Effect of intravenous infusion of hypertonic glucose solutions on pancreatic HCO3(-) secretion.
To examine why intravenous infusion of hypertonic non-electrolyte solutions inhibit pancreatic HCO3(-) secretion, the relationship between pancreatic HCO3(-) secretion and plasma pH was examined before and following intravenous infusion of hypertonic glucose to 5 anesthetized, secretin infused (2.7 C.U./kg b.wt.h-1) pigs. Hyperglycemia (plasma glucose 103 +/- 6 mmol/l) did not significantly change plasma pH, Na+, K+, Cl- and HCO3(-) concentrations. Hyperglycemia reduced pancreatic water flux by 48 +/- 5% and raised pancreatic juice HCO3(-) concentration by 43 +/- 4 mmol/l. Concurrently, HCO3(-) secretion fell by 34 +/- 5%. Acidosis, produced through intravenous HCl infusion and CO2 addition to inspired air, reduced HCO3(-) secretion by 40 +/- 6 mumol/min and 30 +/- 5 mumol/min per 0.1 pH unit reduction in plasma pH before and during hyperglycemia, respectively, and abolished HCO3(-) secretion at an estimated plasma pH of 6.51 +/- 0.06 before and a pH of 6.63 +/- 0.05 during hyperglycemia. We conclude that hypertonic glucose infusions inhibit pancreatic water flux and cause an increase in pancreatic juice HCO3(-) concentration which may inhibit HCO3(-) secretion through an effect on acid-base balance in secretory cells.
D000136:Acid-Base Equilibrium / Q000187:drug effects; D000818:Animals; D001639:Bicarbonates / Q000032:analysis / Q000378:metabolism*; D001786:Blood Glucose / Q000032:analysis; D005947:Glucose / Q000494:pharmacology*; D005950:Glucose Solution, Hypertonic / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007263:Infusions, Parenteral; D010179:Pancreas / Q000378:metabolism*; D010189:Pancreatic Juice / Q000032:analysis; D013552:Swine; D014882:Water-Electrolyte Balance / