Intestinal dopaminergic activity in obese and lean zucker rats: Response to high salt intake

• Type: Article in International Scientific Journal
• Date: 2002

Authors

Lucas Teixeira, VA (Author) Other; Hussain, T (Author) Other; Maria Paula Serrão (Author) FMUP; soares-da-silva, p (Author) FMUP; Lokhandwala, MF (Author) Other

Journal

Title: Clinical and Experimental Hypertension

Vol. 24

Pages: 383-396

ISSN: 1064-1963

Publisher: Taylor & Francis

Indexing

ISI Web of Knowledge - 9 Citations

Scopus - 10 Citations

Other information

Authenticus ID: P-000-NS6

DOI: 10.1081/ceh-120004799

Abstract (EN): The present study examined intestinal dopaminergic activity and its response to high salt (HS, 1% NaCl over a period of 24 hours) intake in obese (OZR) and lean Zucker rats (LZR). The basal Na+,K+-ATPase activity (nmol Pi/mg protein/min) in the jejunum of OZR was higher than in LZR on normal salt (NS) (OZR-NS = 111.3 +/- 6.0 vs. LZR-NS = 88.0 +/- 8.3). With the increase in salt intake, the basal Na+,K+-ATPase activity significantly increased in both animals (OZR-HS=145.9 +/- 11.8; LZR-HS=108.8 +/- 6.7). SKF 38393 (10 nM), a specific D-1-like dopamine receptor agonist, inhibited the jejunal Na+,K+-ATPase activity in OZR on HS intake, but failed to inhibit enzyme activity in OZR on NS intake and LZR on NS and HS intakes. The aromatic L-amino acid decarboxylase (AADC) activity in OZR was lower than in LZR on NS intake. The HS intake increased AADC activity in OZR, but not in LZR. During the NS intake the jejunal monoamine oxidase (MAO) activity in OZR was similar to that in LZR. The HS intake significantly decreased MAO activity in both OZR and LZR. The jejunal COMT activity in OZR was higher than in LZR on NS intake. The HS intake reduced COMT activity in OZR but not LZR. It is concluded that inhibition of jejunal Na+,K+-ATPase activity through D, dopamine receptors is dependent on salt intake in OZR, whereas in LZR, the enzyme failed to respond to the activation of D, dopamine receptors irrespective of their salt intake.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 14