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Summary. In Exp. 1, only medium from cultures containing conceptus tissue had antiviral activity (P < 0·05). Addition of Day-15 pregnant endometrium or Day-14 cyclic uterine flush proteins to cultures containing 200 mg conceptus tissue decreased antiviral activity (conceptus × endometrial protein interaction, P < 0·06). Effects of endometrium (− 54%) and uterine flush proteins (− 40%) on antiviral activity of conceptus cultures did not differ from each other (P > 0·10). In Exp. 2, antiviral activity was only detected in cultures containing conceptus tissue (P < 0·06). The amount of antiviral activity in cultures of Day-15 conceptus tissue was not influenced differently (P > 0·10) by culture in medium conditioned by endometrium from Day 10 or Day 12 of pregnancy. However, antiviral activity was undetectable in medium conditioned by endometrium from one of the Day-12 gilts. In Exp. 3, antiviral activity was present in medium from only 1 of 3 cultures from Day-12 gilts when assayed unfrozen. Antiviral activity was lower (P < 0·01) in cultures of conceptuses from Day 12 than Day 14 of pregnancy; however, antiviral activity increased quadratically (P < 0·05) when cultures contained 0, 0·01, 0·1 and 1·0 units/ml aprotinin, respectively. Freezing and thawing culture medium did not reduce (P > 0·10) antiviral activity compared to medium assayed unfrozen (1438 vs 1354 units/ml, respectively). These results suggest a regulatory influence of the endometrium on secretion of antiviral proteins by pig conceptuses in vitro.

Keywords: pig; pregnancy; conceptus; interferon; endometrium; proteolysis

Summary. In Exp. 1, antiviral activity was detected in Day-15 pregnant uterine flushings (6222 ± 2167 units/ml) and in conceptus culture medium collected at 0, 1, 2, 4, 8, 16, 24, 32, 40, and 48 h (95, 375, 650, 1216, 1600, 2100, 2017, 2083, 3500 and 5000 units/ml, respectively; R² = 0·81, P < 0·01; y = 190·0 + 252·7x − 11·2x ² + 0·2x ³. In Exp. 2, antiviral activity of Day-15 conceptus culture medium was reduced 99% after boiling for 20 min (P < 0·01) and, after 18 h dialysis (6000–8000 M _r cut-off), 100% of the activity was in the retentate. In Exp. 3, antiviral activity was not detected in cultures of conceptuses from Days 10 and 11 and activity was maximal for Day 14 and Day 15 conceptuses (2100 and 2083 units/ml, respectively). Effects of day were best described by a quadratic regression equation (y = 17 652 − 3263x + 150x ²; R² = 0·55, P < 0·01). In Exp. 4, changes in antiviral activity detected in uterine flushings from pregnant gilts on Days 8, 10, 11, 12, 14 and 15 (1·3, 0, 6·7, 63·3, 580 and 1663 units/ml, respectively) were described by the equation y = −20 743 + 6189x − 606x ² + 20x ³ (R² = 0·85, P < 0·01). In Exp. 5, low antiviral activities (5–30 units/ml) were detected in all plasma samples collected from the uterine artery and uterine vein of pregnant and cyclic gilts, but values were not significantly influenced by pregnancy status, day or site of collection.

These results indicate that proteins with antiviral activity are secreted by pig conceptuses after Day 10 of pregnancy with highest activities on Days 14 and 15. The presence of conceptuses does not influence antiviral activity in the uterine vasculature.

Keywords: pig; pregnancy; conceptus; protein; interferon

The purpose of this study was to evaluate the intragestational role of ghrelin in offspring development and reproductive programming in a mouse model of ghrelin imbalance during pregnancy. Female mice were injected with ghrelin (supraphysiological levels: 4 nmol/animal/day), antagonist (endogenous ghrelin inhibition with (D-Lys₃)GHRP-6, 6 nmol/animal/day) or vehicle (control = normal ghrelin levels) throughout the pregnancy. Parameters evaluated in litters were growth, physical, neurobiological and sexual development and, at adulthood, reproductive function. Litter size and initial weight did not vary between treatments. Male pups from dams treated with ghrelin showed higher body weight increase until adulthood (31.7 ± 0.8 vs control = 29.7 ± 0.7, n = 11–14 litters/treatment; P < 0.05). Postnatal physical and neurobiological development was not modified by treatments. The antagonist accelerated male puberty onset, evidenced as earlier testis descent and increased relative testicular weight (antagonist = 0.5 ± 0.0% vs ghrelin = 0.4 ± 0.0% and control = 0.4 ± 0.0%, n = 5–10 litters/treatment; P < 0.05). At adulthood, these males exhibited lower relative testicular weight and reduced sperm motility (63.9 ± 3.6% vs control = 70.9 ± 3.3 and ghrelin = 75.6 ± 3.0, n = 13–15 animals; P < 0.05), without changes in plasma testosterone or fertility. Female pups intragestationally exposed to the antagonist showed earlier vaginal opening (statistically significant only at Day 25) and higher ovarian volume (antagonist = 1085.7 ± 64.0 mm³ vs ghrelin = 663.3 ± 102.8 mm³ and control = 512.3 ± 116.4 mm³; n = 4–6 animals/treatment; P < 0.05), indicating earlier sexual maturation. At adulthood, these females and those exposed to ghrelin showed a tendency to higher percentages of embryo loss and/or foetal atrophy. In conclusion, ghrelin participates in reproductive foetal programming: alterations in ghrelin activity during pregnancy modified body weight increase and anticipated puberty onset, exerting (or tending to) negative effects on adult reproductive function.