Effects of parathyroid hormone and calcitonin on carbonic anhydrase location in osteoclasts of cultured embryonic chick bone

The ultrastructural location of carbonic anhydrase has been examined in osteoclasts of cultured embryonic chick metatarsi. In untreated cultures and in those to which parathyroid hormone (PTH) was added, the enzyme was found in close association with the plasma membrane of the ruffled border. After brief calcitonin treatment (10 min) the ruffled border disappeared and the association of carbonic anhydrase with the plasma membrane was diminished. The results indicate that the hormones employed act directly on embryonic bone to alter osteoclast structure and the intracellular location of carbonic anhydrase.     

Effects of parathyroid hormone and calcitonin on carbonic anhydrase location in osteoclasts of cultured embryonic chick bone

Summary The ultrastructural location of carbonic anhydrase has been examined in osteoclasts of cultured embryonic chick metatarsi. In untreated cultures and in those to which parathyroid hormone (PTH) was added, the enzyme was found in close association with the plasma membrane of the ruffled border. After brief calcitonin treatment (10 min) the ruffled border disappeared and the association of carbonic anhydrase with the plasma membrane was diminished. The results indicate that the hormones employed act directly on embryonic bone to alter osteoclast structure and the intracellular location of carbonic anhydrase.Acknowledgments. This work was supported by NIH grants DE04345 and AM20374. Dr Cao was a visiting scientist from the Department of Biology, East China Normal University, Shanghai, The Peoples Republic of China. We thank Kathryn Majarwitz for assisting with the morphometric analysis. The PTH was provided by the National Institute of Arthritis, Diabetes, Digestive and Kidney Diseases of the National Institutes of Health, US Department of Health and Human Services.     

Effects of intracellular or extracellular application of tetraethylammonium on the action potential in cultured chick embryonic heart muscle cell

Summary The effects of tetraethylammonium (TEA) on the action potential in cultured chick embryonic heart muscle cells were investigated. The onset of prolongation of the action potential occurred within 10 min following intracellular iontophoretic application of TEA, but after more than 50 min following extracellular application. These facts suggest that the major site of action of TEA is on the inner surface of the membrane in these cells.     

Influence of progesterone on protein and RNA synthesis in cultured chick embryo liver cells

Summary Chick embryo liver primary cultures, when added with progesterone, exhibit, in comparison with the controls, a normal growth, a decline of both³H-uridine uptake and incorporation into total RNA, a decline of³H-leucine and¹⁴C serine incorporation into the proteins. Progesterone is not able to stimulate phosvitin synthesis induction.These studies were supported in part by the Italian CNR grants.     

Effects of dibutyryl cyclic AMP on cultured brain cells from chick embryos of different ages

Summary The effect of dibutyryl cyclic AMP on cultivated astroblasts from 8-, 12- and 15-day-old chick embryo brain has been studied. The results show that these cells must have reached some degree of maturation in ovo to become morphologically differentiated by the cyclic nucleotide.     

Influence of progesterone on protein and RNA synthesis in cultured chick embryo liver cells.

Chick embryo liver primary cultures, when added with progesterone, exhibit, in comparison with the controls, a normal growth, a decline of both 3H-uridine uptake and incorporation into total RNA, a decline of 3H-leucine and 14C serine incorporation into the proteins. Progesterone is not able to stimulate phosvitin synthesis induction.     

Histochemical study of dissociated nerve cells from embryonic chick cerebral hemispheres in flask cultures

Zusammenfassung Die Differenzierung von dissoziierten Grosshirnneuronen in Plastikflaschenkulturen wurde mit histochemischen Methoden, Nisslfärbung, Silberimprägnation der Nervenfasern und Acetylcholinesteraseaktivität untersucht.

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with the technical assistance ofM. F. Knoetgen

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Direct toxic effect of isoproterenol on cultured cardiac muscle cells

Summary Isoproterenol at relatively high doses (2.5 mg/ml) has a marked toxic effect on rat heart muscle cells cultivated in vitro. This effect is not prevented by propranolol and therefore is not mediated by beta adrenergic receptors.This work has been supported in part by a grant from the Muscular Dystrophy Association, Inc. to Prof. M. Aloisi.     

Effects of thyrotropin and thiouracil on embryonic chick thyroidin vitro

Zusammenfassung Schilddrüsenanlagen von Hühnerembryonen, in Ambinon-Medium kultiviert, entwickeln sich schneller und zeigen beschleunigte intrafollikuläre Kolloidbildung. Mit Thiourazil behandelte Kulturen liessen retardierte Follikelbildung und Kolloidbildung erkennen.     

Effects of dibutyryl cyclic AMP on cultured brain cells from chick embryos of different ages.

The effect of dibutyryl cyclic AMP on cultivated astroblasts from 8-, 12- and 15-day-old chick embryo brain has been studied. The results show that these cells must have reached some degree of maturation in ovo to become morphologically differentiated by the cyclic nucleotide.     

Morphological effects of serotonin and ketanserin on embryonic chick skin in vitro

Summary Cell and organotypical cultures are used to study the direct effect of serotonin and of ketanserin, a serotonin antagonist, on dermal and epidermal cells of embryonic chick skin. Ketanserin stimulates the increase in cell number and inhibits the differentiation, whereas serotonin stimulates differentiation and inhibits the increase in cell number.     

Morphological effects of serotonin and ketanserin on embryonic chick skin in vitro

Cell and organotypical cultures are used to study the direct effect of serotonin and of ketanserin, a serotonin antagonist, on dermal and epidermal cells of embryonic chick skin. Ketanserin stimulates the increase in cell number and inhibits the differentiation, whereas serotonin stimulates differentiation and inhibits the increase in cell number.