title: Dietary fish protein lowers blood pressure and alters tissue polyunsaturated fatty acid composition in spontaneously hypertensive rats.
abstract: OBJECTIVE
  To investigate the effect of two types of dietary protein on blood pressure, liver fatty acid desaturation and composition, and urine 6-keto-prostaglandin-F (PGF(1alpha)) level, the metabolite of prostacyclin.
  
  
  METHODS
  5-wk-old spontaneously hypertensive rats were fed 20% casein or purified fish protein. The fat source was 5% ISIO oil, which contains 47.9% (omega-6) and 1.7% (omega-3) total polyunsaturated fatty acids. After 2 mo on the diet, systolic blood pressure was reduced with fish protein compared with casein (189.8 +/- 10.5 versus 220.7 +/- 8.7).
  
  
  RESULTS
  Excretion of 6-keto-PGF(1alpha) in urine was negatively correlated with blood pressure. Liver cholesterol and phospholipid concentrations were 1.71- and 1.27-fold lower with fish protein than with casein, respectively. The fish protein diet lowered the 20:4(omega-6) proportion and the ratio of 20:4(omega-6) to 18:2(omega-6) in liver microsomal lipids and phospholipids, which was due to the reduced microsomal Delta6(omega-6) desaturation activity. Dietary protein source did not affect omega-3 fatty acid composition, and this was associated with a similar activation of Delta6(omega-3) desaturation in liver microsomes.
  
  
  CONCLUSIONS
  The present data indicated a significant blood pressure-lowering effect caused by fish protein, rather than by casein, that modified the fatty acid composition of liver phospholipids and liver microsomal total lipids.
authors.affiliation: Laboratoire de Nutrition Clinique et Métabolique, Faculté des Sciences, Université d'Oran, Es Sénia, Algeria.
authors.forename: Dalila
authors.initials: D
authors.lastname: Ait-Yahia
authors.forename: Sihem
authors.initials: S
authors.lastname: Madani
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Savelli
authors.forename: Josiane
authors.initials: J
authors.lastname: Prost
authors.forename: Malika
authors.initials: M
authors.lastname: Bouchenak
authors.forename: Jacques
authors.initials: J
authors.lastname: Belleville
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000652:urine; D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage; D001794:Blood Pressure / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D002364:Caseins / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000378:metabolism*; D004044:Dietary Proteins / Q000008:administration & dosage*; D044943:Fatty Acid Desaturases / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D029941:Fish Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D006973:Hypertension / Q000178:diet therapy; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D008099:Liver / Q000033:anatomy & histology / Q000378:metabolism; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology; D009929:Organ Size / Q000187:drug effects; D011460:Prostaglandins F / Q000652:urine; D051381:Rats; D011918:Rats, Inbred SHR
chemical_list: D000959:Antihypertensive Agents; D002364:Caseins; D004042:Dietary Fats, Unsaturated; D004044:Dietary Proteins; D005231:Fatty Acids, Unsaturated; D029941:Fish Proteins; D008055:Lipids; D011460:Prostaglandins F; D015121:6-Ketoprostaglandin F1 alpha; D044943:Fatty Acid Desaturases; C100006:prostaglandin F1