Data/hora: 17/05/2024 05:28:54

Biblioteca(s): | Embrapa Caprinos e Ovinos.
Data corrente: | 23/03/2005
Data da última atualização: | 23/03/2005
Autoria: | MAJEWSKI, A. C.; HANSEN, P. J.
Título: | Progesterone allows survival of xenografts transplanted in the sheep uterus.
Ano de publicação: | 2000
Fonte/Imprenta: | Theriogenology, v. 53, n. 1, p. 285, 2000.
Idioma: | Inglês
Notas: | Edição de proceedings Annual Conference of the International Embryo Transfer Society, Maastricht, The Netherlands, jan. 2000.

Conteúdo:

Among its many actions to maintain pregnancy, progesterone is believed to down- regulate irnrnune responses in the uterus and prevent maternal immunological destruction of the alIogenic conseptus. Here, we show that progesterone aIlows the survival of a xenotransplant placed in the uterine lumen. The transplant was a mouse hybridoma cell tine that produces an antibody to spinach BiP, a member of the heat shock protein 70 family. This cell tine was chosen because the antibody does not react with sheep peripheral blood cells. Ten ewes were bilaterally ovariectomized and ligatures were placed around each uterine bom. After >30 d, ewes were injected daily for 30 d with either vehicle or 50 mg progesterone. Reproductive tracts were then exposed, one uterine bom was injected with 1 x 107 hybridoma cells suspended in phosphate-buffered saline (PBS), and the other bom received PBS. Hormonal treatments continued for another 14 d. Reproductive tracts were then removed and hybridoma cells were identified via indirect FITC-labeling using a monoclonal antibody to the hybridoma MHC class I haplotype (H2-Kd). 
The least-squares mean for number ofhybridoma cells recovered from ewes injected with vehicle was 0.0 for the PBS bom (hybridoma cells were recovered from 0/5 ewes) and 6600 for the hybridoma-injected bom (hybridoma cells were recovered from 1/5 ewes). In comparison. the least-squares man for number of hybridoma cells recovered from ewes injected with progesterone was 443,500 for the PBS bom (hybridoma cells were recovered from 2/5 ewes; in the ewes with hybridoma cells, the ligatures were patent) and 8,746,000 cells from the hybridoma-injected bom (hybridoma cells were recovered from 3/4 ewes; cells were 10st during processing for the 5th ewe and were not examined). Cell number was affected by progesterone treatment (P<0.02) and the progesterone x bom interaction (P<0.05). Using chi-square analysis, progesterone treatment affected the proportion of hybridoma-injected horns with recovered hybridoma cells (P<0.10). Overall, hybridoma cells were recovered from 1/5 vehicle-treated ewes and 4/5 progesterone-treated ewes (by chi-square analysis, P=0.06). These results demonstrate that progesterone can inhibit uterine tissue graft rejection responses sufficiently to aIlow survival of xenograft tissue. This suggests that the immunosuppressive action of progesterone contributes to the survival of the aIlogenic conceptus. The hybridoma model should prove useful in identifying the mechanism by which progesterone reguiates uterine irnrnune function.

Thesagro: | Endocrinologia; Ovino; Progesterona; Reprodução Animal; Sobrevivência; Útero.
Categoria do assunto: | --
Registro original: | Embrapa Caprinos e Ovinos (CNPC)
Exemplares: | CNPC - (17570-1) - ADC - AP - -- -  -  - v.53,p.285 - DIS