Morphometric and hormonal study of the effect of utrica diocia extract on mammary glands in rats / Estudio morfométrico y hormonal del efecto de extracto de utrica diocia en glándulas mamarias en ratas

Urtica diocia is a multipurpose herb in traditional medicine. Its hydroalcoholic extract (20, 50 and 100 mg/kg) administered interaperitoneally to Wistar female rats for 21 consequent days resulted in significant increase in the number of alveoli of mammary glands in doses of 20 and 50 mg/kg. Changes in serum prolactin and alveolar diameter were not significant in comparison with control group. Also, there was an increase in serum prolactin and alveolar diameter in doses of 20 and 50 mg/kg. Utrica diocia extract has positive effects on mammary glands.

Urtica diocia es una hierba de usos múltiples en la medicina tradicional. Su extracto hidroalcohólico (20, 50 y 100 mg/kg) administrado por vía intraperitoneal en ratas hembras Wistar de 21 días resultaron en un aumento significativo en el número de alvéolos de las glándulas mamarias en dosis de 20 y 50 mg/kg. Los cambios en la prolactina sérica y el diámetro alveolar no fueron significativos en comparación con el grupo control. Además, hubo un aumento en la prolactina sérica y en el diámetro alveolar en dosis de 20 y 50 mg/kg. El extracto de Urtica diocia tiene efectos positivos sobre las glándulas mamarias.

Efeitos da tibolona sobre o parênquima mamário: estudo experimental / Effects of tibolone on the breast parenchyma: experimental study

OBJETIVO: Avaliar o efeito da terapia hormonal com tibolona, em três períodos de tempo diferentes, sobre o tecido mamário de ratas castradas. MÉTODO: Foram utilizadas 60 ratas Wistar adultas e virgens, submetidas à ooforectomia. Após 21 dias de pós-operatório (PO), confirmado o hipoestrogenismo, os animais foram divididos aleatoriamente em 6 grupos: tibolona 1 (n=10) recebeu tibolona 1 mg/dia por 23 dias, tibolona 2 (n=10), por 59 dias, tibolona 3 (n=10), por 118 dias; os subgrupos controle 1 (n=8), controle 2 (n=7) e controle 3 (n=10) receberam a água destilada por 23, 59 e 118 dias, respectivamente. Após o tratamento, foram ressecados seis pares de mamas, destinados à análise histológica pela coloração de hematoxilina e eosina (HE); o procedimento seguiu de eutanásia. Os parâmetros histológicos avaliados foram: hiperplasia epitelial e atividade secretora (AS). As variáveis foram submetidas à análise estatística, adotando-se como significante p<0,05. RESULTADOS: Foram observadas alterações histológicas em 20/55 ratas, sendo: hiperplasia epitelial leve (HEB1) em 7/55, hiperplasia epitelial moderada (HEB2) em 5/55, hiperplasia alvéolo-nodular (HAN) em 7/55, atipia sem proliferação epitelial em 1/55, não sendo encontrada hiperplasia severa (HEB3). Encontrou-se AS em 31/55 das ratas. A AS foi significativamente maior no grupo tibolona (T), em todos os tempos avaliados (p=0,001). As alterações histológicas analisadas não foram significantes comparando (p>0,05) os grupos controle (C) e T. A variável tempo de exposição à droga não apresentou significância, quando comparados os três períodos avaliados. CONCLUSÃO: Não foi verificada relação entre as alterações histológicas e a terapêutica com tibolona em curto, médio e longo prazo. .

OBJECTIVE: To assess the effect of tibolone on mammary tissue of castrated rats over 3 different periods of time. METHODS: Sixty virgin female Wistar rats were submitted to oophorectomy. Twenty-one days after surgery, with hypoestrogenism confirmed, the experimental rats were randomly assigned to six groups: Tibolone 1 (n=10) received tibolone 1 mg/day for 23 days, tibolone 2 (n=10) for 59 days and tibolone 3 (n=10) for 118 days. The groups control 1 (n=8), control 2 (n=7) and control 2 (n=10) received distilled water for 23, 59 and 118 days, respectively. After treatment, all six pairs of mammary glands were removed and stained with hematoxylin and eosin (HE) for histological analysis after euthanasia. The histological parameters evaluated were: epithelial cell proliferation and secretory activity. The variables were analyzed statistically, with the level of significance set at 0.05. RESULTS: Histological changes were observed in 20/55 rats, mild epithelial hyperplasia in 7/55, moderate epithelial hyperplasia in 5/55, alveolar-nodular hyperplasia in 7/55, atypia without epithelial proliferation in 1/55, and no cases of severe epithelial hyperplasia were found. Secretory activity was observed in 31/55 rats. The secretory activity was significantly higher in the tibolone groups compared to control at all the time points assessed (p=0,001). The histological changes were did not show significance when the control and tibolone groups were compared. The time of exposure to tibolone did not show significance when the three different periods of evaluation were compared. CONCLUSION: No relation between histological modification and tibolone treatment was verified after short-, medium- and long-term treatment. .

