IN VITRO STUDIES ON CARBOHYDRATE METABOLISM IN THE VITAMIN-B6-DEPRIVED RAT

1955 ◽  
Vol 33 (4) ◽  
pp. 562-567
Author(s):  
John R. Beaton
Keyword(s):  
Carbohydrate Metabolism ◽  
Vitamin B6 ◽  
Glucose Utilization ◽  
Female Rats ◽  
Male Rats ◽  
Vitamin B ◽  
Significant Difference ◽  
Aldolase Activity ◽  
Food Consumed

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.

IN VITRO STUDIES ON CARBOHYDRATE METABOLISM IN THE VITAMIN-B6-DEPRIVED RAT

1955 ◽  
Vol 33 (1) ◽  
pp. 562-567
Author(s):  
John R. Beaton
Keyword(s):  
Carbohydrate Metabolism ◽  
Vitamin B6 ◽  
Glucose Utilization ◽  
Female Rats ◽  
Male Rats ◽  
Vitamin B ◽  
Significant Difference ◽  
Aldolase Activity ◽  
Food Consumed

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.

STUDIES ON THE EFFECT OF VITAMIN B6 DEPRIVATION ON CARBOHYDRATE METABOLISM IN THE RAT

1954 ◽  
Vol 32 (6) ◽  
pp. 684-688 ◽  
Author(s):  
J. R. Beaton ◽  
M. E. Goodwin
Keyword(s):  
Lactic Acid ◽  
Carbohydrate Metabolism ◽  
Pyruvic Acid ◽  
Vitamin B6 ◽  
Liver Glycogen ◽  
Blood Levels ◽  
Vitamin B ◽  
Abnormal Metabolism

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.

STUDIES ON THE EFFECT OF VITAMIN B6 DEPRIVATION ON CARBOHYDRATE METABOLISM IN THE RAT

1954 ◽  
Vol 32 (1) ◽  
pp. 684-688
Author(s):  
J. R. Beaton ◽  
M. E. Goodwin
Keyword(s):  
Lactic Acid ◽  
Carbohydrate Metabolism ◽  
Pyruvic Acid ◽  
Vitamin B6 ◽  
Liver Glycogen ◽  
Blood Levels ◽  
Vitamin B ◽  
Abnormal Metabolism

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.

Effect of ornidazole on fertility of male rats: inhibition of a glycolysis-related motility pattern and zona binding required for fertilization in vitro

Reproduction ◽  
2000 ◽  
pp. 127-135 ◽  
Author(s):  
W Bone ◽  
NG Jones ◽  
G Kamp ◽  
CH Yeung ◽  
TG Cooper
Keyword(s):  
Zona Pellucida ◽  
Glucose Utilization ◽  
Cumulus Cells ◽  
Glycolytic Enzyme ◽  
Male Rats ◽  
Fertilization In Vitro ◽  
Swimming Pattern ◽  
Principal Piece ◽  
Free Media

The effects of the male antifertility agent ornidazole on glycolysis as a prerequisite for fertilization were investigated in rats. Antifertility doses of ornidazole inhibited glycolysis within mature spermatozoa as determined from the lack of glucose utilization, reduced acidosis under anaerobic conditions and reduced glycolytic enzyme activity. As a consequence, cauda epididymidal spermatozoa from ornidazole-fed rats were unable to fertilize rat oocytes in vitro, with or without cumulus cells, which was not due to transfer of an inhibitor in epididymal fluid with the spermatozoa. Under IVF conditions, binding to the zona pellucida was reduced in spermatozoa from ornidazole-fed males and the spermatozoa did not undergo a change in swimming pattern, which was observed in controls. The block to fertilization could be explained by the disruption of glycolysis-dependent events, since reduced binding to the zona pellucida and a lack of kinematic changes were demonstrated by control spermatozoa in glucose-free media in the presence of respiratory substrates. The importance of glycolysis for binding to, and penetration of, the zona pellucida, and hyperactivation in rats is discussed in relation to the glycolytic production of ATP in the principal piece in which local deprivation of energy may explain the reduced force of spermatozoa from ornidazole-fed males.

