How a Hormone Called GIP Affects Blood Flow in Muscles
109-OR: GIP Acutely Blunts Insulin- and GLP-1–Induced Muscle Microvascular Perfusion
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
GIP completely abolished insulin- and GLP-1–induced increases in muscle microvascular perfusion despite no change in hormone levels.
It was expected that insulin and GLP-1 would enhance blood flow, and that GIP might have neutral or supportive effects. Instead, GIP acted as a powerful inhibitor—even in the presence of normal insulin and GLP-1 levels—suggesting it directly overrides their vascular actions.
Practical Takeaways
Be cautious about assuming all incretin hormones improve blood flow—GIP may actually block key vascular benefits of insulin and GLP-1.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
GIP completely abolished insulin- and GLP-1–induced increases in muscle microvascular perfusion despite no change in hormone levels.
It was expected that insulin and GLP-1 would enhance blood flow, and that GIP might have neutral or supportive effects. Instead, GIP acted as a powerful inhibitor—even in the presence of normal insulin and GLP-1 levels—suggesting it directly overrides their vascular actions.
Practical Takeaways
Be cautious about assuming all incretin hormones improve blood flow—GIP may actually block key vascular benefits of insulin and GLP-1.
Publication
Related Content
Claims (5)
When insulin is present, it helps blood vessels in muscles relax, letting more blood flow in. This brings more creatine to the muscle surface, where it can be absorbed.
In male rats, a hormone called GIP can completely stop another hormone, GLP-1, from increasing blood flow to leg muscles—even if the rats eat junk food or regular food—and it does this without changing how much GLP-1 is in the blood.
In rat blood vessel cells, a hormone called GIP makes the vessels tighter by boosting a constricting chemical and blocking a relaxing one — suggesting it can push blood flow in two opposite directions at once.
In male rats, a hormone called GIP can block insulin’s ability to increase blood flow to leg muscles, even when insulin levels stay the same — suggesting GIP directly interferes with how insulin works in the blood vessels of muscle.
In male rats, insulin helps blood flow to leg muscles pretty quickly—but only if they're eating regular food. If they're on a high-fat diet, insulin doesn't do this job well anymore.