Efeitos de altas doses de genisteína sobre o epitélio mamário de ratas / Effects of high doses of genistein on mammary gland of female rat

OBJETIVO: avaliar os efeitos de altas doses de genisteína sobre o epitélio mamário de ratas adultas. MÉTODOS: após 28 dias da ooforectomia, cinquenta ratas adultas foram divididas em cinco grupos, a saber: um controle (Ctrl), três que receberam genisteína (GEN) nas doses de 46 mg/kg (GEN46), 125 mg/kg (GEN125) e 250 mg/kg (GEN250), e um que recebeu estrogênios conjugados equinos na dose de 50 µg/kg (ECE). As substâncias foram administradas diariamente durante 30 dias consecutivos por gavagem e na última semana de tratamento foi efetuado exame colpocitológico durante sete dias consecutivos. Após o tratamento, os animais foram anestesiados, amostras de sangue foram retiradas para determinação do estradiol e da progesterona, e o primeiro par de mamas inguinais retirado e processado para análise histomorfométrica. Os dados obtidos foram submetidos à análise de variância complementada pelo teste de Tukey-Kramer (p<0,05). RESULTADOS: nos grupos Ctrl e tratados com as diferentes doses de GEN as mamas apresentaram-se atróficas, no entanto mostraram-se desenvolvidas no grupo ECE, onde se notou a presença de inúmeros ductos e alvéolos mamários contendo material eosinófilo em seu interior. A morfometria mostrou maior área de parênquima mamário no grupo ECE (98.870,1±550,4 µm²* por mm²; p<0,05) comparado aos outros grupos (Ctrl=36.875,6±443,4; GEN46=37.001,7±557,4; GEN125=36.480,8±658,3 e GEN250=37.502,8±669,3). O mesmo ocorreu em relação ao número de alvéolos e ductos mamários no grupo ECE (33,2±6,9* por mm²; p<0,05) em relação aos outros grupos (Ctrl=10,4±2,1, GEN 46=11,2±3,1; GEN 125=11,6±2,1 e GEN 250=12,3±2,3). Os níveis de estradiol mostraram-se aumentados no grupo ECE em relação aos outros grupos (9,4±1,7 pg/mL; p<0,05), sendo que os níveis séricos de progesterona mostraram-se semelhantes em todos os grupos de estudo. CONCLUSÃO: a administração de genisteína em altas doses não apresentou efeito proliferativo no tecido mamário de ratas.

PURPOSE: to evaluate the effects of high doses of genistein on the mammary glands of adult female rats. METHODS: Twenty-eight days after oophorectomy, 50 adult female rats were divided into five groups, as follows: a control group (Ctrl), three rats that received genistein (GEN) at the doses of 46 mg/kg (GEN46;), 125 mg/kg (GEN125) and 250 mg/kg (GEN250); one group received conjugated equine estrogen at the dose of 50 µg/g (ECE50). The substances were administered daily for 30 consecutive days by gavage and in the last week of the period of treatment, colpocytological exams were carried out for seven consecutive days. After treatment, the animals were anesthetized, blood samples were collected for estradiol and progesterone determination and the first pair of inguinal mammary glands was removed and processed for histomorphometric analysis. Collected data were subjected to analysis of variance supplemented by the Tukey-Kramer test (p<0.05). RESULTS: the ctrl group and the ones treated with different doses of GEN showed atrophic mammary glands, whereas the glands were more developed in the ECE group, where numerous mammary ducts and alveoli were observed. Morphometry showed a larger area of mammary parenchyma in the ECE group (98.870.1±550.4 µm²* per mm²; p<0.05) compared with other groups (Ctrl=36.875.6±443.4; GEN46=37.001.7±557.4; GEN125=36.480.8±658.3 and GEN250=37.502.8±669.3). The same occurred in the number of alveoli in the ECE group (33.2±6.9* per mm²; p<0.05) compared to the other groups (Ctrl=10.4±2.1, GEN46=11.2±3.1; GEN125=11.6±2.1 and GEN250=12.3±2.3). The estradiol level was higher in the ECE group compared to the other groups (9.4±1.7 pg/mL; p<0.05), whereas serum levels of progesterone were similar in all groups. CONCLUSION: the administration of genistein at high doses had no trophic effect on the mammary glands of rats.