Effects of in vivo gonadal hormone environment on in vitro hGRF-40-stimulated GH release

1985 ◽  
Vol 249 (3) ◽  
pp. E276-E280 ◽  
Author(s):  
W. S. Evans ◽  
R. J. Krieg ◽  
E. R. Limber ◽  
D. L. Kaiser ◽  
M. O. Thorner
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Gonadal Hormone ◽  
Base Line ◽  
Pituitary Cells ◽  
Intact Male ◽  
Castrate Male ◽  
Basal Release

The effects of gender and the gonadal hormone environment on basal and stimulated growth hormone (GH) release by dispersed and continuously perifused rat anterior pituitary cells were examined. Cells from intact male and diestrus day 2 female rats and from castrate male rats either untreated or treated with testosterone (T) or 17 beta-estradiol (E2) were used. Basal GH release (ng/min per 10(7) cells; mean +/- SE) by cells from diestrus day 2 female rats was less than by cells from castrate rats treated with T (4.3 +/- 0.6 vs. 11.4 +/- 2.7, respectively; P less than 0.025). No other differences in basal release were detected. Concentration-response relationships were documented between human GH-releasing factor 40 (hGRF-40; 0.03-100 nM given as 2.5-min pulses every 27.5 min) and GH release. Mean (+/- SE) overall GH release (ng/min per 10(7) cells) above base line was greater by cells from intact male rats (496 +/- 92) than by cells from castrate (203 +/- 37.3; P less than 0.0001), castrate and T-treated (348 +/- 52.8; P = 0.008), or castrate and E2-treated (58.1 +/- 6.8; P less than 0.001) male rats or by diestrus day 2 rats (68.6 +/- 9.5; P = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

STUDIES ON FACTORS INFLUENCING THE ACUTE TOXICITY OF MALATHION AND MALAOXON IN RATS

1967 ◽  
Vol 45 (4) ◽  
pp. 621-631 ◽  
Author(s):  
Jules Brodeur ◽  
K. P. DuBois
Keyword(s):  
Enzymatic Activity ◽  
Young Male ◽  
Female Rats ◽  
Male Rats ◽  
Age Difference ◽  
Adult Males ◽  
Organophosphate Insecticide ◽  
In Vitro Measurements ◽  
Immature Rats

A study was undertaken to investigate the mechanisms responsible for the higher susceptibility of immature rats to the organophosphate insecticide malathion. In vitro measurements of the activity of malathionase in the tissues of rats, at various time intervals after birth, indicated that the livers of immature rats detoxify the insecticide at a much slower rate than do the livers of adult animals. Evidence was obtained which showed that prolonged administration of testosterone causes a significant increase of the enzymatic activity in the livers of castrated young male rats and adult female rats. On the other hand, castration interferes with the maintenance of normal levels of malathionase in adult males and partially prevents the development of the activity in weanlings. Estradiol decreases the enzymatic activity in adult males. It appears, therefore, that the age difference in the susceptibility of rats to malathion might be due, to a large extent, to a slower rate of inactivation of the insecticide by the livers of immature animals. The results obtained also indicate that the sex hormones play an important role in the development and maintenance of normal levels of the enzyme system involved in the degradation of malathion in the livers of rats.

THE ROLE OF THE ADRENAL GLAND IN THE CONTROL OF AMINO ACID INCORPORATION INTO PROTEIN OF ISOLATED RAT LIVER MICROSOMES

1960 ◽  
Vol 21 (2) ◽  
pp. 177-189 ◽  
Author(s):  
A. KORNER
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Female Rats ◽  
Male Rats ◽  
Rat Liver Microsomes ◽  
Hypophysectomized Rats ◽  
Normal Rat ◽  
Secondary Result

SUMMARY 1. Microsomes, isolated from rat liver a day after adrenalectomy, incorporate more radioactive amino acid into their protein in vitro than microsomes from normal rat liver. This enhanced rate of incorporation progressively declines with time after adrenalectomy until it reaches a plateau level which is below the normal rate of incorporation. 2. Following adrenalectomy microsomes isolated from liver of male rats show a greater rise in incorporating ability than those from liver of female rats, and maintain it longer. 3. Most of the increased incorporation observed in the in vitro system soon after adrenalectomy of the rat, and most of the decreased incorporation observed in rats adrenalectomized for some time, results from alterations in the microsomes which change their ability to incorporate activated amino acids into proteins. 4. Treatment of rats with cortisol acetate results in an increase in the ability of liver microsomes to incorporate amino acid into protein. This heightened incorporating ability is probably a secondary result of the breakdown of extrahepatic tissue protein which is stimulated by cortisol. 5. Somewhat similar responses to acute adrenalectomy and to treatment with cortisol were found in hypophysectomized rats. 6. The protein anabolic response of adrenalectomized rats to treatment with insulin, and of adrenalectomized-hypophysectomized rats to treatment with insulin or growth hormone, is greater than that shown by rats which possess adrenal glands.

