[Golgi apparatus and T-tubules in cultured myocytes of rat hearts].

The cytochemical-ultrastructural study of rat ventricular cells grown in tissue culture supported the findings of Kasten (1971) on the existence of a special type of Golgi apparatus around the base of the nucleus of the myocardial cell. TPPase and ATPase activity are also found at the subsarcolemmal cisterns and the lateral vesicles of the sarcoplasmic reticulum. Therefore, well developed triads and diads are visible. These structures, however, require the existence of T-tubules in the cultured neonatal myocardial cells. Up to now the presence of T-tubules in early cultures of rat myocytes was still controversy. The demonstration of the T-tubules completes our knowledge of cultured cardiac myocytes and should be taken into consideration in further biochemical and physiological studies with this in vitro model.