INTERACTIONS OF OESTRONE AND TESTOSTERONE ON MAMMARY GLANDS OF MALE RABBITS

1961 ◽  
Vol 36 (1) ◽  
pp. 141-156 ◽  
Author(s):  
B. Bengtsson ◽  
A. Norgren
Keyword(s):  
Mammary Gland ◽  
Testosterone Propionate ◽  
Mammary Glands ◽  
List Type ◽  
Stunted Growth ◽  
Abnormal Growth ◽  
Growth Reaction ◽  
Extensive Growth ◽  
Higher Doses

ABSTRACT The effect of testosterone and oestrone on the mammary glands of castrated male rabbits was studied. Testosterone propionate was used in daily doses from 0.5 to 80 mg. The doses of oestrone ranged from 0.05 to 25 μg per day. Mammary glands were examined after 14, 28 or 56 days of injections. 1) Testosterone in doses below 20 mg failed to affect the mammary glands. With 40 or 80 mg a distinct, though abnormal growth reaction was consistently obtained. 2) Oestrone in doses lower than 0.5 μg did not stimulate mammary growth. With 0.5 μg and higher doses extensive growth of the mammary glands occurred. Stunted growth and secretion were found in the mammary glands of rabbits injected with 12.5 or 25 μg oestrone. 3) Testosterone in doses of 1 or 5 to 10 mg depressed or abolished the response of the mammary glands to 0.5 μg oestrone. When testosterone, in doses ineffective when given alone, was added to at least 3.125 μg oestrone, the mammary glands developed alveoli. The abnormalities produced by the highest doses of oestrone studied were exaggerated by the addition of testosterone. 4) The observations indicate a complicated interplay between the actions of testosterone and oestrone on the mammary gland of the rabbit. The interactions between testosterone and oestrone are presumably different from those observed between progesterone and oestrone.

EARLY EFFECTS OF TESTOSTERONE PROPIONATE INJECTED INTO 5 DAY OLD RATS

1965 ◽  
Vol 49 (3) ◽  
pp. 453-465 ◽  
Author(s):  
Dora Jacobsohn ◽  
A. Norgren
Keyword(s):  
Testosterone Propionate ◽  
Mammary Glands ◽  
Compensatory Hypertrophy ◽  
List Type ◽  
Vaginal Opening ◽  
Vaginal Smears ◽  
Duration Of Action ◽  
Old Rats ◽  
Early Effects ◽  
Made In

ABSTRACT The present work deals with problems concerning a) factors influencing gonadal growth in rats during the first two weeks of life and b) the duration of action of 1.5 mg testosterone propionate (testosterone) injected subcutaneously into 5 day old rats (androgenized rats). Five groups of experiments were performed. The results were as follows: Injection of testosterone to 5 day old males reduced the growth of testes from 5 days after injection onwards. Semicastration at 1 day after birth was followed within 14 days by a compensatory hypertrophy of the remaining testis. Androgenization did not prevent a compensatory hypertrophy, but the weight of the remaining testis was reduced as compared with uninjected males. Unilateral ovariectomy at 1 day after birth failed to influence the weight of the remaining ovary recorded after 14 days. Observations on the occurrence of first oestrus and the type of vaginal smears were made in spayed rats receiving ovarian transplants in the anterior eye chamber when 15 days old. Either donors or recipients were androgenized. Testosterone had no effect on the ovaries. Intervals between injection of testosterone and vaginal opening decreased with advancing age both in intact and spayed rats. When testosterone was given to 5 or 18 day old rats, vaginal opening occurred after about 19 and 4 days, respectively. The response of mammary glands of spayed rats with or without androgenization indicated that a) testosterone produced an effect when the rats were about 10 days old and b) testosterone was effective for approximately 15 days.

