Histochemical patterns in the tadpole tail during normal and thyroxine-induced metamorphosis II. Succinic dehydrogenase, Mg- and Ca-adenosine triphosphatases, thiamine pyrophosphatase, and 5′-nucleotidase

Abstract

The distributions of succinic dehydrogenase (SDH), adenosine triphosphatases (Mg-ATPase, Ca-ATPase), thiamine pyrophosphatase (TPPase), and 5′-nucleotidase (5′-Nase) were demonstrated histochemically in sections of growing and resorbing tails of Rana pipiens tadpoles. The main site of SDH activity was striated muscle, especially under the sarcolemma of small, peripheral cells. Mg-ATPase (pH 7.2) was similarly located but together with TPPase and 5′-Nase, was also present in the epidermis, blood vessel walls, and connective tissue, particularly the myocommata and outer notochordal sheath. TPPase was less active, and 5′-Nase still less active, than Mg-ATPase in the latter two locations. (Mg-ATPase and TPPase were also found in the ependyma of the spinal cord.) On the other hand, Ca-ATPase activity (pH 9.4) was almost uniformly distributed within all striated muscle cells; some activity was also evident in the epidermis and blood vessel walls, as well as in the connective tissue of the fins. In general, as the tail shortened during normal and thyroxine-induced metamorphosis, activity of SDH and of Mg-ATPase in peripheral muscle cells decreased, Ca-ATPase activity in muscle remained more or less the same, and activity of enzymes in other tissues of the tail either remained similar to increased. The present data on the differential distribution of five enzymes related to energy metabolism, transport, and muscle contraction, extend the histochemical catalog of enzyme localizations in the tail of tadpoles throughout early larval and metamorphic stages of development.