Spatial distribution of "tissue-specific" antigens in the developing human heart and skeletal muscle. I. An immunohistochemical analysis of creatine kinase isoenzyme expression patterns.
Using monoclonal antibodies against the M and B subunit isoforms of creatine kinase (CK) we have investigated their distribution in developing human skeletal and cardiac muscle immunohistochemically. It is demonstrated that in skeletal muscle, a switch from CK-B to CK-M takes place around the week 8 of development, whereas in the developing heart, CK-M is the predominant isoform from the earliest stage examined onward (i.e., 4 1/2 weeks of development). In all hearts examined, local differences in concentration of the CK isoforms are observed. The CK-M expression in the developing outflow tract (OFT) and conduction system is described in detail. Between the weeks 5 and 7 of development, the distal portion of the OFT is characterized by low CK-M expression, whereas around the week 8-10 of development the myocardium around the developing semilunar valves in the OFT expresses a very high level of CK-M. At all stages examined, a relatively low CK-M level is observed in those regions in which the "slow" components of the conduction system do develop (e.g., the sinoatrial junction and atrioventricular junction), whereas a relatively high concentration of CK-M is observed in those areas that are destined to become the "fast" components, i.e., the subendocardial myocardium of the ventricles. The high expression of CK-M in the developing "fast components" of the conduction system contrasts with the relatively low expression of CK-M in the force-producing myocardium of the interventricular septum and free ventricular wall.
Wessels
A
A
Department of Anatomy and Embryology, University of Amsterdam, The Netherlands.
Vermeulen
J L
JL
Virágh
S
S
Kálmán
F
F
Morris
G E
GE
Man
N T
NT
Lamers
W H
WH
Moorman
A F
AF
D003402:Creatine Kinase / Q000378:metabolism*; D005333:Fetus / Q000378:metabolism*; D005865:Gestational Age; D006321:Heart / Q000196:embryology*; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes; D009132:Muscles / Q000196:embryology / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D014018:Tissue Distribution
D007527:Isoenzymes; D003402:Creatine Kinase