RESUMO
Objective To observe the effects of malt extract on prolactin expression and morphology of mammary tissue in hyperprolactinemia rats. Methods Metoclopramide hydrochloride was injected subcutaneously to establish hyperprolactinemia model. Sixty rats were divided into normal control group, model control group, bromocriptine group, high-dose, middle-dose and low-dose malt extract groups. Except normal control group, hyperprolactinemia model was established in the other groups. Bromocriptine (0. 389 mg·kg-1 ·d-1 ) was given to bromocriptine group. Malt extract (7. 98, 15. 96 and 31. 92 g·kg-1 ·d-1 ) was administered in low-dose, middle-dose and high-dose malt extract groups. Equal volume of purified water was given to normal control group and model control group. After 30 days of administration, PRL positive cell number of rat hypophysis was counted. RT-PCR was used to measure hypophysis PRL mRNA expression, and morphology of mammary tissues was observed by immunohistochemical method. Results PRL positive cell number was (2. 4±0. 3), (21. 7±0. 8), (3. 8± 0. 5), (4. 5±0. 4), (6. 7±0. 5) and (15. 8±1. 2) in normal control group, model control group, bromocriptine group, high-dose, middle-dose and low-dose malt extract groups. PRL mRNA expression level was (0. 31±0. 02), (1. 58±0. 06), (0. 45± 0. 04), (0. 49±0. 03), (0. 61±0. 04), and (0. 95±0. 09), respectively. As compared with normal control group, hypophysis PRL positive cell number and PRL mRNA expression level of high-dose and middle-dose malt extract group were increased significantly (P<0. 01), and hyperplasia of mammary glands appeared. As compared with model control group, hypophysis PRL positive cell number and PRL mRNA expression level of high-dose and middle-dose malt extract group was decreased significantly (P<0. 01), and hyperplasia of mammary glands was alleviated obviously. Conclusion Malt extract can effectively treat hyperprolactinemia and inhibit hyperplasia of mammary glands through significantly decreasing the expression of hypophysis prolactin in hyperprolactinemia rats.
RESUMO
Cows infected with Escherichia (E.) coli usually experience severe clinical symptoms, including damage to mammary tissues, reduced milk yield, and altered milk composition. In order to investigate the host response to E. coli infection and discover novel markers for mastitis treatment, mammary tissue samples were collected from healthy cows and bovines with naturally occurring severe E. coli mastitis. Changes of mammary tissue proteins were examined using two-dimensional gel electrophoresis and label-free proteomic approaches. A total of 95 differentially expressed proteins were identified. Of these, 56 proteins were categorized according to molecular function, cellular component, and biological processes. The most frequent biological processes influenced by the proteins were response to stress, transport, and establishment of localization. Furthermore, a network analysis of the proteins with altered expression in mammary tissues demonstrated that these factors are predominantly involved with binding and structural molecule activities. Vimentin and alpha-enolase were central "functional hubs" in the network. Based on results from the present study, disease-induced alterations of protein expression in mammary glands and potential markers for the effective treatment of E. coli mastitis were identified. These data have also helped elucidate defense mechanisms that protect the mammary glands and promote the pathogenesis of E. coli mastitis.