IN-VITRO UPTAKE AND METABOLISM OF [3H]CORTICOSTERONE BY MAMMARY GLANDS FROM PREGNANT, LACTATING AND POST-LACTATIONAL RATS AND BY PARAMETRIAL ADIPOSE TISSUE FROM LACTATING RATS

1981 ◽  
Vol 91 (1) ◽  
pp. 81-88 ◽  
Author(s):  
W. H. PEARLMAN ◽  
L.-H. PENG ◽  
M. R. J. PEARLMAN
Keyword(s):  
Adipose Tissue ◽  
Mammary Gland ◽  
Specific Activity ◽  
Physiological State ◽  
Mammary Glands ◽  
Tissue Extracts ◽  
Steroid Substrate ◽  
Corticosteroid Hormone ◽  
Uptake And Metabolism

The study was designed to determine the influence of the physiological state on the invitro uptake and metabolism of glucocorticoid hormone by the mammary gland. [3H]Corticosterone was accordingly incubated with minced mammary glands from pregnant, lactating and post-lactational rats. The total uptake of [3H]corticosteroid was obtained from the concentration of radioactivity by the tissue and the specific activity of the steroid substrate. The extent of 21-acylation was determined as the percentage of the radioactivity in the chromatographed tissue extracts attributable to 21-acyl-[3H]corticosterone. The results indicated that the uptake of [3H]corticosteroid increased with advancing pregnancy, attained a high plateau level during lactation, and steadily declined during the post-lactational period. The extent of 21-acylation of [3H]corticosterone varied from 10 to 40%, fluctuating widely in all physiological states, particularly during the post-lactational period. It was inferred that the stromal elements, presumably the adipocytes, of the mammary gland can also acylate the corticosteroid hormone, a view which gained experimental support from similar studies with minced parametrial adipose tissue from lactating rats.

scholarly journals Regulation of lipogenic capacity in lactating rats

1982 ◽  
Vol 208 (3) ◽  
pp. 611-618 ◽  
Author(s):  
M R Grigor ◽  
A Geursen ◽  
M J Sneyd ◽  
S M Warren
Keyword(s):  
Mammary Gland ◽  
Fatty Acid ◽  
Malic Enzyme ◽  
Fatty Acid Synthase ◽  
Specific Activity ◽  
Mammary Glands ◽  
Lipogenic Enzymes ◽  
Pregnancy And Lactation ◽  
Specific Activities

1. The rate of mammary-gland lipogenesis measured in vivo from 3H2O was suppressed after decreasing the milk demand by decreasing the number of pups from ten to two or three, as well as by giving diets containing lipid [Grigor & Warren (1980) Biochem. J. 188, 61-65]. 2. The specific activities of the lipogenic enzymes fatty acid synthase, glucose 6-phosphate dehydrogenase and ‘malic’ enzyme increased between 6- and 10-fold in the mammary gland and between 2- and 3-fold in the livers during the first 10 days of lactation. The increases in specific activity coupled with the doubling of liver mass which occurred during pregnancy and lactation resulted in considerable differences in total liver activities when compared with virgin animals. 3. Although consumption of a diet containing 20% peanut oil suppressed the activities of the three lipogenic enzymes in the livers, only the ‘malic’ enzyme was affected in the mammary glands. 4. In contrast, decreased milk demand did not affect the specific activities of any of the liver enzymes, whereas it resulted in suppression of all three lipogenic enzymes of the mammary glands. There was no effect on either the cytoplasmic malate dehydrogenase or the lactate dehydrogenase of the mammary gland. 5. In all the experiments performed, the activity of the fatty acid synthase correlated with the amount of material precipitated by the rabbit antibody raised against rat fatty acid synthase.

THE IN VITRO METABOLISM OF MAMMARY GLAND SLICES IN THE PRESENCE OF POSTERIOR PITUITARY LOBE EXTRACTS RICH IN MELANOPHORE-DISPERSING ACTIVITY

1957 ◽  
Vol 15 (4) ◽  
pp. 366-373 ◽  
Author(s):  
T. R. BRADLEY ◽  
G. M. MITCHELL
Keyword(s):  
Mammary Gland ◽  
Guinea Pigs ◽  
Incubation Medium ◽  
Mammary Glands ◽  
Gas Evolution ◽  
Early Lactation ◽  
Posterior Pituitary ◽  
Rats And Mice ◽  
Posterior Pituitary Lobe

