Chronic intracerebroventricular TLQP-21 delivery does not modulate the GH/IGF-1-axis and muscle strength in mice

Objective: Biallelic ablation of VGF determines a dwarf phenotype. VGF precursor protein encodes for different biologically active peptides none of which has been related to growth or muscular abnormalities. Here we present the first attempt to fill this gap. We tested the hypothesis that a recently identified VGF-derived peptide, TLQP-21, shown to centrally modulate metabolic functions, could also modulate growth hormone (GH)-axis and muscle strength. Design: Adult male mice were chronically icv injected with TLQP-21 (15 μg/day for 14 days). Physiological, molecular and behavioral parameters related to the GH/IGF-1-axis were investigated. Results: Except for a reduction in the soleus weight, TLQP-21 did not affect GH/IGF-1-axis mediators, muscle strength and muscle weight. Conclusions: Results collected exclude a role for TLQP-21 in modulating the GH/IGF1-axis and muscle functions. VGF-derived peptides involved in the dwarf phenotype of VGF-/- mice have to be identified yet.