ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Parathyroid hormone (PTH) greatly increased the level of adenosine 3′,5′ cyclic monophosphate (cAMP) in rabbit costal chondrocytes in culture 2 minutes after its addition. PTH, as well as N6 O2' dibutyryl adenosine 3′,5′ cyclic monophosphate (DBcAMP) and 8 Bromo adenosine 3′,5′ cyclic monophosphate (8 Br-cAMP) induced ornithine decarboxylase (ODC; L-ornithine carboxylyase; EC 4.1.1.17), which reached a maximum 4 hours after their addition. Neither cAMP, N6 O2′ dibutyryl guanosine 3′,5′ cyclic monophosphate (DBcGMP), nor sodium butyrate increased the activity of the enzyme. PTH had no effect on DNA synthesis, while DBcAMP and 8 Br-cAMP decreased DNA synthesis. Expression of the differentiated phenotype of chondrocytes in culture was also induced by PTH, DBcAMP, and 8 Br-cAMP, but not by cAMP, DBcGMP, or sodium butyrate, as judged by morphological change. Glycosaminoglycan synthesis, a characteristic of the cartilage phenotype, began to increase 8 hours after addition of PTH or DBcAMP, reaching a plateau 32 hours after their addition.These findings suggest that PTH induces increase of ODC activity and expression of the differentiated phenotype of chondrocytes through increase of cAMP and that induction of ODC is closely related to expression of the differentiated phenotype of chondrocytes.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1041060212
