Urinary prostaglandin E and kallikrein activity in glomerular hyperfiltration induced by a meat meal in man.
Because renal vasodilator systems may be involved in the physiologic response to a protein meal, we studied the relationship of prostaglandin E (PGE) and kallikrein (KE) activity to the renal hemodynamic changes induced by a meat meal. Ten normal subjects on a maintenance diet providing 1 g protein per kg and 100 mmol Na daily were studied before and after a meal of 86 g of meat protein, once without medication, and again after treatment with indomethacin (150 mg daily for 3 days before and 50 mg the morning of the test). A carbohydrate meal of similar caloric, Na and K content was used in control studies. Glomerular filtration rate (GFR, inulin clearance), renal blood flow (RBF, para-aminohippurate [PAH] clearance), PGE and kallikrein urinary excretion were determined. All studies were performed during water diuresis to avoid bladder catheterization. The protein load induced an increase in GFR (ml/min, mean +/- s.e.m.: baseline 107.2 +/- 6.05, peak postmeal 146.4 +/- 6.79, p less than 0.01) and RBF (baseline 529.7 +/- 42.9, postmeal 678.9 +/- 61.9, p less than 0.05). Renal hemodynamic changes were unrelated to changes in urinary PGE and KE excretion. Indomethacin treatment inhibited PGE excretion by 73% during the test meal but did not modify the protein-induced hyperfiltration. Our results suggest that these renal vasodilator systems are not primarily responsible for the hyperfiltration response. In addition, the data show that inhibition of prostaglandin synthesis is not a practical approach to prevent glomerular hyperfiltration in clinical practice.
Herrera
J
J
Instituto de Investigaciones Biomédicas (INBIOMED), Hospital Universitario de Maracaibo, Venezuela.
Rodríguez-Iturbe
B
B
Parra
G
G
Coello
J
J
García
R
R
Colina-Chourio
J
J
Sinaiko
A
A
D000328:Adult; D004044:Dietary Proteins / Q000008:administration & dosage*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007213:Indomethacin; D007610:Kallikreins / Q000652:urine*; D007678:Kidney Glomerulus / Q000502:physiology*; D008297:Male; D008460:Meat; D011458:Prostaglandins E / Q000652:urine*; D012079:Renal Circulation
D004044:Dietary Proteins; D011458:Prostaglandins E; D007610:Kallikreins; D007213:Indomethacin