Morphology and alfa-SMA, F-actin and JC1 protein expression in the mammary gland of goats in early hormonal lactation

ABSTRACT

Background: Mammary remodeling is determined by a combination of cell differentiation, proliferation and programmeddeath controlled not only by systemic hormones, but also by proteins produced either in the stromal or in the epithelialcompartments. However, few works were undertaken to use phenotypic markers for cellular components of the lactatingcaprine mammary gland and to determine structural–functional relationships. Thus, the aim of this research was to evaluate the morphology and α-SMA, F-actin and JC1 protein expression in the mammary gland of Canindé goats in earlyhormonal lactation.Materials, Methods & Results: Fourteen 2 years old female Canindé goats were used and distributed into two groups nonlactating (n = 4) and lactating animals (n = 10). Lactation was induced by using estrogen, progesterone and prednisoloneaccording to previous protocol. All subjects were housed indoors and had four hours of daily access to solarium. Mammarygland biopsies were obtained at days 5 (D5) and 26 (D26) of the early stage of lactation and were assessed by histologicaland immunohistochemical analysis. The microstructure of mammary gland in lactating goats was analyzed by conventionalhistologic techniques. Immunohistochemistry was used by identify α-SMA in myoepithelial cells and JC1 in epithelialcells. α-SMA and F-actin expression were assessed by confocal microscopy. Concerning microscopic features, the alveolistructure was evaluated in respect to number, size and cell population. The structural units of the lactating mammary glandconsisted of variably shaped lobules. When comparing to lactating tissue, sections of the non-lactating mammary glandshowed a lower number and size of alveoli, separated by wide connective tissue. Lactating tissues demonstrated numerousand well-developed alveoli, separated by thin trabeculae of connective tissue. In relation to lactating goats, no difference (P> 0.05)...(AU)