The relative potencies of TRH analogs in provoking a shaking response in rats were determined. Bilateral administration of 0.011-2.0 μg TRH analog into the periaqueductal-fourth ventricular spaces of the barbiturate-anesthetized rat showed that N3im-methyl TRH was approximately 10X more potent than TRH, wherease N1im-methyl TRH was approximately 10X less potent than TRH. These results indicate that the potencies of the TRH analogs in inducing shaking parallel their thyrotropin-releasing activities.
- N-and N-methyl TRH
- Shaking in rats
- Thyrotropin-releasing hormone (TRH)