RESUMEN
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters the cells after binding to the membrane-bound receptor angiotensin-converting enzyme 2 (ACE2), but this may be prevented through interception by soluble ACE2 (sACE2) or by inhibition of the ACE2 receptor, thus obstructing cell entry and replication. The main objective of this study was to investigate if fish intake affected the concentration of sACE2 in rats. The secondary aim was to evaluate the in vitro ACE2-inhibiting activity of fish proteins. Rats were fed cod muscle as 25 % of dietary protein, and blood was collected after 4 weeks of intervention. Muscle, backbone, skin, head, stomach, stomach content, intestine and swim bladder from haddock, saithe, cod and redfish were hydrolysed with trypsin before ACE2-inhibiting activity was measured in vitro. In vivo data were compared using unpaired Student's t test, and in vitro data were compared using one-way ANOVA followed by the Tukey HSD post hoc test. The mean sACE2 concentration was 47 % higher in rats fed cod when compared with control rats (P 0·034), whereas serum concentrations of angiotensin II and TNF-α were similar between the two experimental groups. Muscle, backbone, skin and head from all four fish species inhibited ACE2 activity in vitro, whereas the remaining fractions had no effect. To conclude, our novel data demonstrate that fish intake increased the sACE2 concentration in rats and that the hydrolysed fish proteins inhibited ACE2 activity in vitro.
Asunto(s)
Enzima Convertidora de Angiotensina 2 , COVID-19 , Proteínas de Peces , SARS-CoV-2 , Animales , Ratas , Enzima Convertidora de Angiotensina 2/inmunología , COVID-19/dietoterapia , COVID-19/inmunología , COVID-19/virología , Peptidil-Dipeptidasa A/metabolismoRESUMEN
PURPOSE: To investigate the effects of diets containing intact or hydrolysed proteins from blue whiting (Micromesistius poutassou) on the development of high blood pressure and markers of kidney function in obese Zucker fa/fa rats which are prone to develop hypertension and renal failure. METHODS: Male rats were fed isocaloric diets containing either intact blue whiting whole meal (BW-WM), blue whiting protein hydrolysate prepared with Alcalase® (BW-HA) or blue whiting protein hydrolysate prepared with Protamex® (BW-HP) as 1/3 of total protein with the remaining 2/3 as casein, or casein as sole protein source (control group). Blood pressure was measured at Day 0 and Day 32. Rats were housed in metabolic cages for 24 h for collection of urine in week 4. After 5 weeks, rats were euthanized and blood was drawn from the heart. The renin and angiotensin-converting enzyme (ACE) inhibition capacities for casein and blue whiting proteins were measured in vitro. RESULTS: The blood pressure increase was lower in rats fed diets containing blue whiting proteins when compared to the control group, whereas markers of kidney function were similar between all groups. The three blue whiting proteins inhibited renin activity in vitro, whereas casein had no effect. The in vitro ACE inhibition was similar for casein, BW-WM and BW-HP proteins, whereas BW-HA protein was less potent. CONCLUSION: Blue whiting protein feeding attenuated the blood pressure increase in obese Zucker fa/fa rats, possibly mediated through the renin-angiotensin system and without affecting markers of kidney function.
Asunto(s)
Proteínas en la Dieta , Proteínas de Peces , Animales , Presión Sanguínea , Riñón , Masculino , Obesidad , Ratas , Ratas ZuckerRESUMEN
Kidney function affects amino acid metabolism and vitamin status. The aims of the present study were to investigate urine and plasma concentrations of amino acids as well as plasma vitamin status in rats with impaired renal function (Zucker fa/fa rats) and in rats with normal kidney function (Long-Evans rats), and to explore the effects of salmon intake on these parameters and potential biomarkers of salmon intake in both rat strains. Male rats were fed diets with casein as sole protein source (control diet) or 25 % protein from baked salmon and 75 % casein for 4 weeks. Urine concentrations of markers of renal function and most amino acids and plasma concentrations of most vitamins were higher, and plasma concentrations of several amino acids including arginine, total glutathione and most tryptophan metabolites were lower in Zucker fa/fa rats compared with Long-Evans rats fed the control diet. Concentrations of kidney function markers were lower after salmon intake only in Zucker fa/fa rats. A trend towards lower urine concentrations of amino acids was seen in both rat strains fed the salmon diet, but this was more pronounced in Long-Evans rats and did not reflect the dietary amino acid content. Urine 1-methylhistidine, 3-methylhistidine, trimethylamineoxide and creatine concentrations, and plasma 1-methylhistidine and creatine concentrations were higher after salmon intake in both rat strains. To conclude, concentrations of amino acids in urine and plasma as well as vitamin status were different in Zucker fa/fa and Long-Evans rats, and the effects of salmon intake differed by rat strain for some of these parameters.
