Effect of Skeletal Muscle Homogenates on the Differentiation of the Chick ChorioAllantoic Membrane

Abstract

THE hyperplastic and metaplastic effects of muscle homogenates and muscle extracts on the chorio-allantoic membrane of the chick have recently been the objects of a number of investigations^1–4. Van Haefton contends that cell-free muscle homogenates pipetted on to the chorio-allantoic membrane can induce the development of non-striated ‘myocytes’ within the mesoderm of the membrane³. Ebert¹ has also reported the induction of occasionally striated ‘muscle’ cells following the introduction of ribonucleic acid extracted simultaneously from chicken cardiac muscle and Rous sarcoma virus. Ebert recognizes the possibility that van Haefton has observed the proliferation of cells remaining in the ‘cell-free’ homo-genate rather than a response of the membrane itself⁵. Wilt and Stolz⁴ have recently repeated the experiments of van Haefton with similar results. They conclude that the non-striated, oriented, elongated cells found within the chorio-allantoic membrane mesenchyme are of host rather than graft origin, thereby representing a genuine response of the chorio-allantoic membrane to components of the muscle homogenate. They further conclude that present evidence does not justify statements regarding the nature of the response.