INTERACTIONS OF OESTROGENS AND ANDROGENS ON THE MAMMARY GLAND AND GROWTH OF OTHER TISSUES IN HYPOPHYSECTOMIZED RATS TREATED WITH INSULIN, CORTISONE AND THYROXINE

1962 ◽  
Vol 41 (2) ◽  
pp. 287-300 ◽  
Author(s):  
Dora Jacobsohn
Keyword(s):  
Mammary Gland ◽  
Mammary Glands ◽  
The Body ◽  
List Type ◽  
Simultaneous Treatment ◽  
Abnormal Response ◽  
Hypophysectomized Rats ◽  
Different Doses

ABSTRACT In a previous study it was found that oestrogens are necessary for androgens to elicit a development of alveolar lobules in the mammary glands of rats. Since androgens and oestrogens exert synergistic as well as antagonistic actions on mammary glands of e. g. rabbits, the significance of oestrogens in the response of the mammary gland to androgens was further investigated in the rat. The experiments were designed according to the same principles as previously, that is, the response of the gland itself to oestrogens was modified. This was achieved by treatment of hypophysectomized rats with a) thyroxine (negligible response) and b) thyroxine, cortisone and insulin (marked response). The effect of endogenous androgens was studied in males injected with PMS with or without oestrogens. Gonadectomized rats were injected with testosterone and oestrogens. No oestrogens given: The mammary glands of hypophysectomized males injected with PMS showed an abnormal response, irrespective of simultaneous treatment with thyroxine, cortisone and insulin in various combinations. The result confirms previous work with testosterone. Negligible response of the mammary glands to oestrogens: In hypophysectomized rats treated with thyroxine, oestrogens and PMS or testosterone, the response of the glands was uniform and abnormal. The absence of end buds indicated that the response to oestrogens, if present at all, was suppressed by the androgens. Marked response of the mammary glands to oestrogens: In hypophysectomized rats treated with thyroxine, cortisone and insulin another response of the glands to androgens and oestrogens was found. Besides abnormal structures, alveolar lobules were present. The changes produced with different doses of testosterone and oestrone indicated a complicated interplay of the two hormones. Confirming previous observations, records of the length and weight of the body and of the weight of the liver and heart revealed marked growth in the hypophysectomized rats treated with thyroxine, cortisone and insulin.

THE GROWTH RESPONSES OF MAMMARY GLANDS AND OTHER TISSUES IN HYPOPHYSECTOMIZED FEMALE RATS TREATED WITH THYROXINE, INSULIN, CORTISONE, AND PREGNANT MARE SERUM GONADOTROPHIN

1960 ◽  
Vol XXXIII (II) ◽  
pp. 197-213 ◽  
Author(s):  
B. T. Donovan ◽  
Dora Jacobsohn
Keyword(s):  
Mammary Gland ◽  
Liver Weight ◽  
Mammary Glands ◽  
Female Rats ◽  
List Type ◽  
Growth Responses ◽  
Ovarian Weight ◽  
Heart Ventricles ◽  
Group 3 ◽  
The Individual

ABSTRACT The reaction of the mammary gland of the hypophysectomized rat to endogenous ovarian hormones produced under the influence of serum gonadotrophin (PMS) was studied and the effect of treatment with insulin, thyroxine, and cortisone in various combinations on the reaction examined. Changes in body weight, body length, weight of liver, and weight of heart ventricles were also followed. In hypophysectomized rats treated with PMS alone (group 1) the ovarian weight increased approximately tenfold and the hormones secreted caused vaginal cornification. Mammary growth was absent. With PMS, thyroxine and cortisone (group 2) the ovaries reacted as with PMS alone and vaginal cornification was again observed. Growth of end buds occurred in the mammary glands. The weight of the heart ventricles increased. With PMS, insulin and cortisone (group 3) ovarian weight and function was similar to that in the previous groups but the effect on the mammary gland was greater in that the size was increased, there were numerous side buds and end buds, and a few alveolar lobules. Body and liver weight was also increased. With PMS, thyroxine, insulin and cortisone (group 4) the effect on the ovaries and mammary glands was qualitatively similar to that seen in group 3 but ovarian weight was lower, and mammary growth more extensive. The rats grew in length, increased in weight, and the weight of the liver and heart ventricles was close to that of control animals. The above results support the view that the growth of the mammary gland is dependent upon the metabolic state of the individual.

