EFFECT OF ALPHA-HUMAN ATRIAL-NATRIURETIC-PEPTIDE ON THE SYNTHESIS OF DOPAMINE IN THE RAT-KIDNEY

• Type: Article in International Scientific Journal
• Date: 1992

Authors

soares-da-silva, p (Author) FMUP; Fernandes MH (Author) FMDUP

Journal

Title: British Journal of Pharmacology

Vol. 105

Pages: 869-874

ISSN: 0007-1188

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 20 Citations

Scopus - 20 Citations

Other information

Authenticus ID: P-001-PP7

DOI: 10.1111/j.1476-5381.1992.tb09070.x

Abstract (EN): 1 The present study has examined the influence of alpha-human atrial natriuretic peptide (alpha-hANP) on the synthesis of dopamine and its deamination into 3,4-dihydroxyphenylacetic acid (DOPAC) in rat kidney slices loaded with exogenous L-dihydroxyphenylalanine (L-DOPA). 2 Alpha-hANP (3.3 and 330 nM) was found to produce a marked reduction (63- 78% reduction) in the time-dependent accumulation of newly-formed dopamine and of its deaminated metabolite DOPAC in kidney slices loaded with 10-mu-M L-DOPA. Alpha-hANP (330 nM) was also found to decrease the accumulation of newly-formed dopamine (45- 66% reduction) and DOPAC (38- 61% reduction) in experiments in which increasing concentrations (1- 100-mu-M) of L-DOPA were used. This inhibitory effect was found to be potentiated by zaprinast (M&B 22,948; 10-mu-M), a guanosine cyclic 3',5'-monophosphate (cyclic GMP) phosphodiesterase inhibitor. Alone, zaprinast also decreased the accumulation of both dopamine (54- 71% reduction) and DOPAC (73- 92% reduction). 3 In kidney homogenates, alpha-hANP (330 nM) was found to affect neither the formation of dopamine nor its deamination to DOPAC. 4 Both alpha-hANP (330 nM) and zaprinast (10-mu-M) were found not to affect the formation of dopamine and DOPAC in kidney slices obtained from rats on a high salt diet during the previous 6 weeks. A similar situation was also found to occur when kidney slices obtained from 24-months old rats were used. 5 The results obtained suggest that the inhibitory effect of alpha-hANP on the renal synthesis of dopamine is dependent on the activation of a membrane-operated mechanism, coupled to the enzyme guanylate cyclase, controlling the entry of L-DOPA into the cells.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6