Original Paper Rena! Physiol Biochem 1992;15:53-56
Chair of Nephrology/Department of Pediatrics, Institute of Internal Medicine and Metabolic Diseases, Interdepartmental Center for Biological Ultrastructure, Universitá Federico II, Naples, Italy
Key Words Renal hemodynamic response Meat meal Gastrin Bombesin Glucagon
Brain-Gut Peptides and the Renal Hemodynamic Response to an Oral Protein Load: A Study of Gastrin, Bombesin, and Glucagon in Man
Abstract With the aim of disclosing a possibility for gastrin and bombe sin to participate in the postprandial regulation of the renal hemodynamic response, 10 healthy males were studied before and after a meat meal (2 g/kg BW of proteins as cooked red meat). We evaluated the time course changes of glomerular filtration rate (GFR) renal plasma flow (RPF), and the plasma concentrations of gastrin, bombesin, glucagon, and total ami no acids. After the meat meal a significant increase in GFR and RPF was seen, within 30 min, along with an increase in plasma gastrin and glucagon. Bombesin and amino acid con centrations increased at a later time. The data suggest but cannot demonstrate a causal role for gastrin and glucagon in the genesis of the hyperfiltration response to acute protein administration.
Introduction In the course of recent attempts to eluci date the factor(s)/mechanism(s) responsible for renal hemodynamic response to protein/ amino acids [1—3] various hormonal activities
Received: August 29.1990 Accepted: April 22.1991
have been thoroughly scrutinized, amongst them glucagon, insulin, growth hormone, glomerulopressin, prostaglandins, renin, aldo sterone, and atrial natriuretic peptide [4-9]. It is interesting to note that glucagon and insulin are brain-gut peptides, which represent a spe-
Natale Gaspare de Santo Chair o f Nephrology Division o f Pediatric Nephrology Via Pansini 5. Policlinico Cappella Cangiani 1-80131 Naples (Italy)
© 1992 S. Karger AG. Basel 1011-6524/92/ 0151-0053 $2.75/0
Downloaded by: National Univ. of Singapore 137.132.123.69 - 3/15/2020 7:32:49 PM
Natale G. De Santo Giovambattista Capasso Pietro Anastasio Salvatore Coppola Luigi Bellini Attilio Lombardi
dal category of regulatory hormones that are common to the brain and gut. and have a po tential both for kidnev regulation and growth
tions for each clearance period. GFR and CPAh were corrected per 1.73 n r. The filtration fraction was calcu lated as C|„/CPAH.
[ 10.
Analytical Methods Inulin and PAH w'ere measured by colorimetric methods [15. 16], as described elsewhere [5], Plasma concentration of glucagon, gastrin, and bombesin were measured by specific radioimmunoassays [17-19]. Plas ma amino acids were measured by utilizing a Beckman 9119 CL analyzer after deproteinizing with sulfosalicylic acid in L0% lithium citrate. A total of 21 amino acids were detected [5]
Methods Study Population A total of 10 healthy males, aged 20-35 years, par ticipated in the study. They were disease-free as in dicated by medical records/clinical examination, as well as by routine laboratory tests. All were within 10% of the ideal body weight. Their protein intake averaged 1.30 ± 0.30 g/day, their daily Na excretion averaged 114 ± 2 6 mmol. Protein Loading and Renal Function Glomerular filtration rate (GFR) was measured as the inulin clearance (Q„) and renal plasma flow (RPF) as the clearance of p-aminohippurate (CPAn) carried out w ith the constant infusion technique, as described elsewhere [5]. Three clearance studies (C,, Q , and Q ) were per formed. each lasting 30 min. Baseline inulin and CPAH were obtained by averaging Ci, C . and Q values. Sub sequently all subjects underwent a protein load of 2 g/ kg BW in the form of cooked red meat (beefsteak) which was prepared without adding salt or fats, and served without cereals, bread or vegetables, and con sumed within 15-20 min. After beginning the meat meal 5 additional clearances were performed: C.;. C