Efeito da trimegestona sobre o tecido mamário de ratas castradas / Effect of trimegestone on mammary gland of castrated rats

OBJETIVO: Avaliar o efeito da trimegestona sobre a proliferação celular do tecido mamário de ratas castradas. MÉTODOS: Foram utilizadas 45 ratas adultas e virgens, da linhagem Wistar, submetidas à castração. Após o 60º dia da castração, confirmado o hipoestrogenismo, os animais foram divididos aleatoriamente em três grupos, conforme o tratamento proposto: controle (n=15) recebeu soro fisiológico 0,9 por cento; estrogênio (n=15) recebeu 17 beta-estradiol; e combinado (n=15) recebeu 17 beta-estradiol associado à trimegestona, todos por 60 dias consecutivos. Após o término do tratamento, procedeu-se a exérese das mamas inguinais, destinadas a análise morfométrica pela coloração de hematoxilina e eosina (HE) e imuno-histoquímica pela quantificação do anticorpo anti-PCNA no tecido mamário, seguido de eutanásia. Os parâmetros morfométricos avaliados foram: proliferação celular epitelial, atividade secretora e alteração do estroma mamário. Ocorreram nove óbitos durante o experimento. As variáveis foram submetidas à análise estatística adotando-se como significante p<0,05. RESULTADOS: Foram observadas alterações histológicas em 16/36 ratas, hiperplasia epitelial leve em 13/36, hiperplasia epitelial moderada em 3/36, não sendo encontrada hiperplasia epitelial severa. Encontrou-se fibrose no estroma em 10/36 e atividade secretora em 5/36 das ratas. Todas as variáveis do estudo morfométrico foram significantes comparando-se os grupos controle e estrogênio (p=0,03), e nenhuma foi significante na comparação dos grupos controle e combinado (p=0,4). A análise imuno-histoquímica não mostrou diferença entre os grupos. CONCLUSÃO: Os hormônios usados em ratas castradas aumentaram a proliferação de células mamárias, tanto o 17 beta-estradiol isolado quanto associado à trimegestona, porém este efeito parece ser menor quando se emprega a associação, o mesmo ocorrendo em relação à fibrose do estroma mamário.

PURPOSE: To evaluate the efect of trimegestone on the histological changes of the mammary tissue of castrated rats. METHODS: Forty-five virgin female Wistar rats were used after oophorectomy. Sixty days after surgery, with hypoestrogenisms confirmed, the experimental rats were randomly assigned to three groups of 15 animals each, when then the specific treatment for each group was started. The control group (C) and experimental groups 1 and 2 respectively received 0.9 percent saline solution, 17-beta-estradiol and 17-beta-estradiol in combination with trimegestone for 60 consecutive days. After the end of treatment , the inguinal mammary glands were removed, stained with hematoxylin and eosin (HE) for morphometry and examined by immunohistochemistry for the quantification of anti-PCNA antibody in the mammary tissue, followed by euthanasia. The morphometric parameters evaluated were: epithelium cell-proliferation, secretor activity and mammary stroma changes. There were nine deaths during the experiment. The variables were submitted to statistical analysis adopting the 0.05 level of significance. RESULTS:Histological changes were observed in 16/36 rats, mild epithelial hyperplasia in 13/36, moderate epithelial hyperplasia in 3/36, with no cases of severe epithelial hyperplasia. Stromal fibrosis was found in 10/36 and secretory activity in 5/36 rats. All morphometric variables were significant in the estrogen group compared to control (p=0.0361), although there were no difference between the group receiving combined treatment and the controls (p=0.405). The immunohistochemical analysis showed no difference between groups. CONCLUSIONS:The hormones administered to castrated rats, i.e., 17 beta-estradiol alone or in combination with trimegestone, increased the proliferation of breast cells, but this effect appeared to be lower in the combined treatment, the same occurring regarding fibrosis of the mammary stroma.

