Special capabilities of the sexes: differences in the molecular repertoire of mammal brain, heart and skeletal muscle.
World records for men's and women's (anaerobic) 200 meter dash are 19.67 and 21.9 seconds respectively. Here the transphosphorylation mechanisms are operative and not the glycolytic anaerobic and aerobic ones. The purpose of this paper is to try to find molecular differences during the neuro-muscular sexual differentiation in the Wistar rat. Creatine kinase (CPK: EC 2.7.3.2) as model transphosphorylase and the protein synthesis pattern, determined from the post 125,000 x g cytosol fraction of the brain, heart and masseter muscle, were chosen as molecular monitors. The CPK specific activity profiles showed differences among tissues and sexes. In rats with similar weights between 200 and 320 g, the epigenetic control of protein synthesis in the studied tissues, reflected genome differential activation depending on sex and age. The electrophoretograms differed in regard to the number and position of the protein bands of homologous tissues of different sexes. As an original finding, against the generally accepted criterion (the brain fundamentally synthesizes BB-CPK isoenzyme), MB-CPK and MM-CPK isoenzymes appeared in the brain of both sexes. The molecular sexual differences in the studied tissues determine functional and anatomical differences.
D000818:Animals; D001835:Body Weight; D001921:Brain / Q000201:enzymology; D002625:Chemistry, Organic; D003402:Creatine Kinase / Q000032:analysis*; D003600:Cytosol / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D008406:Masseter Muscle / Q000201:enzymology; D008660:Metabolism; D009206:Myocardium / Q000201:enzymology; D055601:Organic Chemistry Phenomena; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism; D011301:Preoptic Area / Q000033:anatomy & histology; D051381:Rats; D012727:Sex Characteristics; D012733:Sex Differentiation; D013495:Supraoptic Nucleus / Q000033:anatomy & histology
D007527:Isoenzymes; D010770:Phosphotransferases; D003402:Creatine Kinase