A histochemical study of the developing tibiotarsus in Malathion-treated chick embryos

1972 ◽  
Vol 50 (10) ◽  
pp. 1293-1298 ◽  
Author(s):  
M. Ho ◽  
M. A. Gibson
Keyword(s):  
Alkaline Phosphatase ◽  
Ribonucleic Acid ◽  
Acid Content ◽  
Histochemical Study ◽  
Glycogen Storage ◽  
Cartilage Matrix ◽  
Chick Embryos

Chick embryos were exposed to a teratogenic dose of Malathion at 5 days of incubation. The treated tibiotarsi developed micromelia, an asymmetrical deposition of bone spicules, and sites of reduced matrix within the cartilage model. The major histochemical differences occurred in the areas of reduced cartilage matrix. These included a reduction in sulfated mucopolysaccharide and ribonucleic acid content and an increased glycogen storage. Calcification was more extensive in the treated tissues and premature centers of mineralization appeared within the epiphyses. Alkaline phosphatase was associated with sites of ossification and calcification and was, therefore, more extensively distributed in the treated tissues.

The Distribution of Alkaline Phosphatase in Relation to Calcification in Scyliorhinus canicula

1949 ◽  
Vol s3-90 (12) ◽  
pp. 381-390
Author(s):  
I. JOAN LORCH
Keyword(s):  
Alkaline Phosphatase ◽  
Histochemical Study ◽  
Cartilage Matrix ◽  
Calcium Salts ◽  
Scyliorhinus Canicula

1. A histochemical study has been made of alkaline phosphatase in the endoskeleton of dogfish embryos of 18-115 mm. 2. The distribution of phosphatase is compared with that of insoluble calcium salts. 3. Phosphatase was first noted in the chondrocytes and perichondrium at 47 mm. and in the cartilage matrix at 58 mm. 4. Calcification occurred first in the neural plates at 58 mm. and in the skull at 74 mm. No calcification was observed in zones devoid of extracellular phosphatase. 5. As the intensity of calcification increased the amount of phosphatase tended to drop. 6. It is concluded that in elasmobranchs, as in higher animals, extracellular phosphatase is an essential precursor of calcification.

Some histochemical changes underlying shoot initiation in tobacco callus cultures

1970 ◽  
Vol 48 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Trevor A. Thorpe ◽  
Toshio Murashige
Keyword(s):  
Nucleic Acids ◽  
Ribonucleic Acid ◽  
Acid Content ◽  
Deoxyribonucleic Acid ◽  
Histochemical Study ◽  
Callus Cultures ◽  
Tobacco Callus ◽  
Apparent Change ◽  
Shoot Initiation ◽  
Histochemical Changes

A comparative histochemical study of changes in nucleic acids, proteins, and carbohydrates was performed on freeze-substituted samples of tobacco callus, cultured under shoot-forming and non-organ-forming conditions. The DNA (deoxyribonucleic acid) content per cell showed no apparent change, whereas denser staining for RNA (ribonucleic acid) and protein were observed in shoot-forming regions just before and during the initiation of organized structures. The most dramatic finding was the heavy accumulation of starch in shoot-forming tissue; this accumulation preceded any organ formation and was mainly in regions which ultimately gave rise to primordia.

Histogenesis of the islets of Langerhans in insulin-treated chick embryos

1972 ◽  
Vol 50 (3) ◽  
pp. 265-277 ◽  
Author(s):  
R. Kalliecharan ◽  
M. A. Gibson
Keyword(s):  
Alkaline Phosphatase ◽  
Islets Of Langerhans ◽  
Insulin Treatment ◽  
Glycogen Storage ◽  
Initial Increase ◽  
Chick Embryos ◽  
Alpha Cells ◽  
Endogenous Insulin ◽  
Increased Activity ◽  
Initial Delay

Chick embryos were exposed to a teratogenic dose of insulin at the 6-day incubation stage and the effect of this treatment on the histogenesis of the islets of Langerhans was studied throughout the incubation period. The exogenous insulin caused an initial delay in the differentiation of the beta islets and in the elaboration of the endogenous insulin. During the final prehatching stages, the endogenous insulin appeared to be elaborated more rapidly than in the control tissues. The insulin treatment caused an increased activity of the alpha cells and an increased production of glucagon. Histochemically, the ribonucleic acid content of both alpha and beta cells was reduced, especially during the early stages of development. Also, there was an initial increase in glycogen storage and alkaline phosphatase activity within the alpha cells. The beta islets in the insulin-treated tissues, except for the initial delay in their development, showed no significant differences in the glycogen and alkaline phosphatase patterns from the control.

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