In:
Acta Endocrinologica, Oxford University Press (OUP), Vol. 89, No. 2 ( 1978-10), p. 404-416
Abstract:
The effects of parathyroid hormone (PTH) and calcitonin (CT) on cAMP metabolism in rat kidney were examined with particular attention to the localization of the hormone-sensitive adenylate cyclase. In the cortical slices, CT produced an accumulation of cAMP only in the absence of PTH or in the presence of PTH in concentrations which did not induce a maximal increase in the cAMP levels. The lack of additive effect of PTH and CT was confirmed by examining the production of [ 14 C]cAMP in the pre-labelled tissue. Although PTH-sensitive adenylate cyclase was demonstrated predominantly in the renal cortex, PTH also stimulated the enzyme of the tip of the renal papilla. The effect was elicited even in the presence of maximally effective concentrations of vasopressin (ADH). CT-sensitive adenylate cyclase was distributed through all the regions of the kidney except for the papillary tip. Its pattern of distribution exhibited a biphasic curve with peaks at inner medulla and outer cortex. The effect of CT on the enzyme from the papillary base was detected only in the absence of ADH. Additivity of the combined stimulation by addition of PTH and CT on adenylate cyclase varied in different regions of the kidney. Additivity was apparently total in papilla, but partial in medulla and absent in cortex. It is concluded that, although the patterns of distribution of adenylate cyclase responsive to PTH, CT and ADH are different, there are interactions of different degrees among the hormones in stimulating renal adenylate cyclase. This is especially true in the renal cortex, where the majority of PTH or CT sensitive adenylate cyclase activity are present. It seems that all the CT-responsive system is partly involved in the system responsive to PTH.
Type of Medium:
Online Resource
ISSN:
0804-4643
,
1479-683X
DOI:
10.1530/acta.0.0890404
Language:
Unknown
Publisher:
Oxford University Press (OUP)
Publication Date:
1978
detail.hit.zdb_id:
1485160-X
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