Função luteal e luteólise em cadelas: aspectos morfo-funcionais
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Data
2004
Autores
Luz, Marcelo Rezende [UNESP]
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Universidade Estadual Paulista (Unesp)
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Os mecanismos luteotróficos e luteolíticos que controlam a função luteal em cadelas têm sido investigados. Este estudo avaliou as concentrações plasmáticas de PGFM e progesterona ao longo da gestação e do diestro, e do estradiol a partir do dia 40 da gestação ou diestro; a produção in vitro de PGF2α através de cultivos de explantes de endométrio, corpo lúteo e placenta, com ou sem estímulo por PDBu; a ocorrência de apoptose nas células luteais; e o envolvimento da enzima caspase-3 na luteólise em cadelas. Foram utilizadas 17 cadelas sem-raça-definida, divididas em dois grupos: diestro e gestação. Foi verificado que a queda das concentrações plasmáticas de progesterona em cadelas é um fenômeno lento e gradativo, que ocorreu a partir do terço inicial da gestação ou do diestro. As concentrações basais de progesterona foram atingidas nos dias 64 e 66 da gestação e diestro, respectivamente. Altas concentrações de PGFM e estradiol foram detectadas na segunda metade do diestro e da gestação. Ocorreu aumento progressivo de PGFM na segunda metade da gestação, e não no diestro, que culminou com um pico préparto. Os cultivos in vitro evidenciaram que o endométrio possui grande capacidade de produção de PGF2α, estimulado ou não por PDBu, superior aos explantes de corpo lúteo e de placenta, e mais pronunciado nos explantes de endométrio de cadelas gestantes comparados aos de cadelas em diestro. As análises histológicas por HE e CEC evidenciaram raras células apoptóticas no corpo lúteo das cadelas gestantes e em diestro, com células luteais íntegras detectadas nos corpos lúteos de cadelas no final da gestação, pós-parto imediato e aos 65 dias do diestro. Material sugestivo de corpus albicans foi evidenciado nos ovários oriundos das cadelas aos 75 e 85 dias do diestro. As concentrações de UAF/μg/ptn de caspase-3 não diferiram entre as... .
Luteotrophic and luteolytic mechanisms that control the luteal function in bitches are being investigated. This study evaluated the PGFM and progesterone plasma concentrations throughout pregnancy and diestrus, and plasma estradiol concentrations from day 40 of pregnancy or diestrus on; the in vitro production of PGF2α from explants of endometrium, corpus luteum and placenta cultures, with or without PDBu stimulation; the occurrence of apoptosis in the luteal cells; and the involvement of the enzyme caspase-3 in the luteolysis in bitches. Seventeen crossbred bitches, divided into 2 groups were used: diestrus and pregnancy. It was observed that the decrease of the plasma progesterone concentrations in bitches is a slow and gradual process, wich happened since the initial third of pregnancy or diestrus. The basal values of progesterone occurred at days 64 and 66 of pregnancy and diestrus, respectively. High plasma concentrations of PGFM and estradiol were detected at the second half of pregnancy, and not of diestrus, and culminate with a pre-partum peak. The in vitro cultures showed that endometrium has a big capacity of PGF2α production, stimulated or not by PDBu, and superior to corpus luteum or placenta explants, and also much more pronounced in the endometrium explants from pregnant compared to diestrus bitches. The histological analysis by HE and CEC showed rare apoptotic cells in the corpus luteum from pregnant and diestrus bitches, with intact luteal cells detected in corpora lutea from bitches in final pregnancy, immediate post-partum period and at 65 days of diestrus. Material suggestive of corpus albicans was evidenced in the ovaries of bitches on days 75 and 85 of diestrus. The concentrations of UAF/μg/ptn of caspase-3 did not differ between pregnant or diestrus bitches, and was also detected in the material suggestive of corpus albicans.
Luteotrophic and luteolytic mechanisms that control the luteal function in bitches are being investigated. This study evaluated the PGFM and progesterone plasma concentrations throughout pregnancy and diestrus, and plasma estradiol concentrations from day 40 of pregnancy or diestrus on; the in vitro production of PGF2α from explants of endometrium, corpus luteum and placenta cultures, with or without PDBu stimulation; the occurrence of apoptosis in the luteal cells; and the involvement of the enzyme caspase-3 in the luteolysis in bitches. Seventeen crossbred bitches, divided into 2 groups were used: diestrus and pregnancy. It was observed that the decrease of the plasma progesterone concentrations in bitches is a slow and gradual process, wich happened since the initial third of pregnancy or diestrus. The basal values of progesterone occurred at days 64 and 66 of pregnancy and diestrus, respectively. High plasma concentrations of PGFM and estradiol were detected at the second half of pregnancy, and not of diestrus, and culminate with a pre-partum peak. The in vitro cultures showed that endometrium has a big capacity of PGF2α production, stimulated or not by PDBu, and superior to corpus luteum or placenta explants, and also much more pronounced in the endometrium explants from pregnant compared to diestrus bitches. The histological analysis by HE and CEC showed rare apoptotic cells in the corpus luteum from pregnant and diestrus bitches, with intact luteal cells detected in corpora lutea from bitches in final pregnancy, immediate post-partum period and at 65 days of diestrus. Material suggestive of corpus albicans was evidenced in the ovaries of bitches on days 75 and 85 of diestrus. The concentrations of UAF/μg/ptn of caspase-3 did not differ between pregnant or diestrus bitches, and was also detected in the material suggestive of corpus albicans.
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LUZ, Marcelo Rezende. Função luteal e luteólise em cadelas: aspectos morfo-funcionais. 2004. 150 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, 2004.