EFFECT OF LIPOTROPIC AGENTS UPON THE NET SYNTHESIS OF CHOLESTEROL IN THE RAT

1960 ◽  
Vol 38 (1) ◽  
pp. 757-761
Author(s):  
Sailen Mookerjea ◽  
C. C. Lucas
Keyword(s):  
Choline Chloride ◽  
Young Male ◽  
Significant Degree ◽  
Male Rats ◽  
Vitamin B ◽  
Normal Range ◽  
Liver Lipids ◽  
Significant Difference

The content of cholesterol in the bodies of young male rats fed a basal hypolipotropic diet has been compared with that of other rats pair-fed on similar diets supplemented with choline chloride, methionine, or vitamin B12, respectively. Increased efficiency of utilization of the food and variable lipotropic effects were observed, but no significant difference was found in the total amounts of cholesterol at the end of the 3-week test periods. The lipotropic agents do not influence to any significant degree the net biosynthesis of cholesterol in rats fed this type of diet but they do affect the distribution, tending to keep the liver lipids, including cholesterol, in the normal range.

Involvement of cGMP in LHRH-stimulated gonadotropin release.

1978 ◽  
Vol 235 (6) ◽  
pp. E586 ◽  
Author(s):  
Z Naor ◽  
C P Fawcett ◽  
S M McCann
Keyword(s):  
Mechanism Of Action ◽  
Female Rats ◽  
Male Rats ◽  
Camp Content ◽  
Luteinizing Hormone Releasing Hormone ◽  
Gonadotropin Release ◽  
Male And Female Rats ◽  
The Relationship ◽  
Stimulation Of

Anterior pituitary content of cyclic AMP (cAMP) and cyclic GMP (cGMP) has been measured during stimulation of gonadotropin release by luteinizing-hormone-releasing hormone (LHRH) in vitro to gain more information concerning the relationship between the mechanism of action of LHRH and cyclic nucleotides. During the increased gonadotropin release obtained by incubation by hemipituitaries with LHRH (0.25--25 X 10(-9) M) for 180 min, the glands taken from both male and female rats exhibited increased cGMP content, whereas cAMP content rose only in those taken from male rats. The increase in cGMP content was observed after only 2 min in the presence of LHRH (5 X 10(-9) M) and prior to augmented gonadotropin release. The increase in cAMP content in the male glands was detectable only after 60 min of incubation. These results suggest that cGMP might be involved in the mechanism of action of LHRH.

Vasopressin responses and receptors in the mesenteric vasculature of estrogen-treated rats

1986 ◽  
Vol 251 (5) ◽  
pp. H885-H889 ◽  
Author(s):  
J. St-Louis ◽  
A. Parent ◽  
R. Lariviere ◽  
E. L. Schiffrin
Keyword(s):  
Binding Sites ◽  
Pressor Response ◽  
Female Rats ◽  
Maximum Response ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Binding Characteristics ◽  
Vascular Bed ◽  
Mesenteric Vascular Bed

The effect of treatment with estrogens on the biological activity of arginine8 vasopressin (AVP) in the in vitro perfused mesenteric vascular bed and on the binding characteristics of [3H]AVP on membranes prepared from the same vascular bed was studied. Female rats treated with estradiol (400 micrograms/24 h sc), compared with ovariectomized rats, had an increase in the maximum response to AVP (from 128 +/- 3 to 153 +/- 3 mmHg) in the perfused preparation and an increase in the density of AVP binding sites (from 402 to 732 fmol/mg protein) in the membrane preparation. In male rats, the injection of estradiol increased the maximum response to AVP (from 109 +/- 4 to 137 +/- 3 mmHg) and the density of AVP binding sites (from 289 to 519 fmol/mg protein). The effective concentration producing 50% of maximum response of AVP in the perfused preparation was higher in male than in female rats, while the Kd in the binding experiments was similar in the four experimental groups. Our results show that estrogens upregulate the number of AVP binding sites, leading to an increase in the pressor response to AVP in the rat mesenteric vascular bed.

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