SUMMARY Slices cut from mammary glands of rats and mice during gestation and lactation were incubated in vitro in the presence of pig posterior pituitary lobe extracts rich in melanophore-dispersing ('B') activity. Slices taken in early lactation but not during gestation or late lactation showed increased net gas evolution compared with control slices. Similar tissue from rabbits and guinea-pigs did not give rise to this effect, nor did slices of other tissues taken from lactating rats. The increased net gas evolution was not observed in the absence of glucose from the incubation medium. Treatment of the 'B' extract with NaOH or hypophysectomy of the rats prior to use decreased the response.

scholarly journals Lipogranulomas of the mammary glands: diagnosis and treatment

2021 ◽  
Vol 70 (2) ◽  
Author(s):  
Natalia Cara ◽  
◽  
Veronica Svet ◽  
Ion Mereuta ◽  
◽  
...  
Keyword(s):  
Breast Cancer ◽  
Adipose Tissue ◽  
Mammary Gland ◽  
Inflammatory Process ◽  
Pathological Condition ◽  
Scar Tissue ◽  
Mammary Glands ◽  
Diagnosis And Treatment ◽  
Breast Lesions ◽  
Fat Necrosis

Steatonecrosis of the mammary gland is necrosis of its adipose tissue, followed by replacement with scar tissue. Lipogranuloma is known as a benign inflammatory process, necrosis of breast fat occurs due to iatrogenic breast trauma. Most often, fatty necrosis is seen in women with large breasts – in women with small breasts, it develops much less often. It is important to diagnose lipogranulomas because it can often mimic breast cancer. Fat necrosis of the breast is a common pathological condition, with a wide variety of presentations on mammography, ultrasound and MRI. The incidence of fatty necrosis of the breast is estimated at 0.6%, representing 2.75% of all breast lesions.

scholarly journals Evidence that the stimulation of lipogenesis in the mammary glands of starved lactating rats re-fed with a chow diet is dependent on continued hepatic gluconeogenesis during the absorptive period. Effects of a gluconeogenic inhibitory, mercaptopicolinic acid, in vivo

1985 ◽  
Vol 228 (3) ◽  
pp. 727-733 ◽  
Author(s):  
D H Williamson ◽  
V Ilic ◽  
R G Jones
Keyword(s):  
Mammary Gland ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Mammary Glands ◽  
Hepatic Glycogen ◽  
Chow Diet ◽  
Hepatic Gluconeogenesis ◽  
Rapid Stimulation ◽  
Stimulation Of

The rapid stimulation of lipogenesis in mammary gland that occurs on re-feeding starved lactating rats with a chow diet was decreased (60%) by injection of mercaptopicolinic acid, an inhibitor of hepatic gluconeogenesis at the phosphoenolpyruvate carboxykinase step. Mercaptopicolinate had no effect on lipogenesis in mammary glands of fed lactating rats. The inhibition of lipogenesis persisted in vitro when acini from mammary glands of re-fed rats treated with mercaptopicolinate were incubated with [1-14C]glucose. Mercaptopicolinate added in vitro had no significant effect on lipogenesis in acini from starved-re-fed lactating rats. Mercaptopicolinate prevented the deposition of glycogen and increased the rate of lipogenesis in livers of starved-re-fed lactating rats, whereas it had no significant effect on livers of fed lactating rats. Administration of intraperitoneal glucose restored the rate of mammary-gland lipogenesis in re-fed rats treated with mercaptopicolinate to the values for re-fed rats. Hepatic glycogen deposition was also restored, and the rate of hepatic lipogenesis was stimulated 5-fold. It is concluded that stimulation of mammary-gland lipogenesis on re-feeding with a chow diet after a period of starvation is in part dependent on continued hepatic gluconeogenesis during the absorptive period. Possible sources of the glucose precursors are discussed.

scholarly journals The dynamics of morphological changes during in vitro aging of bovine virgin mammary gland neutrophils

2012 ◽  
Vol 47 (No. 12) ◽  
pp. 325-332 ◽  
Author(s):  
Z. Sládek ◽  
D. Vašíčková ◽  
D. Ryšánek
Keyword(s):  
Mammary Gland ◽  
Trypan Blue ◽  
Morphological Changes ◽  
Membrane Integrity ◽  
Mammary Glands ◽  
Progressive Increase ◽  
Apoptotic Bodies ◽  
Bovine Mammary Gland ◽  
Cell Counts

