Growth hormone increases DNA damage in ovarian follicles and macrophage infiltration in the ovaries.

Evidence points to an important role of the growth hormone (GH) in the aging process and longevity. GH-deficient mice are smaller, live longer than normal littermates, and females have an increased ovarian reserve. The aim of the study was to evaluate the role of GH in the ovarian reserve by evaluating DNA damage, macrophage infiltration, and granulosa cell number in primordial and primary follicles. Experiment 1 used GH-deficient Ames dwarf mice (df/df, n = 12) and their normal littermates (N/df, n = 12), receiving GH or saline injections. Experiment 2 included transgenic mice overexpressing bovine GH (bGH) (n = 6) and normal mice (N, n = 6). DNA damage (anti-γH2AX) and macrophage counting (anti-CD68) were evaluated by immunofluorescence. Female df/df mice had lower γH2AX foci intensity in both oocytes and granulosa cells of primordial and primary follicles (p < 0.05), indicating fewer DNA double-strand breaks (DSBs). GH treatment increased DSBs in both df/df and N/df mice. Inversely, bGH mice had a higher quantity of DSBs in both oocytes and granulosa cells of primordial and primary follicles (p < 0.05). Df/df mice showed ovarian tissue with less macrophage infiltration than N/df mice (p < 0.05) and GH treatment increased macrophage infiltration (p < 0.05). In contrast, bGH mice had ovarian tissue with more macrophage infiltration compared to normal mice (p < 0.05). The current study shows that GH increases DNA DSBs in oocytes and granulosa cells and raises macrophage infiltration in the ovaries, pointing to the role of the GH/IGF-I axis in maintenance of oocyte DNA integrity and ovarian macrophage infiltration in mice.

Histological description of Cerdocyon thous (Linnaeus, 1766) respiratory system / Descrição histológica do sistema respiratório de Cerdocyon thous (Linnaeus, 1766)

The massive agricultural expansion converted the Cerdocyon thous, a South American native predator, in vulnerable specie. Basic data, such as histological description, are important to raise awareness on animal species, helping on preservation strategies. Considering the difficult in obtain samples, as the euthanasia of wild animals for this purpose is not allowed, data on histology are very scarce or inexistent. The objective of this paper was to provide a detailed histological description of the trachea and bronchial tree of the crab-eating fox Cerdocyon thous (Linnaeus, 1766). The specimens (one adult male and one adult female) used were provided by the Federal University of Pelotas (Pelotas, RS, Brazil) Rehabilitation Center of Wild Fauna (NURFS). Tissue samples were fixed in 10% formalin and included in paraffin. After slicing, samples were stained with HE (hematoxylin and eosin), PAS (periodic acid-Schiff) and resorcin fuchsin. Trachea had an average diameter of 7.87mm, and approximately 57% of the mucosa ciliated pseudo-stratified columnar epithelium was composed of goblet cells, mostly in the dorsal region. Bronchia and bronchioles had a mucosal fold with higher number of goblet cells. Using all these techniques there is no great remarkable differences from C. thous trachea and lung, when compared with the previous described structures for carnivores and most mammals, except for the goblet cells "regionalization". Described results are important to understand the animal physiological and behavioral habits, allowing the development of preservation and protection strategies.(AU)

A expansão agrícola maciça tornou o Cerdocyon thous, um predador nativo sul-americano, vulnerável. Dados básicos, tais como descrição histológica, são importantes para aumentar o conhecimento sobre as espécies, ajudando nas estratégias de preservação. A eutanásia de animais selvagens para a coleta de amostras não é permitida, por isso os dados sobre a histologia são muito escassos ou inexistentes. O objetivo deste trabalho foi de fornecer uma descrição histológica detalhada da traqueia e árvore brônquica do cachorro do mato Cerdocyon thous (Linnaeus 1766). Os espécimes (um macho e uma fêmea adultos) utilizados foram fornecidos pela Universidade Federal de Pelotas (Pelotas, RS, Brasil), Centro de Reabilitação da Fauna (NURFS). As amostras de tecido foram fixadas em formalina a 10% e incluídas em parafina. Após o corte, as amostras foram coradas com HE (hematoxilina e eosina), PAS (ácido periódico de Schiff) e resorcina fucsina. A traqueia tinha um diâmetro médio de 7,87 milímetros e aproximadamente 57% do diâmetro do epitélio colunar pseudo-estratificado ciliado da mucosa composto por células caliciformes, principalmente na região dorsal do órgão. Os brônquios e bronquíolos apresentaram cararísticas similares aos outros animais, contudo aparenta ter maior número de células caliciformes. Usando distintas técnicas de coloração, observou-se que não há diferenças notáveis da traqueia e do pulmão de C. thous quando comparados com os dados para carnívoros e para a maioria dos mamíferos, exceto a regionalização de células caliciformes. Os resultados descritos são importantes para compreender a fisiologia dos animais e hábitos comportamentais, permitindo o desenvolvimento de estratégias de preservação e proteção.(AU)