Chair of Nephrology/Department of Pediatrics, Institute of Internal Medicine and Metabolic Diseases, Interdepartmental Center for Biological Ultrastructure, Universitá Federico II, Naples, Italy
Key Words Renal hemodynamic response Meat meal Gastrin Bombesin Glucagon
Brain-Gut Peptides and the Renal Hemodynamic Response to an Oral Protein Load: A Study of Gastrin, Bombesin, and Glucagon in Man
Abstract With the aim of disclosing a possibility for gastrin and bombe sin to participate in the postprandial regulation of the renal hemodynamic response, 10 healthy males were studied before and after a meat meal (2 g/kg BW of proteins as cooked red meat). We evaluated the time course changes of glomerular filtration rate (GFR) renal plasma flow (RPF), and the plasma concentrations of gastrin, bombesin, glucagon, and total ami no acids. After the meat meal a significant increase in GFR and RPF was seen, within 30 min, along with an increase in plasma gastrin and glucagon. Bombesin and amino acid con centrations increased at a later time. The data suggest but cannot demonstrate a causal role for gastrin and glucagon in the genesis of the hyperfiltration response to acute protein administration.
Introduction In the course of recent attempts to eluci date the factor(s)/mechanism(s) responsible for renal hemodynamic response to protein/ amino acids [1—3] various hormonal activities
Received: August 29.1990 Accepted: April 22.1991
have been thoroughly scrutinized, amongst them glucagon, insulin, growth hormone, glomerulopressin, prostaglandins, renin, aldo sterone, and atrial natriuretic peptide [4-9]. It is interesting to note that glucagon and insulin are brain-gut peptides, which represent a spe-
Natale Gaspare de Santo Chair o f Nephrology Division o f Pediatric Nephrology Via Pansini 5. Policlinico Cappella Cangiani 1-80131 Naples (Italy)
© 1992 S. Karger AG. Basel 1011-6524/92/ 0151-0053 $2.75/0
Downloaded by: National Univ. of Singapore 137.132.123.69 - 3/15/2020 7:32:49 PM
Natale G. De Santo Giovambattista Capasso Pietro Anastasio Salvatore Coppola Luigi Bellini Attilio Lombardi
dal category of regulatory hormones that are common to the brain and gut. and have a po tential both for kidnev regulation and growth
tions for each clearance period. GFR and CPAh were corrected per 1.73 n r. The filtration fraction was calcu lated as C|„/CPAH.
[ 10.
Analytical Methods Inulin and PAH w'ere measured by colorimetric methods [15. 16], as described elsewhere [5], Plasma concentration of glucagon, gastrin, and bombesin were measured by specific radioimmunoassays [17-19]. Plas ma amino acids were measured by utilizing a Beckman 9119 CL analyzer after deproteinizing with sulfosalicylic acid in L0% lithium citrate. A total of 21 amino acids were detected [5]
Methods Study Population A total of 10 healthy males, aged 20-35 years, par ticipated in the study. They were disease-free as in dicated by medical records/clinical examination, as well as by routine laboratory tests. All were within 10% of the ideal body weight. Their protein intake averaged 1.30 ± 0.30 g/day, their daily Na excretion averaged 114 ± 2 6 mmol. Protein Loading and Renal Function Glomerular filtration rate (GFR) was measured as the inulin clearance (Q„) and renal plasma flow (RPF) as the clearance of p-aminohippurate (CPAn) carried out w ith the constant infusion technique, as described elsewhere [5]. Three clearance studies (C,, Q , and Q ) were per formed. each lasting 30 min. Baseline inulin and CPAH were obtained by averaging Ci, C . and Q values. Sub sequently all subjects underwent a protein load of 2 g/ kg BW in the form of cooked red meat (beefsteak) which was prepared without adding salt or fats, and served without cereals, bread or vegetables, and con sumed within 15-20 min. After beginning the meat meal 5 additional clearances were performed: C.;. C
