Summary. The bactericidal and phagocytic activities of blood neutrophils suspended in uterine washings and the mobilization of neutrophils into the uterine lumen were studied in ovariectomized mares receiving oestradiol benzoate (N = 4), progesterone (N = 4) or oily vehicle (N = 4). Uterine lavage was performed sequentially up to 144 h after induction of endometritis by intrauterine infusion of glycogen (1%). There was no significant difference between the 3 groups in speed of mobilization of neutrophils into the uterus in the first 6 h after infusion but there were significantly more uterine luminal neutrophils in progesterone-treated than in oestradiol-treated mares by 24 h after infusion (P < 0·01). Uterine washings collected from progesterone-treated mares at 0, 24 and 144 h were significantly worse at promoting bactericidal activity by neutrophils than washings from oestradiol-treated and control mares (P < 0·001). In oestrogen-treated and control mares bactericidal activity had increased by 144 h but in progesterone-treated mares bactericidal activity remained low. Neither treatment nor time affected the ability of washings to opsonize yeast blastospores. Elevated concentrations of progesterone in plasma were therefore associated with decreased bactericidal activity of neutrophils suspended in uterine washings but the generation of C3b in washings did not appear to be affected by hormone treatment.
E. D. Watson, C. R. Stokes, J. S. E. David and F. J. Bourne
Jordanna S Master, George A Thouas, Alexandra J Harvey, John R Sheedy, Natalie J Hannan, David K Gardner and Mary E Wlodek
Low birth weight is associated with an increased risk for adult disease development with recent studies highlighting transmission to subsequent generations. However, the mechanisms and timing of programming of disease transmission to the next generation remain unknown. The aim of this study was to examine the effects of low birth weight and advanced maternal age on second-generation preimplantation blastocysts. Uteroplacental insufficiency or sham surgery was performed in late-gestation WKY pregnant rats, giving rise to first-generation (F1) restricted (born small) and control offspring respectively. F1 control and restricted females, at 4 or 12 months of age, were naturally mated with normal males. Second-generation (F2) blastocysts from restricted females displayed reduced expression of genes related to growth compared with F2 control (P<0.05). Following 24 h culture, F2 restricted blastocysts had accelerated development, with increased total cell number, a result of increased trophectoderm cells compared with control (P<0.05). There were alterations in carbohydrate and serine utilisation in F2 restricted blastocysts and F2 restricted outgrowths from 4-month-old females respectively (P<0.05). F2 blastocysts from aged restricted females were developmentally delayed at retrieval, with reduced total cell number attributable to reduced trophectoderm number with changes in carbohydrate utilisation (P<0.05). Advanced maternal age resulted in alterations in a number of amino acids in media obtained from F2 blastocyst outgrowths (P<0.05). These findings demonstrate that growth restriction and advanced maternal age can alter F2 preimplantation embryo physiology and the subsequent offspring growth.