Rl. Lloyd et al., Antidepressant effects of thyrotropin-releasing hormone analogues using a rodent model of depression, PHARM BIO B, 70(1), 2001, pp. 15-22
The antidepressant potential of two naturally occurring analogues of thyrot
ropin-releasing hormone (TRH), pGLU-GLU-PRO-NH2 (EEP) and pGLU-PHE-PRO-NH2
(EFP), were examined using a rodent model of antidepressant efficacy. The P
orsolt Swim Test was used to assay the antidepressant proper-ties of these
two peptides. Both analogues of TRH produced significant antidepressant eff
ects, with EEP producing the stronger response. No effect of EEP upon triio
dothyronine (T-3) was observed at the dosage used. EFP, which has previousl
y been demonstrated to crossreact with the TRH receptor, significantly incr
eased serum T-3. Since an effect upon T-3 was only observed in the weaker o
f the two compounds, these data suggest that the behavioral effect of EEP w
as not secondary to stimulation of thyroid hormone. Additionally, the diffe
rential behavioral response to the two compounds suggests a degree of seque
nce specificity in the ability of TRH-like tripeptides to produce an antide
pressant effect. (C) 2001 Elsevier Science Inc. All rights reserved.