Altered secretion of pregnancy-associated glycoproteins during gestation in bovine somatic clones.

in Theriogenology (2011), 76(6), 1006-1021

Somatic nuclear transfer (NT) in cattle is often accompanied by severe placental anomalies, hypertrophy, and hydrallantois, which induce a high rate of pregnancy losses throughout gestation. These ... [more ▼]

Somatic nuclear transfer (NT) in cattle is often accompanied by severe placental anomalies, hypertrophy, and hydrallantois, which induce a high rate of pregnancy losses throughout gestation. These placental deficits are associated with an abnormal increase of the maternal plasma levels of pregnancy-associated glycoprotein (PAG), produced by the trophoblastic binucleate cells (BNC) of the placenta. The objective of this study was to analyze the origin of the abnormally elevated PAG concentrations in the peripheral circulation of NT recipients during pathological pregnancies. Concentrations of PAG were measured both in maternal blood, in chorionic and cotyledonary tissular extracts from control recipients (after artificial insemination, AI, or in vitro fertilization, IVF) and clone recipients on Day 32, Day 62, and during the third trimester of gestation. Three different radioimmunoassay (RIA) systems were used. One homologous RIA for PSP60, similar to bovine PAG-1 (PAG(67kDa)), and two heterologous RIA with PAG(67kDa) as standard and tracer, and antisera anti-caprine PAG (AS#706 and AS#708). Circulating and tissular concentrations of bovine placental lactogen (bPL), a glycoprotein also produced by BNC, were determined by RIA at the same stages. The number of BNC in the placental tissues was determined by cell counting after immunostaining with anti PSP60 antibody on tissue sections from control and NT pregnancies. Maternal plasma PAG concentrations were not different among groups on Day 32, but they were significantly higher in NT than in control pregnancies on Day 62 with all three RIA and during the third trimester with two RIA (RIA-PSP60 and RIA with AS#708). Circulating bPL concentrations were undetectable on Days 32 and 62 and were not different in the third trimester between NT and control pregnancies. Tissular amounts of PAG on total proteins were not different between the two groups at all stages studied. No difference was determined in the percentage of PSP60-positive BNC in placental tissues between controls and NT on Day 62 and during the third trimester of pregnancy. Western blots of tissular extracts from placenta showed no major molecular weight changes of PAG in NT pregnancies compared to controls. No differences in maternal circulation concentrations or tissular content of bPL were observed between control and NT pregnancies. In conclusion, the specific increase of PAG in maternal plasma concentrations during abnormal NT pregnancies do not result from a higher proportion of BNC, or an increased protein expression of PAG and could be due to changes in the composition of terminal glycosylation which result into a clearance decrease of PAG from the circulation. [less ▲]

Utilisation répétée des gonadotropines exogènes dans le contrôle de la reproduction: justifications et effets secondaires potentiels

in Annales de Médecine Vétérinaire (1998), 142(2), 373-396

Gonadotropins of pituitary origin (follitropin -FSH-, lutropin -LH-, human menopausal gonadotropin -hMG) or trophoblastic origin (human chorionic gonadotropin - hCG- also called pregnant urine ... [more ▼]

Gonadotropins of pituitary origin (follitropin -FSH-, lutropin -LH-, human menopausal gonadotropin -hMG) or trophoblastic origin (human chorionic gonadotropin - hCG- also called pregnant urine gonadotropin -pU-, equine chorionic gonadotropin -eCG- also called pregnant mare serum gonadotropin -PMSG-) are largely used to treat infertility or to better control sexuality in various species of mammals: bovine, canine, caprine, equine, feline, human,ovine, porcine, rabbit, ... This manuscript reports the discovery of these molecules, describes their biochemical characteristics and gives the main indications (e.g. oestrus induction and synchronization, ovulation, superovulation, fertility improvement, anoestrus treatment, receptivity induction) in animals and human. Litterature data reporting on effects and possible side effects of their repeated use are presented. Due to slight differences in amino acids sequences, carbohydrates contents and tridimentionnal structures, repeated use of exogeneous gonadotropins may induce immunological reactions leading to non specific reactions and lower biological response. A reflection concludes this revue, pointing out the positive influence of the philogenetic distance existing between the species origin of the gonadotropin (human or equine) and the treated one, on the intensity of the immune reaction. [less ▲]