◽  
C. Amat ◽  
A. Puchal ◽  
R. K. Buddington ◽  
J. M. Planas

We examined the characteristics of amino acid and sugar absorption by the proximal cecum (PC) of chickens during posthatch development. Rates of absorption of L-proline (Pro) and alpha-methyl-D-glucoside (MG) were measured at 2 days, 5 wk, and 13 wk after hatch with an in vitro everted-sleeve method. For each age, pieces of PC and midjejunum were incubated in solutions containing 0.1-50 mM Pro or MG, and the active and passive components of Pro and MG absorption were determined. Five conclusions may be stated. 1) There are two carrier-mediated transport systems for Pro in the PC: a higher capacity Na(+)-dependent system (Vmax between 1.6 and 3.2 nmol.mg-1.min-1), and a lower capacity Na(+)-independent system (Vmax 0.3-0.8 nmol.mg-1.min-1). 2) Whereas both Pro transport systems are present in the PC at 5 and 13 wk, only the Na(+)-dependent system was found at 2 days. Although rates of transport per milligram tissue by the Na(+)-dependent system fell during development, when rates were normalized to nominal surface area, Vmax was significantly higher in the 5-wk-old group than in the other groups. 3) MG transport is by a Na(+)-dependent system. Vmax values (nmol.mg-1.min-1) were 0.32 (2 days), less than 0.43 (5 wk), and = 0.55 (13 wk). These differences were not affected by normalization to surface area. 4) Because at physiological concentrations passive influx of Pro and MG would be negligible, absorption of amino acids and sugars by the PC would be dependent on the presence of carrier-mediated systems.(ABSTRACT TRUNCATED AT 250 WORDS)



2009 ◽  
Vol 25 (2) ◽  
pp. 161-177 ◽  
Author(s):  
Bhavesh D. Kevadiya ◽  
Ghanshyam V. Joshi ◽  
Hasmukh A. Patel ◽  
Pravin G. Ingole ◽  
Haresh M. Mody ◽  
...  


1992 ◽  
Vol 61 (2-3) ◽  
pp. 291-304 ◽  
Author(s):  
N.M. Delzenne ◽  
P.Buc Calderon ◽  
H.S. Taper ◽  
M.B. Roberfroid


2021 ◽  
pp. 247412642110287
Author(s):  
Diana Driscoll ◽  
David Callanan

Purpose: This work reports retinal findings in an adult patient with vitamin B6 deficiency. Methods: A case review of a single patient is presented. Results: A patient with a Roth-type retinal lesion and a history of nonepileptic seizures was found to have lymphocytic colitis. She was treated with pyridoxine, which resolved her seizures and the white-centered hemorrhage. Conclusions: Vitamin B6 deficiency should be considered in the differential diagnosis of patients presenting with white-centered hemorrhages and a history of nonepileptic seizures.



Sign in / Sign up

Export Citation Format

Share Document