MODIFICATION BY OESTROGENS OF THE REACTION OF THE RAT'S MAMMARY GLAND TO ANDROGENS

1962 ◽  
Vol 41 (1) ◽  
pp. 88-100 ◽  
Author(s):  
Dora Jacobsohn
Keyword(s):  
Growth Hormone ◽  
Mammary Gland ◽  
Present Finding ◽  
Mammary Glands ◽  
List Type ◽  
Simultaneous Treatment ◽  
Alveolar Development ◽  
Hypophysectomized Rats ◽  
Combined Actions

ABSTRACT The investigation is concerned with the question, whether the mammary gland of the rat reacts with alveolar growth to androgens alone or to the combined actions of androgens and oestrogens. Since it is difficult to deprive a rat of oestrogens, the study was performed under conditions in which the gland itself either does or does not react to oestrogens. The results were as follows: Experiments on hypophysectomized rats treated with insulin and cortisone. – This treatment makes the glands responsive to oestrogens. Administration of oestrogens resulted in alveolar development in response to endogenously produced androgens (males injected with PMS) as well as to testosterone injections (gonadectomized rats). Experiments on hypophysectomized rats. – The glands do not react to oestrogens. – Injections of oestrogens together with PMS or testosterone resulted in the abnormal reaction known to occur in the mammary glands of hypophysectomized rats given androgens alone. Alveoli were absent. Confirming previous results with testosterone, the mammary glands of hypophysectomized males injected with PMS reacted abnormally and the reaction was not normalized by simultaneous treatment of the hypophysectomized rats with insulin and cortisone. The hitherto confusing results obtained by other workers who studied the effects of growth hormone and prolactin on the mammary glands of hypophysectomized rats are discussed, in view of the present finding that a response of the rat's mammary gland to oestrogens is a prerequisite for the production of alveolar lobule development by androgens.

THE SECRETORY CAPACITY OF THE AUTOTRANSPLANTED HYPOPHYSIS AS INDICATED BY THE EFFECTS OF STEROID HORMONES ON THE MAMMARY GLANDS

1962 ◽  
Vol 39 (3) ◽  
pp. 338-354 ◽  
Author(s):  
Kurt Ahrén
Keyword(s):  
Growth Hormone ◽  
Mammary Gland ◽  
Pituitary Gland ◽  
Steroid Hormones ◽  
Testosterone Propionate ◽  
Mammary Glands ◽  
Kidney Capsule ◽  
Alveolar Development ◽  
Rat Mammary Gland ◽  
Secretory Capacity

ABSTRACT The capacity of the rat mammary gland to respond to testosterone stimulation with lobule-alveolar development only when growth hormone is present, has in these experiments been used as a method for studying whether the pituitary gland, autotransplanted into the kidney capsule, can secrete growth hormone. Injections of 0.05 or 0.25 mg of testosterone propionate daily for 14 days did not stimulate any lobule-alveolar development in the mammary glands of castrated rats with autotransplanted hypophysis. When this treatment was given for about 4 weeks, a few alveoli were seen in the mammary glands. In castrated rats with intact pituitary gland the same doses of testosterone propionate stimulated an extense lobule-alveolar development even after only 14 days of treatment. Injections of testosterone propionate together with growth hormone in rats with autotransplanted hypophysis stimulated the same degree of lobule-alveolar development as did injections of testosterone alone in rats with intact pituitary gland. These observations on the mammary glands indicate that there is a considerable deficiency of growth hormone in rats with the pituitary gland autotransplanted into the kidney capsule. These results are discussed, together with the value of the method used for estimating the presence of growth hormone.

