| This experiment was conducted to determine the effect of incubation of Artemia nauplii with steroids prior to the first feeding instar II stage of Artemia development. Decapsulated Artemia cysts were incubated at a concentration of 3 g cysts/L in hatching media (1 L seawater at 1.030 SG, 0.08 g highly unsaturated fatty acid supplement) and either 20 mg 17beta-estradiol (E2) or 17alpha-methyldihydrotestosterone (MDHT) dissolved in 3 mL 70% ethyl alcohol or ethyl alcohol alone (control). Cysts were cultivated at 18--20°C for 24h. Nauplii were collected by filtering culture media, and were rinsed in 1 L fresh water. Artemia cultivated in control media contained 0.07 +/- 0.01 ng E 2/mg dry weight, and E2-treated Artemia contained 461 +/- 40 ng E2/mg dry weight (p < .0001). MDHT treated Artemia contained 546 +/- 31 pg/mg dry weight and controls were below the level of detection (4pg/mL; p < .0001).;This experiment evaluated the effect of Gram-positive peptidoglycan (PTG) challenge on reproductive performance of ewes. On d 5 post-breeding, ewes were injected I.V. with saline or 15, 30, or 60 mug/kg of sonicated PTG (Streptococcus pyogenes). Each dose of PTG induced fever. Pregnancy rate differed with treatment (p < .01), but was not correlated with incidence of fever. Neither mean nor profile of E 2 differed with treatment (p > .05). Mean and profile of P4 was lower in all treated than in control ewes (p < 0.01). Patterns of LH pulses did not differ; mean LH (ng/mL) was lower in ewes treated with 0, 15, or 30 mug/kg than in ewes treated with 60 mug/kg (p < 0.01). The pattern of cortisol secretion was biphasic and increased in all treated ewes (p < 0.01); mean cortisol was higher in treated than in control (p < 0.01). Maintenance of pregnancy was reduced in ewes with high concentrations of PGFM as compared to ewes with low concentrations of PGFM (p < 0.05). |
