Food intake abolishes the response of rat jejunal Na+,K+-ATPase to dopamine

• Type: Article in International Scientific Journal
• Date: 2000

Authors

lucas-teixeira, v (Author) Other; vieira-coelho, ma (Author) Other; soares-da-silva, p (Author) FMUP

Journal

Title: Journal of Nutrition

Vol. 130

Pages: 877-881

ISSN: 0022-3166

Publisher: American Society for Nutritional Sciences

Indexing

ISI Web of Knowledge - 12 Citations

Scopus - 13 Citations

Scientific classification

FOS: Medical and Health sciences > Health sciences

Other information

Authenticus ID: P-001-0F5

Abstract (EN): The aim of the present study was to evaluate whether the sensitivity of jejunal Na+,K+-ATPase to inhibition by dopamine (DA) in young rats is related to the type of food (breast milk vs. solid) or reflects a developmental adaptation. When 18-d-old rats were separated from their dams and fed solid food (the same used to feed adult rats) for 2 d, intestinal Na+,K+-ATPase activity was significantly greater than that of breast-fed pups of the same age (20 d) (127 +/- 8 vs. 52 +/- 4 nmol Pi . mg protein(-1) . min(-1); P < 0.05). Activity in rats fed solid food was insensitive to inhibition by 1 mu mol/L DA. Na+ ,K+-ATPase activity in 60-d-old rats (117.4 +/- 4.2 nmol Pi . mg protein(-1) . min(-1)) was also higher (P < 0.05) than in breast-fed rats, and DA (1 mu mol/L) did not inhibit enzyme activity. The B-max value for binding of [H-3]-Sch 23390 in 20-d-old breast-fed rats did not differ from that in age-matched rats fed a solid food for 2 d and or that in 60-d-old rats. Levels of DA, but not L-3,4-dihydroxyphenylalanine and amine metabolites, in the jejunal mucosa of 20-d-old rats that had eaten solid food for 2 d were 60% lower than in age-matched rats, breast-fed rats, and not different from those in the jejunal mucosa of 60-d-old rats fed the solid food. We conclude that in adult rats, in contrast to in young rats, DA does not inhibit jejunal Na+,K+-ATPase activity, and food intake in young rats plays an important role in the development of the insensitivity of Na+,K+-ATPase activity to DA.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5