Histomorfometria da mama de ratas tratadas com estrogênio e/ou progestagênio / Breast histomorphometry of rats treated with estrogen and/or progestogen

OBJETIVO: Avaliar as alterações histomorfométricas nas mamas de ratas tratadas com estrogênio e/ou progestagênio por curto período de tempo. MÉTODOS: Foram divididas em quatro grupos 40 ratas ooforectomizadas: GC-recebeu veículo; GE-recebeu benzoato de estradiol (37,6 µg/animal); GP-recebeu acetato de medroxiprogesterona (11,28 mg/animal) e, GEP-recebeu benzoato de estradiol (37,6 µg/animal) e acetato de medroxiprogesterona (11,28 mg/animal). No grupo GE, o estradiol foi administrado durante sete dias, por via subcutânea. Já no grupo EP o estradiol foi administrado nos primeiros sete dias e o progestagênio por mais 23 dias, por via subcutânea. Vinte e quatro horas após a última administração dos hormônios, os animais foram anestesiados e o primeiro par de mamas inguinais removido, imerso em formaldeído a 10 por cento e processado para inclusão em parafina, sendo os cortes corados pela Hematoxilina-Eosina. Foram avaliadas a morfologia e a área ocupada pelo parênquima mamário, sendo os dados submetidos à análise de variância complementado pelo teste de Kruskal-Wallis (p < 0,05). RESULTADOS: As mamas no grupo-controle apresentaram-se atrofiadas, sendo que, nos animais dos grupos GE e GEP, nota-se a presença de alvéolos típicos contendo secreção no seu interior, já nos animais tratados somente com progestagênio (GP) notam-se alvéolos formados por células volumosas que ocupam praticamente todo o lúmen alveolar. A morfometria mostrou haver maior área de parênquima mamário nos animais tratados com hormônios (GE = GP > GEP > GC; p < 0,05) CONCLUSÃO: O estradiol e o progestagênio apresentaram efeito proliferativo no parênquima mamário. No entanto, a administração prévia de estradiol modifica a ação do progestagênio no tecido mamário da rata.

OBJECTIVE: To evaluate the breast histomorphometric changes in rats treated with estrogen and/or progestogen for a short period of time. METHODS: Forty oophorectomized rats were divided into four groups: GC, vehicle; GE, treated with estradiol benzoate (37.6 mg/animal); GP, treated with medroxyprogesterone acetate (11.2 mg/animal) and GEP, treated with estradiol benzoate (37.6 mg/animal) plus medroxyprogesterone acetate (11.28 mg/animal). In GE group, estradiol was administered subcutaneously for seven days; in GEP group, estradiol was administered once in a day for the first seven days and the progestogen over the next 23 days both subcutaneously. Twenty-four hours after the last hormone administration, the animals were killed upon deep anesthesia and the first inguinal breasts were removed, fixed in 10 percent formaldehyde and processed to be included in paraffin, with the sections being stained by hematoxylin-eosin. Morphology and the area occupied by mammary parenchyma were assessed, with the data undergoing analysis of variance followed by the Kruskal-Wallis test (p < 0.05). RESULTS: The control group breasts were found atrophic and, in GE and GEP group animals, typical alveoli with secretion inside are present; in progestogen-treated animals (GP), alveoli formed by large cells occupying almost the entire alveolar lumen are noted. Morphometric analysis showed a larger mammary parenchyma area in hormone-treated animals (GE = GP > GEP > GC; p < 0.05). CONCLUSION: Estradiol and progestogen had a proliferative effect on mammary parenchyma. However, prior estradiol administration changes the progestogen action on rat mammary tissue.