The present study was an in vitro analysis of the dynamics of bovine mammary gland neutrophil apop­tosis based on the detection of morphological changes. The neutrophils were isolated from mammary glands of five virgin heifers. The mammary glands were lavaged, the suspensions were then bacteriologically examined, and total and differential cell counts were made. The cells were cultivated in vitro for 4 hours. After 2, 3 and 4 hours of cultivation, they were panoptically stained, and the proportions of apoptotic neutrophils and trypan blue positive neutrophils were determined. Neutrophil apoptosis and impaired cytoplasmic membrane integrity of neutrophils were already observed in the mammary gland lavages (11.9% and 0.8%, respectively). During the cultivation, a progressive increase in the number of apoptotic neutrophils in various stages of apoptosis – karyopyknosis, zeiosis and apoptotic bodies – was observed. Karyopyknotic neutrophils represented a dominant part of the apoptotic neutrophil population in the course of the whole cultivation. The most intensive increase was observed in zeiosis, whereas the levels of apoptotic bodies remained the same. After 4 hours of cultivation, 31.7% apoptotic neutrophils and 9.8% trypan blue positive neutrophils (i.e. Secondary necrotic cells) were found. The results of this work show that spontaneous apoptosis and secondary neutrophil necrosis must be taken into account during in vitro cultivations of bovine mammary gland neutrophils.

scholarly journals Forms of lipoprotein lipase in rat tissues: in adipose tissue the proportion of inactive lipase increases on fasting

1996 ◽  
Vol 313 (3) ◽  
pp. 893-898 ◽  
Author(s):  
Martin BERGÖ ◽  
Gunilla OLIVECRONA ◽  
Thomas OLIVECRONA
Keyword(s):  
Adipose Tissue ◽  
Lipoprotein Lipase ◽  
Translational Regulation ◽  
Specific Activity ◽  
Catalytic Efficiency ◽  
Rat Tissues ◽  
Tissue Extracts ◽  
Significant Difference ◽  
Lpl Mass ◽  
Fasted Rats

Previous studies have shown that the ratio of lipoprotein lipase (LPL) catalytic activity to LPL mass in tissues differs in different conditions, but it is not clear whether this occurs by a change in the catalytic efficiency of the LPL molecules, or because of a shift in the relation between active and inactive forms of the enzyme. To explore this, we have measured LPL activity and mass in detergent extracts of rat tissues. LPL specific activity was high and similar in heart, skeletal muscle, lung and brain. The liver had significantly lower specific activity, which is in accord with previous findings that the liver takes up and catabolizes LPL. The specific activity was also low in adipose tissue from fasted rats. When tissue extracts were applied to columns of heparin–agarose and eluted by a gradient of NaCl, a peak of active LPL was eluted at 1.0 M NaCl, but there was also a peak of inactive LPL protein, which was eluted at 0.6 M NaCl. In adipose tissue, LPL activity decreased by 70–80% during an overnight fast, whereas LPL mass decreased by only 20–40%. The mass ratio between inactive and active LPL, as separated by heparin–agarose chromatography, increased from 0.5 to over 2 during the fast. In hearts there was no significant difference between fed and fasted rats in total LPL activity, LPL mass or in the distribution between inactive and active forms. The results indicate that the relation between inactive (probably monomeric) and active (dimeric) forms of LPL is a target for post-translational regulation in adipose tissue.

scholarly journals Immunochemical studies with soluble and mitochondrial pyruvate carboxylase activities from rat tissues

1970 ◽  
Vol 119 (4) ◽  
pp. 735-742 ◽  
Author(s):  
F. J. Ballard ◽  
R. W. Hanson ◽  
Lea Reshef
Keyword(s):  
Adipose Tissue ◽  
Mammary Gland ◽  
Brown Adipose Tissue ◽  
Rat Liver ◽  
White Adipose Tissue ◽  
Pyruvate Carboxylase ◽  
Specific Activity ◽  
Rat Liver Mitochondria ◽  
Rat Tissues ◽  
Brown Adipose

1. Pyruvate carboxylase (EC 6.4.1.1), purified from rat liver mitochondria to a specific activity of 14 units/mg, was used for the preparation of antibodies in rabbits. 2. Tissue distribution studies showed that pyruvate carboxylase was present in all rat tissues that were tested, with considerable activities both in gluconeogenic tissues such as liver and kidney and in tissues with high rates of lipogenesis such as white adipose tissue, brown adipose tissue, adrenal gland and lactating mammary gland. 3. Immunochemical titration experiments with the specific antibodies showed no differences between the inactivation of pyruvate carboxylase from mitochondrial or soluble fractions of liver, kidney, mammary gland, brown adipose tissue or white adipose tissue. 4. The antibodies were relatively less effective in reactions against pyruvate carboxylase from sheep liver than against the enzyme from rat tissues. 5. Pyruvate carboxylase antibodies did not inactivate either propionyl-CoA carboxylase or acetyl-CoA carboxylase from rat liver. 6. It is concluded that pyruvate carboxylase in lipogenic tissues is similar antigenically to the enzyme in gluconeogenic tissues and that the soluble activities of pyruvate carboxylase detected in many rat tissues do not represent discrete enzymes but are the result of mitochondrial damage during tissue homogenization.

