DEVELOPMENT OF TRANSVERSE TUBULAR SYSTEMS (T-TUBULES) IN THE HAMSTER {MESOCRICETUS AURATUS) MYOCARDIUM.

ABSTRACT

With the aid of an electron microscope the development of

transverse tubules (T-tubules or system) was studied in pre- and

post-natal hamsters (Mesocricetus auratus) labelled with horse

radish peroxidase (HRP). Thin sections (70-90 nm) and semi-thin

sections (800-1000 nm) were cut using an ultramicrotome and

examined under an electron microscope. No evidence of T-tubules

was observed during the pre-natal and first week in neonatal stages

of development when myocytes were characterised by large

cytoplasmic spaces with few and partially developed but

functioning myofibrils. Between seven and fourteen days of postnatal

life, myofibrils developed rapidly and the A-and I-bands

became more distinct. By the seventh day, shallow indentations of

the sarcolemma at the Z-line regions appeared, representing the

early beginnings of the T-system. Wide T-tubule invaginations of

the sarcolemma with cross-sectional diameter of 200-205 nm

began to appear in right and left ventricular myocytes by the

twenty-first day of post-natal life in some Z-line regions of

myofibrils. At this stage also, myofibrils had adopted adult forms,

with well organised cross-striations. Mitochondria were also well

developed, occupying the spaces between rows of myofibrils.

This study supports the view that T-tubules are primarily

adapted for homeostatic functions of the mammalian cardiac

myocytes, improving efficiency of transport of metabolic

substrates and products, and that they are not for excitationcontraction

coupling as presumed by some workers. It also shows

that the wide T-system observed in the studies of myocytes of an

adult hamster is pre-determined, as this feature is noticeable as

early as the third week of post-natal development, coinciding with

maturation of the myofibrils for active adult life.

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APA

ADJENTI, S (2021). DEVELOPMENT OF TRANSVERSE TUBULAR SYSTEMS (T-TUBULES) IN THE HAMSTER {MESOCRICETUS AURATUS) MYOCARDIUM.. Afribary. Retrieved from https://afribary.com/works/development-of-transverse-tubular-systems-t-tubules-in-the-hamster-mesocricetus-auratus-myocardium

MLA 8th

ADJENTI, SAVIOUR "DEVELOPMENT OF TRANSVERSE TUBULAR SYSTEMS (T-TUBULES) IN THE HAMSTER {MESOCRICETUS AURATUS) MYOCARDIUM." Afribary. Afribary, 31 Mar. 2021, https://afribary.com/works/development-of-transverse-tubular-systems-t-tubules-in-the-hamster-mesocricetus-auratus-myocardium. Accessed 25 Jun. 2024.

MLA7

ADJENTI, SAVIOUR . "DEVELOPMENT OF TRANSVERSE TUBULAR SYSTEMS (T-TUBULES) IN THE HAMSTER {MESOCRICETUS AURATUS) MYOCARDIUM.". Afribary, Afribary, 31 Mar. 2021. Web. 25 Jun. 2024. < https://afribary.com/works/development-of-transverse-tubular-systems-t-tubules-in-the-hamster-mesocricetus-auratus-myocardium >.

Chicago

ADJENTI, SAVIOUR . "DEVELOPMENT OF TRANSVERSE TUBULAR SYSTEMS (T-TUBULES) IN THE HAMSTER {MESOCRICETUS AURATUS) MYOCARDIUM." Afribary (2021). Accessed June 25, 2024. https://afribary.com/works/development-of-transverse-tubular-systems-t-tubules-in-the-hamster-mesocricetus-auratus-myocardium