Ultrasonographic findings of the mammary gland, liver, gallbladder, spleen, and kidneys in transgenic goats for hG-CSF during induced lactation

Abstract

In transgenic murine models, the study of certain organs or tissues can be performed after euthanasia of some specimens. However, this practice may not be economically feasible when applied to livestock such as transgenic goats. It is necessary to use minimally invasive methods to perform in vivo studies of organs that may be affected by disorders related to the activity of the transgene, particularly during milk production, when the recombinant protein is secreted. The aim of this study was to describe ultrasonographic findings of the liver, gallbladder, spleen, kidneys, and mammary glands in transgenic goats for evaluating the effect of human granulocyte-colony stimulating factor (hG-CSF) expression in milk during induced lactation. Six female Canindé goats-three transgenic (T) and three non-transgenic (NT)-were subjected to hormone therapy to induce lactation; ultrasonographic examinations of the liver, gallbladder, spleen, kidneys, and mammary gland were performed during both the hormonal therapy and the lactation period at different intervals depending on the organ being examined. On Day 16 (Day 1 = hormonal therapy initiation), all goats were lactating and presented healthy mammary glands, characterized by echogenic parenchyma showing a granular echotexture. Transgenic and nontransgenic goats were compared on the basis of measurements and ultrasound images obtained from each organ. No differences between T and NT animals were observed in the examined area for the liver, gallbladder, spleen, and kidneys. Liver and renal echogenicity and appearance of gallbladder and portal and hepatic veins were similar in all females. Ultrasonographic findings of the mammary gland, liver, gallbladder, spleen, and kidneys in transgenic goats did not show any difference from those in nontransgenic goats.Thus, these results suggest that the presence and expression of the transgene had no effect on the ultrasonographic findings of mammary gland and abdominal organs in the transgenic goats. Moreover, the findings shows that ultrasonography is a useful screening tool for clinical examination ResumoEm camundongos transgênicos, o estudo de certos órgãos ou tecidos pode ser viabilizado por meio da eutanásia de alguns exemplares. Entretanto, esta prática pode não ser economicamente viável quando aplicada a animais de produção, como caprinos transgênicos. É necessário utilizar métodos minimamente invasivos para estudar in vivo os órgãos que podem estar envolvidos em desordens relacionadas à atividade do transgene, principalmente durante a produção de leite, quando a proteína recombinante é secretada. O objetivo deste estudo foi descrever as características ultrassonográficas de fígado, vesícula biliar, baço, rins e glândula mamária de caprinos transgênicos expressando o fator estimulante de colônias de granulócitos humano (hG-CSF) no leite, durante lactação induzida. Seis fêmeas caprinas da raça Canindé: três não transgênicas (NT) e três transgênicas (T) foram submetidas a tratamento hormonal para indução da lactação; os exa...