Table 2.

LOAELs and Efficacies for Pyrazine Derivatives in the Oviductal Assays

LOAELs (M)a				Efficacies (%)b,c
Ciliary Beat Frequency	Oocyte Pickup Rate	Contraction Rate	Chemical	Ciliary Beat Frequency	Oocyte Pickup Rate	Contraction Rate
10-12	10-11	10-9	pyrazine	25	29	40
10-12	10-11	10-11	2-methylpyrazine	11*	43*	61**
10-12	10-11	10-12	2-ethylpyrazine	3**	45*	38
10-8	10-11	10-9	2,5-dimethylpyrazine	34	10*	40
10-6	10-9	10-7	2,6-dimethylpyrazine	5**	3**	85***
10-9	10-10	10-9	2,3,5-trimethylpyrazine	18	10*	58**
10-9	10-12	10-12	2-methoxy-3-methylpyrazine	18	13*	17**

^a LOAEL is lowest observable adverse effect level ^b Efficacy is the mean percentage of inhibition at the LOAEL ^c Student's t-Test was performed on efficacies comparing each chemical back to pyrazine for each bioassay. * p < 0.05; ** p < 0.01; *** p < 0.001.