Study wrapper · #556
Intranasal Delivery of a Ghrelin Mimetic Engages the Brain Ghrelin Signaling System in Mice.
Editor's note
This mouse study administers GHRP-6 as an active compound and is directly relevant to how it might reach the brain. Comparing intranasal ghrelin, GHRP-6 and MK-0677, researchers reported that only GHRP-6 (5 mg/kg) increased food intake without adverse signs, activated appetite-related arcuate-nucleus neurons (shown by Fos mapping and RNAscope), and raised serum growth hormone. The route-of-administration angle is the notable contribution: it suggests intranasal GHRP-6 can engage central ghrelin signaling in mice where intranasal ghrelin and MK-0677 did not. Caveats: single species, mechanistic endpoints (feeding, neuronal activation, GH), and no efficacy or safety claims for humans. These are preclinical findings; human data would be needed before clinical conclusions.
Plain-language abstract
This mouse study asked whether ghrelin-like compounds can reach the brain when delivered through the nose. Researchers compared intranasal ghrelin, GHRP-6, and another ghrelin mimetic (MK-0677). Only GHRP-6 increased eating, and it did so without obvious side effects, by prompting mice to eat more often and in larger amounts. Brain analysis showed GHRP-6 switched on appetite-controlling neurons in a region called the arcuate nucleus, and it also raised blood levels of growth hormone. The other two compounds did not produce these effects by the nasal route. The takeaway is that intranasal GHRP-6 was able to engage the brain's ghrelin system in mice, which is interesting for how such peptides might be delivered. This is an early animal study, and it does not show what intranasal GHRP-6 does in humans.