Proliferação, apoptose e histomorfometria da glândula mamária de ratas tratadas com tiroxina na lactação e ao desmame e desenvolvimento dos filhotes / Proliferation, apoptosis and mammary gland histomorphometry of thyroxine-treated rats on lactation and after weaning and development of offspring

O objetivo deste estudo foi avaliar a histomorfometria e a taxa de proliferação e apoptose da glândula mamária de ratas tratadas com tiroxina pela imuno-expressão de CDC-47 e caspase-3, respectivamente. Também foi avaliado o desenvolvimento dos filhotes de ratas tratadas com tiroxina. Foram utilizadas 36 ratas distribuídas em dois grupos, tratado com tiroxina e controle. Após 60 dias de tratamento com tiroxina, as ratas foram acasaladas. Seis animais/grupo foram sacrificados no 2° e 21° dias de lactação e no 5° dia após o desmame. Houve diferença significativa entre grupos apenas no quinto dia após o desmame. O tratamento com tiroxina aumentou a taxa de apoptose caracterizada pela maior expressão de caspase-3 nas células do epitélio mamário. As mães tratadas com tiroxina apresentaram comportamento alterado, mas não houve diferença significativa no que se refere aos cuidados com o filhote quanto a higienização e aquecimento. Levando-se em consideração o sexo e o tamanho da ninhada, os filhotes das ratas tratadas com tiroxina e controle não apresentaram diferença significativa de peso ao desmame. Conclui-se que a administração de baixas doses de tiroxina aumenta a taxa de apoptose, caracterizada pelo aumento da expressão de caspase-3 no epitélio mamário cinco dias após o desmame, mas não altera a taxa de proliferação celular e o comportamento materno.

The purpose of this study was to evaluate mammary gland histomorphometry and proliferation rate and apoptosis of thyroxine-treated rats by CDC-47 and caspase-3 immunoexpression. The development of thyroxine-treated rats offspring was also evaluated. Thirty-six female rats were used, distributed in two groups, treated and non-treated with thyroxine. After 60 days of treatment, with thyroxine, rats were mated. Six animals/group were sacrificed on the 2nd and 21st days of lactation and on the 5th day after weaning. A significant difference was observed between groups only on the 5th day after weaning. Thyroxine treatment increased apoptosis rate, which was characterized by a higher caspase-3 expression in mammary epithelial cells. Thyroxine-treated mothers presented changed behavior, but there was no significant difference regarding taking care of offspring, as for cleaning offspring and keeping them warm. Taking into account sex and size of offspring, those from control and thyroxine-treated mothers presented no significant difference of weight and weaning. In conclusion, administering low doses of thyroxine increases apoptosis rate, which is characterized by the increased caspase-3 immunoexpression in mammary epithelial cells 5 days after weaning. But does not affect proliferation rate and development of thyroxine-treated rats offspring.

A comparative study on the protective effects of 17beta-estradiol, biochanin A and bisphenol A on mammary gland differentiation and tumorigenesis in rats.

Mammary tissue differentiation and tumorigenesis were studied in female rats following subcutaneous injection at 2, 4 and 6 days after birth with low or high doses of 17beta-estradiol (0.1 or 10 microg; E2), biochanin A (0.1 or 10 mg; BCA) or bisphenol A (0.1 or 10.0 mg; BPA). Half of the rats were killed on day 35 to analyze the terminal end bud (TEB), terminal duct (TD) and alveolar bud (AB) of the mammary tissue. The remaining rats were injected, ip, with a dose of 50 mg/kg of N-nitroso-N-methylurea (MNU) at 7 weeks of age and sacrificed 26 weeks later. The incidence and multiplicity of mammary tumors (MT) decreased among all three different treated groups, dose-dependently. However, the pattern of mammary gland differentiation varied. No significant difference was observed after E2 administration. TEB decreased dose-dependently in BCA treated groups and the number of TD and AB were suppressed significantly in BPA high dose group.

Morphological changes induced by testosterone in the mammary glands of female Wistar rats

