Isolation of a hypothalamic peptide with TRF (thyreotrophin releasing factor) activityin vitro

In VitroSecretion of Thyrotropin (TSH): Stimulation by a Hypothalamic Peptide (TRF)

“…Schreiber et al (13) also have reported on the in vitro TSH-releasing activity of a highly purified material obtained from extracts of beef hypothalamus; it will be of interest to ascertain whether or not the material purified by these authors is similar to the active substance in the TRF fraction purified by us here. It is somewhat puzzling that the crude material used here as TRF should be active at the 1.0 jug level in our in vitro system, whereas Schreiber et al use 90.0 ixg and 200.0 jug of their highly purified material to observe any effect in vitro.…”

“…It is somewhat puzzling that the crude material used here as TRF should be active at the 1.0 jug level in our in vitro system, whereas Schreiber et al use 90.0 ixg and 200.0 jug of their highly purified material to observe any effect in vitro. Recently, Odell (13) has reported that hypothalamic tissues, when incubated with anterior pituitary fragments, would increase the amount of TSH activity measured in the incubate. It is difficult to appreciate the significance of this report at the moment, as there is no mathematically valid evidence of true regression of effect over log dose in the experiments reporting effects (on TSH release) of incubation with hypothalamic fragments.…”

Thyroid-stimulating Hormone Response to Synthetic Thyrotrophin-releasing Hormone in Man

“…The identification of the factor was first claimed by Shibusawa et al (1956), but this work did not receive wide acceptance. Harris (1963), Schreiber et al (1962, and Reichlin (1964) observed that extracts of median eminence increased thyroid function in mice and rabbits. More convincing evidence for the existence of such a factor was produced by Guillemin et al (1962Guillemin et al ( , 1963Guillemin et al ( , 1965 and Schally et al (1966aSchally et al ( , 1966bSchally et al ( , 1966c, who recovered and purified a thyrotrophin-releasing factor and other hypothalamic releasing substances from fragments of porcine, ovine, bovine, and human hypothalamic tissue.…”