Coordinated secretion of alkaline phosphatase into serum and intestine in fat-fed rats.
BACKGROUND
Fat feeding increases the activity of intestinal alkaline phosphatase in the serum. The mechanism underlying this increase is unknown. Surfactant-like particles (SLP) secreted by enterocytes have been implicated in this phenomenon.


OBJECTIVE
To study the effect of feeding fish oil and protein synthesis inhibitors on alkaline phosphatase activity in serum and in different intestinal fractions.


METHODS
Male albino rats were fed 2 mL of fish oil and were injected cycloheximide or actinomycin D. Alkaline phosphatase activity was determined in the serum and intestinal fractions (SLP, mucosa, muscularis).


RESULTS
Feeding fish oil significantly elevated alkaline phosphatase activity in serum (p< 0.001) and intestinal mucosa (p< 0.01). Administration of cycloheximide or actinomycin D significantly reduced alkaline phosphatase activity in serum (p< 0.01) and in intestinal mucosa (p< 0.05). BCIP staining of brush border alkaline phosphatase activity in acrylamide gels yielded similar results.


CONCLUSIONS
These findings suggest a co-ordination between alkaline phosphatase synthesis and its assembly into lipoprotein vesicles, such as SLP, secreted by enterocytes in response to fat feeding.
Grewal
R
R
Department of Biochemistry, Panjab University, Sector 14, Chandigarh-160 014, India.
Mahmood
Akhtar
A
D000469:Alkaline Phosphatase / Q000097:blood / Q000378:metabolism*; D000818:Animals; D004041:Dietary Fats / Q000378:metabolism*; D004195:Disease Models, Animal; D005769:Gastrointestinal Motility / Q000502:physiology; D007413:Intestinal Mucosa / Q000201:enzymology; D007421:Intestine, Small / Q000201:enzymology*; D008297:Male; D008657:Metabolic Clearance Rate; D011336:Probability; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012680:Sensitivity and Specificity
D004041:Dietary Fats; D000469:Alkaline Phosphatase