Increased levels of androgens in postmenopausal women are considered to be a risk factor for breast cancer. Testosterone, alone or in combination with estrogen, induces epithelial dysplasia and mammary tumors in Noble rats. Since this model of hormone-induced neoplasia has not been reported in other rat strains, we studied the effect of testosterone on the mammary gland morphology of female Wistar rats. Sixty adult, non-castrated, female Wistar rats were implanted in the dorsum midline with a silicone tube containing 50 mg testosterone (testosterone propionate in 30 animals and non-esterified testosterone in the remaining 30 animals) and 20 additional animals were implanted with empty tubes and used as control. Five animals per group were killed 30, 60, 90, 120, 150, and 180 days after implantation, and the mammary glands were dissected, fixed and embedded in paraffin. Histological sections were then stained with hematoxylin and eosin and picrosyrius red for collagen visualization. Morphological and morphometric analysis demonstrated ductal proliferation and acinotubular differentiation with secretory activity in all treated animals, peaking at 90 days of androgen exposure. After 90 days the proliferation of acinar epithelial cells was evident, but there was a progressive reduction of secretory differentiation and an increase in intralobular collagen fibers. There was no morphological evidence of dysplastic changes or other pre-neoplastic lesions. Testosterone treatment applied to adult, non-castrated female Wistar rats induced a mammary gland hyperplasia resembling the lactating differentiation, with progressive reduction in secretory differentiation.

Heterogeneity of transport systems for L-glutamine in mouse mammary gland.

The characteristics of the transport systems of L-glutamine in lactating mouse mammary gland have been studied. L-glutamine uptake was mediated by three Na+-dependent and one Na+-independent systems. The 2-(methylamino)isobutyric acid-sensitive component of Na+-dependent uptake exhibited the usual characteristics of system A. The other two Na+-dependent systems, which we have named BCI(-)-dependent and BCl(-)-independent, are the new systems identified. These are broad specificity systems and were discriminated on the basis of inhibition analysis, Cl- dependency and the effect of preloading mammary tissue with amino acids. While L-aspargine inhibited the uptake of L-glutamine via both these broad specificity systems, L-homoserine inhibited the uptake of L-glutamine via only BCl(-)-dependent system. The uptake of L-glutamine via the BCl(-)-independent system was upregulated by preloading mammary tissue with L-serine, while BCl(-)-dependent system was unaffected. The Na+-independent uptake of L-glutamine was inhibited by 2-aminobicyclo-(2,2,1)heptane carboxylic acid and other neutral amino acids, and identified as the system L.

Characterization of anionic amino acid transport systems in mouse mammary gland.

L-glutamate was transported into mammary tissue via Na(+)-dependent system XAG- that strongly interacted with both D- and L-isomers of aspartate but only with L-isomer of glutamate. Replacement of Cl- by gluconate from the extracellular medium did not affect the uptake of L-glutamate. Although neutral amino acids weakly inhibited the uptake of L-glutamate, there was no evidence for the heterogeneity of anionic amino acid transport system. The XAG- system was inhibited by sulfhydryl group blocking reagent N-ethylmalemide. Low pH (6) partially inhibited the uptake by L-glutamate by mammary tissue. Prior loading of mammary tissue with L-glutamate slightly down regulated its uptake. Culturing pregnant mouse mammary tissue explants in vitro in the presence of lactogenic hormones (insulin plus cortisol plus prolactin) did not affect appreciably the uptake of L-glutamate.

Effect of ethanol/arrack on the lipid metabolism of mammary gland during pregnancy and lactation in rats.

Female rats were exposed to arrack (12.0 ml/kg body weight/day) and ethanol (4.0 g/kg body weight/day) before conception and throughout gestation and lactation. On 19th day of gestation and 21st day of lactation there was increase in the cholesterol phospholipids, triglycerides and free fatty acids in the mammary gland of rats administered arrack/ethanol in comparison with the controls. The lipoprotein lipase activity showed significant increase in the treated groups, in which the activity decreased on 21st day in comparison with 19th day. The absolute and relative weight of mammary gland also showed a significant decrease in ethanol/arrack treated group. The biochemical alterations produced in the mammary gland by arrack and its equivalent alcohol were different showing that non-alcoholic portion of arrack interferes with the toxicity induced by alcohol. Arrack was found to be a potent hyperlipidemic agent than ethanol.

Characterisation and starvation induced regulation of methionine uptake sites in mouse mammary gland.

