Table 3.
The –log EC50 values (M) ±SEM for norepinephrine, serotonin, ergotamine, and tall fescue seed extract in umbilical and uterine arteries collected from ewes fed endophyte-infected or endophyte-free seed from day 35 to day 133 of gestation or switched on day 861
| Myograph treatment | Seed treatment2 | P-value3 | |||
|---|---|---|---|---|---|
| E–E– | E+E– | E–E+ | E+E+ | ||
| Umbilical artery4 | |||||
| Serotonin | 4.37 ± 0.11 | 4.35 ± 0.11 | 4.33 ± 0.12 | 4.14 ± 0.12 | 0.52 |
| Ergotamine | 5.56 ± 0.11 | 5.55 ± 0.11 | 5.34 ± 0.14 | 5.59 ± 0.11 | 0.56 |
| Ergovaline5 | 5.25 ± 0.08 | 5.33 ± 0.08 | 5.09 ± 0.08 | 5.16 ± 0.08 | 0.19 |
| Uterine artery | |||||
| Norepinephrine | 4.24 ± 0.12 | 4.45 ± 0.13 | 4.48 ± 0.13 | 4.42 ± 0.12 | 0.53 |
| Serotonin | 4.24 ± 0.24 | 4.34 ± 0.24 | 4.51 ± 0.36 | 4.83 ± 0.28 | 0.45 |
| Ergotamine | 5.62a ± 0.16 | 5.46a ± 0.16 | 4.67b ± 0.16 | 5.19a ± 0.16 | 0.002 |
| Ergovaline5 | 4.88 ± 0.24 | 5.01 ± 0.24 | 5.27 ± 0.28 | 5.27 ± 0.28 | 0.65 |
1Used the three parameter nonlinear equation to fit line to data. Fifty percent of the effective concentration (EC50) is a measure of the potency of an agonist and is the concentration where 50% of the contractile response is achieved.
2Endophyte-infected (E+) and endophyte-free (E–) tall fescue seed.
3The probability of seed treatment differing with row.
4The EC50 values for norepinephrine response in umbilical artery were not obtained due to a lack of convergence because of negligible responses to this agonist.
5A tall fescue seed extract was used to supply ergovaline and the extract was diluted based on ergovaline concentrations.
abMeans within a row not sharing like superscripts differ (P < 0.05).