scholarly journals Regulation of the activity of ornithine decarboxylase and S-adenosylmethionine decarboxylase in mammary gland and liver of lactating rats. Effects of starvation, prolactin and insulin deficiency

1982 ◽  
Vol 202 (3) ◽  
pp. 693-698 ◽  
Author(s):  
M E Brosnan ◽  
V Ilic ◽  
D H Williamson
Keyword(s):  
Mammary Gland ◽  
Ornithine Decarboxylase ◽  
Milk Production ◽  
Marked Decrease ◽  
Decarboxylase Activity ◽  
Insulin Deficiency ◽  
Fed State ◽  
Simultaneous Injection ◽  
Adenosylmethionine Decarboxylase ◽  
Ornithine Decarboxylase Activity

1. Starvation caused a marked decrease in the activity of ornithine decarboxylase in mammary gland, together with a lesser decrease in the activity of S-adenosylmethionine decarboxylase and a marked fall in milk production. Liver ornithine decarboxylase and S-adenosylmethionine decarboxylase activities were unaffected. 2. Refeeding for 2.5 h was without effect on ornithine decarboxylase in mammary gland, but it returned the S-adenosylmethionine decarboxylase activity in mammary gland to control values and elevated both ornithine decarboxylase and S-adenosylmethionine decarboxylase in liver. 3. Refeeding for 5 h returned the activity of ornithine decarboxylase in mammary gland to fed-state values and resulted in further increases in S-adenosylmethionine decarboxylase in mammary gland and liver and in ornithine decarboxylase in liver. 4. Prolactin deficiency in fed rats resulted in decreased milk production and decreased activity of ornithine decarboxylase in mammary gland. The increase in ornithine decarboxylase activity normally seen after refeeding starved rats for 5 h was completely blocked by prolactin deficiency. 5. In fed rats, injection of streptozotocin 2.5 h before death caused a decrease in the activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase in mammary gland, which could be reversed by simultaneous injection of insulin. Insulin deficiency also prevented the increase in S-adenosylmethionine decarboxylase in liver and mammary gland normally observed after refeeding starved rats for 2.5 h.

scholarly journals Effect of starvation and refeeding on polyamine concentrations and ornithine decarboxylase antizyme in mammary gland of lactating rats

1983 ◽  
Vol 212 (1) ◽  
pp. 149-153 ◽  
Author(s):  
M E Brosnan ◽  
R Farrell ◽  
H Wilansky ◽  
D H Williamson
Keyword(s):  
Mammary Gland ◽  
Nucleic Acid ◽  
Ornithine Decarboxylase ◽  
Acid Content ◽  
Marked Decrease ◽  
Mammary Glands ◽  
Nucleic Acid Content ◽  
Decarboxylase Activity ◽  
Ornithine Decarboxylase Activity ◽  
Polyamine Content

Starvation caused a marked increase in putrescine content in mammary gland of lactating rats, together with a marked decrease in activity of ornithine decarboxylase and appearance of measurable ornithine decarboxylase antizyme. 2. Refeeding for 5 h caused disappearance of free antizyme and ornithine decarboxylase activity returned to the value in fed animals. Putrescine concentration remained elevated. 3. There was no significant change in nucleic acid content of mammary gland from starved rats, but spermidine and spermine contents increased significantly. 4. Refeeding for 5 h returned the spermidine content of mammary glands to ‘fed’ values, and significantly decreased the content of spermine, although it did not reach control values. Thus changes in polyamine content of mammary gland in starved rats are clearly dissociated from changes in either RNA content or activities of polyamine-synthetic decarboxylases. 5. Starvation caused a fall in the content of spermidine in liver, with no change in spermine content. Refeeding for 5 h returned the spermidine content to ‘fed’ values.

scholarly journals Role of pyridoxal phosphate in mammalian polyamine biosynthesis. Lack of requirement for mammalian S-adenosylmethionine decarboxylase activity

1977 ◽  
Vol 166 (1) ◽  
pp. 81-88 ◽  
Author(s):  
A E Pegg
Keyword(s):  
Ornithine Decarboxylase ◽  
Pyridoxal Phosphate ◽  
Vitamin B ◽  
Decarboxylase Activity ◽  
Deficient Diet ◽  
Polyamine Biosynthesis ◽  
Adenosylmethionine Decarboxylase ◽  
Ornithine Decarboxylase Activity

