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Mechanisms And Mitigation Of Skeletal Muscle Fatigue In Single Fibers From Older Adults, Aurora Foster

Masters Theses

Skeletal muscle fatigue is the contraction-induced decline in whole muscle force or power, and can be greater in older versus young adults. Fatigue primarily results from increased metabolism elevating phosphate (P_i) and hydrogen (H⁺), which alters myosin-actin interactions; however, which steps of the myosin-actin cross-bridge cycle are changed and their reversibility are unclear. PURPOSE: This study sought to: 1) Examine the effects of elevated P_i and H⁺ on molecular and cellular function, and 2) Test the ability of deoxyadenosine triphosphate (dATP), an alternative energy to adenosine triphosphate (ATP), to reverse the contractile changes induced …

Molecular Machinery For The ‘Kiss And Run’ Mechanism Of Insulin Secretion, Akshata Ramesh Naik

Wayne State University Dissertations

The insulin secreting porosome is a supramolecular lipo-protein complex that

measures roughly 100 – 120 nm in diameter. Porosomes allow transient fusion of insulin

secretory granules to the cell plasma membrane and mediates partial release of secretory

contents. Post secretion, the secretory granule reseals and re-enters to the cell interior.

This is in contrast to the ‘total fusion’ phenomenon, where secretory vesicles completely

fuse at the cell plasma membrane and release all of the contents to the cell exterior. This

study involved a deeper understanding of the transient or ‘kiss-and-run’ mechanism of

cell secretion that involves the insulin secreting porosome …