Basic FGF reduces stunning via a NOS2-dependent pathway in coronary-perfused mouse hearts

Area of Science:

• Cardiovascular Biology
• Molecular Medicine
• Biochemistry

Background:

• Ischemia-reperfusion injury (stunning) is a major cause of heart damage.
• Basic fibroblast growth factor (FGF-2) is investigated for its cardioprotective potential.
• Nitric oxide (NO) production is a proposed mechanism for FGF-2's protective effects.

Purpose of the Study:

• To investigate whether FGF-2 protects the heart from ischemia-reperfusion injury by stimulating NO production.
• To elucidate the role of inducible NO synthase (NOS2) in FGF-2-mediated cardioprotection.

Main Methods:

• Coronary-perfused mouse hearts were pretreated with FGF-2 or vehicle.
• Intracellular calcium (Ca(i)(2+)) and NO release were measured.
• Pharmacological inhibition of NOS2 and use of NOS2-deficient (NOS2-/-) hearts were employed.

Main Results:

• FGF-2 pretreated hearts showed improved left ventricular (LV) function and delayed ischemic contracture.
• FGF-2 significantly increased NO release in wild-type hearts but not in NOS2-/- hearts.
• Inhibition of NOS2 or deficiency in NOS2 abolished the protective effects of FGF-2.

Conclusions:

• Basic FGF attenuates myocardial stunning through an NOS2-dependent pathway.
• FGF-2 stimulates NO production via NOS2, offering protection independent of intracellular calcium changes.
• This highlights a novel therapeutic pathway for managing myocardial stunning.