1. Polyamine concentrations were decreased in rats fed on a diet deficient in vitamin B-6. 2. Ornithine decarboxylase activity was decreased by vitamin B-6 deficiency when assayed in tissue extracts without addition of pyridoxal phosphate, but was greater than in control extracts when pyridoxal phosphate was present in saturating amounts. 3. In contrast, the activity of S-adenosylmethionine decarboxylase was not enhanced by pyridoxal phosphate addition even when dialysed extracts were prepared from tissues of young rats suckled by mothers fed on the vitamin B-6-deficient diet. 4. S-Adenosylmethionine decarboxylase activities were increased by administration of methylglyoxal bis(guanylhydrazone) (1,1′-[(methylethanediylidine)dinitrilo]diguanidine) to similar extents in both control and vitamin B-6-deficient animals. 5. The spectrum of highly purified liver S-adenosylmethionine decarboxylase did not indicate the presence of pyridoxal phosphate. After inactivation of the enzyme by reaction with NaB3H4, radioactivity was incorporated into the enzyme, but was not present as a reduced derivative of pyridoxal phosphate. 6. It is concluded that the decreased concentrations of polyamines in rats fed on a diet containing vitamin B-6 may be due to decreased activity or ornithine decarboxylase or may be caused by an unknown mechanism responding to growth retardation produced by the vitamin deficiency. In either case, measurements of S-adenosylmethionine decarboxylase and ornithine decarboxylase activity under optimum conditions in vitro do not correlate with the polyamine concentrations in vivo.

scholarly journals Polyamines and their biosynthetic decarboxylases in various tissues of the young rat during recovery from undernutrition

1977 ◽  
Vol 162 (1) ◽  
pp. 109-121 ◽  
Author(s):  
P A McAnulty ◽  
J P G Williams
Keyword(s):  
Ornithine Decarboxylase ◽  
Liver Weight ◽  
Female Rats ◽  
Male Rats ◽  
Decarboxylase Activity ◽  
Adenosylmethionine Decarboxylase ◽  
Ornithine Decarboxylase Activity ◽  
Male And Female Rats ◽  
Gastrocnemius Muscles ◽  
Ad Libitum Feeding

1. Weanling male and female rats were undernourished for 4 weeks and then rehabilitated by allowing ad libitum feeding. 2. During rehabilitation polyamine-biosynthetic enzymes were examined in the liver, spleen and quadriceps and gastrocnemius muscles. 3. During the first few hours of rehabilitiation there was a marked increase in liver weight, accompanied by a very marked increase in ornithine decarboxylase activity. Increases in the activity of this enzyme in other tissues did not occur until between 2 and 7 days of rehabilitation, at which time there were further increases in enzyme activity in the liver. 4. S-Adenosylmethionine decarboxylase activity also showed marked fluctuations in activity in all the tissues examined. 5. Hepatic putrescine and spermidine concentrations also varied during rehabilitation, but permine concentration remained relatively constant. Both spermine and spermidine were at normal concentrations in the liver from the 10th days of rehabilitation onwards. 6. In all of the tissues examined there were marked sex differences in the parameters studied, particularly in splenic and muscular ornithine decarboxylase activity. 7. In the tissues of the male rats, changes in polyamine synthesis paralled changes in nucleic acid and protein synthesis.

scholarly journals Differential effects of 2-difluoromethylornithine and methylglyoxal bis(guanylhydrazone) on the testosterone-induced growth of ventral prostate and seminal vesicles of castrated rats

1984 ◽  
Vol 219 (3) ◽  
pp. 811-817 ◽  
Author(s):  
K Käpyaho ◽  
A Kallio ◽  
J Jänne
Keyword(s):  
Seminal Vesicle ◽  
Ornithine Decarboxylase ◽  
Seminal Vesicles ◽  
Ventral Prostate ◽  
Decarboxylase Activity ◽  
Adenosylmethionine Decarboxylase ◽  
Ornithine Decarboxylase Activity ◽  
Combined Use ◽  
Sexual Glands ◽  
Stimulation Of

2-Difluoromethylornithine totally prevented any increases in putrescine and spermidine concentrations in the ventral prostate of castrated rats during a 6-day testosterone treatment. Prostatic ornithine decarboxylase activity was inhibited by 80%, whereas S-adenosylmethionine decarboxylase was stimulated by more than 9-fold. In seminal vesicle, the inhibition of putrescine and spermidine accumulation, as well as of ornithine decarboxylase activity, was only minimal, and no stimulation of S-adenosylmethionine decarboxylase was observed. Administration of methylglyoxal bis(guanylhydrazone) to castrated androgen-treated rats resulted in a marked increase in concentrations of all prostatic polyamines. Prostatic ornithine decarboxylase activity was nearly 2 times and adenosylmethionine decarboxylase activity 9 times higher than that of the testosterone-treated animals. In contrast with ventral prostate, methylglyoxal bis(guanylhydrazone) treatment inhibited moderately the accumulation of spermidine and spermine in seminal vesicle, although both ornithine decarboxylase and S-adenosylmethionine decarboxylase activities were stimulated. Difluoromethylornithine inhibited significantly the weight gain of ventral prostate, but methylglyoxal bis(guanylhydrazone) produced a substantial increase in prostatic weight. These changes were largely due to the fact that the volume of prostatic secretion was greatly decreased by difluoromethylornithine, whereas methylglyoxal bis(guanylhydrazone) increased the amount of secretion. Treatment with difluoromethylornithine strikingly increased the methylglyoxal bis(guanylhydrazone) content of both ventral prostate and seminal vesicle, but even under these conditions the drug concentration remained low in comparison with other tissues. The results indicate that a combined use of these two polyamine anti-metabolites does not necessarily result in a synergistic growth inhibition of the androgen-induced growth of male accessory sexual glands.

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