The sites of methionine uptake by 10 day lactating mouse mammary gland were determined in vitro. Four modes of methionine entry characterised were: (i) A sodium-dependent, N-(methylamino) isobutyric acid (MeAIB)--sensitive system with a Vmax of 18.8 nmol/g cells/min (this mode of entry was similar to the A site in other tissues); (ii) A sodium-dependent, MeAIB--insensitive uptake system with a Vmax of 12.4 nmol/g cells/min); this mode of entry was inhibited by substrates preferred by ASC system); (iii) A sodium-independent, 2-amino-bicyclo heptane 2-carboxylic acid (BCH)-sensitive system L with a Vmax of 30 nmol/g cells/min; and (iv) A sodium-independent entry which was not inhibited by high concentrations of MeAIB or BCH. The Km value of each of the former three carrier mediated transport systems was 0.46 mM. Starvation of animals brought about important increase in the Vmax of the A system by 97% and that of ASC system by 1003% which was accompanied by similar increases in the Km values of these systems. These results show an adaptive regulation of these two sodium-dependent sites as a result of starvation.

Efeitos da metoclopramida sobre o aparelho genital de ratas virgens / Metoclopramide effects on female rats genital system

A metoclopramida é considerada um antagonista da dopamina. Uma vez que a dopamina inibe a liberaçäo de prolactina pela hipófise anterior é de se esperar que o uso da metoclopramida leve a um aumento dos níveis séricos de prolactina. O seu uso por longos períodos levaria ao aumento do volume das mamas, galactorréia e distúrbios menstruais. Procurando investigar os efeitos desta substânvia sobre os órgäos genitais femininos, utilizaram-se 30 ratos, fêmeas virgens, Wistar-Tecpar, com idade entre 83 e 90 dias e peso variando de 160 a 249 gramas, divididos em dois grupos de 15 animais cada. O grupo experimento recebeu metoclopramida na dose de 10mg/dia por via intraperitoneal e o grupo controle, soluçäo fisiológica de mesmo volume. As aferiçöes foram realizadas no oitavo, décimo sexto e vigésimo quarto dias, quando eram analisados: mamas, ovários e útero. Pode-se constatar que as glândulas mamárias apresentavam-se bem desenvolvidas nos animais com 16 e 24 dias de medicaçäo (p16 = 0,001 e p24 = 0,0003), mostrando maior concentraçäo de alvéolos e ductos. Estes continham secreçäo no seu interior, porém näo houve diferença significante entre os dois grupos. No ovário observou-se a predominância de folículos secundários e o útero mostrou endométrio com características proliferativa em todos os períodos estudados em ambos os grupos. Estes dados sugerem que a metoclopramida atua sobre a glândula mamária estimulando seu desenvolvimento, porém näo se pode constatar influência significante sobre o ovário e útero com esta dose, via de administraçäo e tempo de administraçäo, em ratas virgens

Diosgenin--a growth stimulator of mammary gland of ovariectomized mouse.

Estrogenic action of diosgenin on the mammary epithelium of ovariectomized (OVX) mouse has been reported. Diosgenin when administered (sc) at the dose levels of 20 and 40 mg/kg body weight for a period of 15 days stimulated the growth of mammary epithelium. This was indicated by the increase in DNA content, increase in number of ducts and appearance of terminal endbuds. There was a significant increase in the mammary development scores in the presence of diosgenin. Concomitant treatment of estrogen and diosgenin showed augmentation of estrogenic effect of diosgenin especially at the higher dose level (40 mg/kg body wt). Diosgenin showed a lack of progesterogenic action as was apparent from the absence of alveolar development even in the presence of exogenous estrogen.

Aspectos morfologicos e morfometricos de glandulas mamarias de ratas albinas tratadas com sulpiride / Morphological and morphometric aspects of mammary glands of albinic female rats treated with sulpiride

Procurou-se observar aspectos morfologicos e morfometricos das glandulas mamarias de ratas albinas tratadas com sulpiride, submetidas ou nao a ooforectomia. Tivemos como resultados da morfologia, no grupo de ratas na fase de estro e nas ooforectomizadas, tratadas ou nao pelo sulpiride, glandulas mamarias atrofiadas. Nas ratas apenas tratadas com sulpiride as glandulas mamarias apresentaram-se bem desenvolvidas, com alveolos contendo secrecao no seu interior. A proporcao de ductos e de alveolos mamarios se mostrou significantemente maior no grupo de ratas tratadas apenas com sulpiride.

Studies on hormonal modulation of asparagine-linked glycoprotein biosynthesis in explant cultures of rat mammary gland.