Asunto(s)
Dieta , Enfermedades Renales/sangre , Plasma/metabolismo , Salmón , Vitaminas/sangre , Vitaminas/orina , Aminoácidos/sangre , Aminoácidos/orina , Animales , Biomarcadores/sangre , Peso Corporal , Caseínas/metabolismo , Proteínas en la Dieta/administración & dosificación , Proteínas de Peces/administración & dosificación , Riñón/metabolismo , Pruebas de Función Renal , Masculino , Obesidad/metabolismo , Ratas , Ratas Long-Evans , Ratas Zucker , Insuficiencia Renal/sangre , Insuficiencia Renal/orina , Alimentos Marinos , Especificidad de la EspecieRESUMEN
The triacylglycerol lowering effect of fatty fish and fish oils is well recognized, however we recently showed that salmon intake resulted in higher serum triacylglycerol concentration in obese Zucker fa/fa rats. Since effects of salmon fillet have never before been studied in rats, the objective of this study was to compare effects of salmon intake on serum lipids in hyperlipidemic obese rats with normolipidemic lean rats. Zucker fa/fa rats and Long-Evans rats were fed diets with 25% protein from baked salmon fillet and 75% protein from casein, or casein as sole protein source (control group) for four weeks. Serum triacylglycerol concentration was higher, and cholesterol and apolipoproteinB-100 concentrations were lower in Zucker fa/fa rats fed Baked Salmon Diet compared to Zucker fa/fa rats fed Control Diet, with no differences in serum triacylglycerol, cholesterol and apolipoproteinB-100 between Long-Evans rats fed Baked Salmon Diet or Control Diet. Serum triacylglycerol fatty acid composition showed greater similarities to dietary fatty acids in Zucker fa/fa rats than in Long-Evans rats. To conclude, intake of baked salmon fillet resulted in higher serum triacylglycerol concentration and lower serum cholesterol concentration in hyperlipidemic obese Zucker fa/fa rats but did not affect serum lipids in normolipidemic lean Long-Evans rats.
Asunto(s)
Dieta , Proteínas en la Dieta/farmacología , Conducta Alimentaria , Hiperlipidemias/sangre , Obesidad/sangre , Salmón , Triglicéridos/sangre , Animales , Apolipoproteínas B/sangre , Colesterol/sangre , Culinaria , Proteínas de Peces/farmacología , Masculino , Ratas Endogámicas LEC , Ratas Zucker , Valores de Referencia , Alimentos MarinosRESUMEN
Proteins from different fish species and different raw materials such as fish fillets and by-products have shown promising cardioprotective effects in rodents and humans, including effects on cholesterol metabolism. Blue whiting is used mainly to produce fish meal for the feed industry and during this production, a water-soluble protein fraction, containing small peptides that are easily absorbed and may hold bioactive properties, is isolated. The effects of water-soluble fish protein on cholesterol metabolism were investigated in twelve male obese Zucker fa/fa rats. Rats were fed diets with water-soluble protein from blue whiting (BWW) as 1/3 of the total protein and the remaining 2/3 as casein (BWW group) or with casein as the sole protein source (control group). After 5 weeks intervention, the BWW group had lower serum total, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol concentrations and lower cholesteryl ester concentration compared to controls. Hepatic concentrations of cholesterol, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, and LDL receptors were also lower in the BWW group. The groups had a similar concentration of serum total bile acids and similar fecal excretions of cholesterol and bile acids. To conclude, the BWW diet led to lower concentrations of serum and liver cholesterol in obese Zucker fa/fa rats, probably due to lower hepatic cholesterol synthesis.