The effect of bromocriptine on mammary-gland ultrastructure of hyperprolactinemic rats

1984 ◽  
Vol 42 ◽  
pp. 204-205
Author(s):  
I.C. Murray
Keyword(s):  
Mammary Gland ◽  
Dopamine Agonist ◽  
Alveolar Epithelium ◽  
Mammary Glands ◽  
Female Rats ◽  
Control Group ◽  
Cell Hyperplasia ◽  
Once Daily ◽  
Long Evans

In women, hyperprolactinemia is often due to a prolactin (PRL)-secreting adenoma or PRL cell hyperplasia. RRL excess stimulates the mammary glands and causes proliferation of the alveolar epithelium. Bromocriptine, a dopamine agonist, inhibits PRL secretion and is given to women to treat nonpuerperal galactorrhea. Old female rats have been reported to have PRL cell hyperplasia or adenoma leading to PRL hypersecretion and breast stimulation. Herein, we describe the effect of bromocriptine and consequently the reduction in serum PRL levels on the ultrastructure of rat mammary glands.Female Long-Evans rats, 23 months of age, were divided into control and bromocriptine-treated groups. The control animals were injected subcutaneously once daily with a 10% ethanol vehicle and were later divided into a normoprolactinemic control group with serum PRL levels under 30 ng/ml and a hyperprolactinemic control group with serum PRL levels above 30 ng/ml.

EFFECT OF LOCALLY IMPLANTED OESTROGEN ON THE RESPONSE OF THE RAT'S LACTATING MAMMARY GLAND TO OXYTOCIN

1973 ◽  
Vol 73 (4) ◽  
pp. 700-712 ◽  
Author(s):  
J. D. Bruce ◽  
X. Cofre ◽  
V. D. Ramirez
Keyword(s):  
Mammary Gland ◽  
Mammary Glands ◽  
Myoepithelial Cells ◽  
Recording System ◽  
Saline Infusion ◽  
High Dose ◽  
Low Doses ◽  
Milk Ejection ◽  
Lactating Mammary Gland ◽  
Small Rise

ABSTRACT On the day following delivery (day 1 of lactation) one abdominal mammary gland was implanted with oestrogen and the contralateral gland received an empty needle. At 2, 5 or 10 days of lactation the rats were anaesthetized with pentobarbital and the nipples of both abdominal glands were cannulated and their pressures recorded by means of transducers coupled to an amplifier and recording system. The normal mammary glands of 5-day lactating rats responded to very low doses of oxytocin (Syntocinon®, Sandoz) (5× 10−8 mU) with a rhythmic elevation in pressure. However, saline infusion also evoked a small rise in intra-mammary pressure. Earlier (2 days) and later (10 days) in lactation the responses were smaller. Oestrogen decreases significantly the milk ejection response to oxytocin, and the effect was maximal at day 10 of lactation. Histological observations confirmed the diminished reaction of the gland to oxytocin, since the milk was retained in the alveoli of rats bearing a mammary-oestrogen implant. A paradoxical rise in pressure was detected in normal as well as in oestrogen-implanted glands when the lowest dose of oxytocin was injected in lactating rats which had previously received a high dose of oxytocin (50 mU or 500 mU). These results reinforce the hypothesis that oestrogen alters the milk ejection response to oxytocin and that the mechanism is probably related to changes in the contractility of the myoepithelial cells.

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.

Oxygen concentration in milk of healthy and mastitic cows and implications of low oxygen tension for the killing ofStaphylococcus aureusby bovine neutrophils

1988 ◽  
Vol 55 (4) ◽  
pp. 513-519 ◽  
Author(s):  
Susan J. Mayer ◽  
Avril E. Waterman ◽  
Peter M. Keen ◽  
Neil Craven ◽  
F. John Bourne
Keyword(s):  
Staphylococcus Aureus ◽  
Mammary Gland ◽  
Partial Pressure ◽  
Oxygen Concentration ◽  
Bactericidal Activity ◽  
Mammary Glands ◽  
Low Oxygen ◽  
Low Oxygen Tension ◽  
Bovine Neutrophils ◽  
Venous Plasma

SummaryThe partial pressure of O2in milk from normal cows and from cows with mastitis was measured and the concentrations of O2calculated. Oxygen levels of milk from normal cows were similar to those in venous plasma, but inflammation of the mammary gland led to a dramatic drop in O2concentration to < 10% of control values. Intracellular survival ofStaphylococcus aureusstrain M60 in bovine neutrophils was greater under anaerobic than aerobic conditions. The implications of low O2concentrations in milk from infected mammary glands for the bactericidal activity of bovine neutrophils is discussed.

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.

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