Glucosidase I has been purified to homogeneity and polyclonal antibodies against the enzyme have been prepared. The anti-glucosidase I antibodies recognized a single band of 85 kDa on western blot at a dilution as high as 1:2000 and also inhibited the enzyme activity, suggesting the specificity of the antibodies. Con A-Sepharose binding experiment indicates that this enzyme itself is a high mannose type N-linked glycoprotein. The increase in the electrophoretic mobility of 85 kDa band following digestion with endoglycosidase H and F strengthened this observation. The presence of any O-linked sugar attached covalently to glucosidase I could not be detected by binding assays with O-linkage specific biotinylated lectins. The studies on developmental regulation suggest that the synthesis of glucosidase I is modulated with the ontogeny of the gland. Lactogenic hormones, viz. insulin, hydrocortisone and prolactin, appeared to regulate the synthesis of glucosidase I. The possible role of these hormones in the overall regulation of protein N-glycosylation has been discussed.

Açäo da metoclopramida sobre a glândula mamária de ratas albinas em aleitamento ou em desmame precoce: estudo morfológico / Metoclopramide action on the mammary glands of albino rats in lactation or in early weaning: morphological study

Os autores realizaram, a nível de microscopia óptica, estudo morfológico das glândulas mamárias de ratas albinas tanto em aleitamento quanto daquelas submetidas a desmame precoce, tratadas ou näo com metoclopramida. Observaram que no grupo em aleitamento, tanto naquelas tratadas ou näo, os alvéolos e ductos apresentavam-se bem desenvolvidos, contendo secreçäo eosinófila no seu interior. Já no grupo submetido a desmame precoce, notaram predomínio de estroma em relaçäo ao parênquima, apresentando glândulas mamárias pouco desenvolvidas. No grupo tratado e submetido a desmame precoce, ocorreu equilíbrio entre o estroma e o parênquima, este último contendo secreçäo em sua luz. Neste último grupo, as mamárias apresentaram-se menos atrofiadas do que no grupo anterior

Nuclear phenotypical changes of human breast epithelial cells treated with carcinogens

Células epiteliais normales fueron obtenidas del tejido mamario de una paciente de 26 años en la cual se realizó una reducción mamoplástica. Las células fueron tratadas con los carcinógenos químicos N-nitro-N-metilurea (NMU), 4-nitroquinolina-N-oxido (NQO), o con 7,12-dimetil-benzantraceno (DMBA) en la fase logarítmica crescimento durante el primer pasaje en cultivo. Las células fueron analizadas a fin de detectar cambios nucleares fenotípicos tales como condensación de la cromatina, y cambios en el área nuclear. Tanto las células del grupo cocntrol como las tratadas exhibieron variaciones en condensación de la cromatina nuclear, que permitió clasificar los núcleos en dos tipos igualmente distribuidos: núcleos Tipo I, que eran pequeños, con cromatina finamente granular o filamentosa, y núcleos Tipo II, más grandes, con cromatina granular y un nucleolo prominente rodeado de cromatina condensada. Cada tipo nuclear fue subdividido en 5 subclases de acuerdo a variaciones en el área nuclear. El tratamiento con los carcinógenos cambió la frecuencia relativa de los tipos nucleares, con un aumento con los carcinógenos cambió la frecuencia relativa de los tipos nucleares, con un aumento de núcleos Tipo II y de aquéllos con mayor área nuclear. El tratamiento con NQO indujo el mayor cambio de frecuencia de núcleos Tipo I a Tipo II (del 50 al 80,5%), aumento del área nuclear y condensación de la cromatina. NMU y DMBA indujeron cambios similares, pero menos prominentes. Estos resultados permitieron concluir que el tratamiento in vitro de als células mamarias de esta paciente con carcinógenos químicos indujo cambios fenotípicos nucleares que podrían interpretarse como una expresión temprana de transformación celular maligna

Influence of sex steroids and prolactin on rat mammary gland.

The effect of sex steroids and prolactin on rat mammary glands. Estradiol-17 beta alone was found to increase the protein concentration significantly. Progesterone increased LDH and G-6-PD activities whereas Estradiol and Prolactin decreased LDH activity. G-6-PD activity was increased by estradiol and prolactin. Glycogen concentration was decreased by prolactin alone. Further, these hormones increased the percentage of total 'M' subunits and decreased total 'H' subunits of LDH. In general, sex steroids and prolactin increased glycogen utilisation and prepared the Mammary Gland or anaerobic metabolism.