scholarly journals Pyruvate carboxylase in lactating rat and rabbit mammary gland

1969 ◽  
Vol 111 (3) ◽  
pp. 263-271 ◽  
Author(s):  
Bilquis Gul ◽  
R. Dils
Keyword(s):  
Mammary Gland ◽  
Pyruvate Carboxylase ◽  
Freeze Drying ◽  
Specific Activity ◽  
Subcellular Fractionation ◽  
Mammary Glands ◽  
Mitochondrial Fraction ◽  
Freezing And Thawing ◽  
Rat Mammary Gland ◽  
Assay Conditions

1. Pyruvate carboxylase [pyruvate–carbon dioxide ligase (ADP), EC 6.4.1.1] was found in cell-free preparations of lactating rat and rabbit mammary glands, and optimum assay conditions for this enzyme were determined. 2. Subcellular-fractionation studies with marker enzymes showed pyruvate carboxylase to be distributed between the mitochondrial and soluble fractions of lactating rat mammary gland. Evidence is presented that the soluble enzyme is not an artifact due to mitochondrial damage. 3. In contrast, pyruvate carboxylase in lactating rabbit mammary gland is confined to the mitochondrial fraction. 4. The final product of pyruvate carboxylase action in the mitochondrial and particle-free supernatant fractions of lactating rat mammary gland was shown to be citrate. 5. The effects of freeze-drying, ultrasonic treatment and freezing-and-thawing on the specific activity of mitochondrial pyruvate carboxylase were investigated.

BREAKDOWN OF [3H]OXYTOCIN BY RAT TISSUES IN VITRO

1973 ◽  
Vol 59 (2) ◽  
pp. 305-312
Author(s):  
SANDRA M. EGAN ◽  
A. LIVINGSTON
Keyword(s):  
Skeletal Muscle ◽  
Mammary Gland ◽  
Incubation Medium ◽  
Rat Tissues ◽  
Tissue Uptake ◽  
Tissue Extracts ◽  
Rat Mammary Gland

SUMMARY Tissue uptake of oxytocin by rat mammary gland, uterus, heart and skeletal muscle was demonstrated by incubation of these tissues with 3H-labelled oxytocin. Chromatography of tissue extracts showed that some breakdown of oxytocin had occurred after only 30 s. However, in all cases there was no breakdown of oxytocin in the corresponding incubation medium. This indicated that the breakdown of oxytocin occurred within the tissues.

INTERACTION BETWEEN PROLACTIN AND THYROXINE IN MOUSE MAMMARY GLAND LOBULO-ALVEOLAR DEVELOPMENT IN VITRO

1969 ◽  
Vol 45 (4) ◽  
pp. 579-583 ◽  
Author(s):  
D. V. SINGH ◽  
H. A. BERN
Keyword(s):  
Mammary Gland ◽  
Synergistic Effects ◽  
Synthetic Medium ◽  
Mammary Glands ◽  
Mouse Mammary Gland ◽  
Intact Female ◽  
Antagonistic Effects ◽  
Alveolar Development ◽  
Development In Vitro

SUMMARY Intact female BALB/cCrgl mice, 3–4 weeks old, were pretreated with oestrogen and progesterone for 9 days. Whole mammary glands from these mice were cultivated for 5 days in a synthetic medium supplemented with aldosterone (A), prolactin (MH) and insulin (I), with and without thyroxine (T4) at concentrations ranging from 0·01 to 5 μg./ml. A medium containing 1 μg. A +5 μg.MH +5 μg.I/ml. was generally optimal for lobulo-alveolar development. Addition of thyroxine to this combination resulted in a decrease in development which was highly significant at higher concentrations. However, when cultures were maintained in media containing suboptimal or low amounts of prolactin (1 μg. A + 3 μg. MH +5 μg. I/ml. and 1 μg. A + 1 μg. MH +5 μg. I/ml., respectively), the results indicate two possible effects of thyroxine: lower amounts of thyroxine had synergistic effects, whereas greater amounts had antagonistic effects on lobulo-alveolar development.

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