ISSN:
1432-1106
Keywords:
Adenylate cyclase
;
Caudate-putamen
;
Dopamine
;
Somatostatin
;
6-hydroxydopamine
;
Kainic acid
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The effect of somatostatin-14 (SRIF) on dopamine-sensitive adenylate cyclase in caudateputamen pellets was studied in naive female rats, and in rats with chemical lesions of the nigrostriatal dopaminergic tract produced by injecion of 6-hydroxydopamine, or of the caudate-putamen itself produced by injection of kainic acid 3 week earlier. In unlesioned rats somatostatin at a concentration of 10−7 moles/1 inhibited adenylate cyclase activation by submaximal concentrations of dopamine, increasing the apparent Km but not altering Emax. In 6-hydroxydopamine lesioned rats somatostatin no longer influenced adenylate cyclase activity, whereas in kainic acid lesioned rats somatostatin still increased the apparent Km for dopamine activation. The effect of somatostatin in untreated and lesioned rats is compatible with a partial competitive antagonism to dopamine. Although the data from the lesioned rats present preliminary results, the dose response characteristics and the effects in lesioned animals suggest a more complex interaction, possibly by binding of somatostatin to an inhibitory subunit of regulatory adenylate cyclase components.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00236035
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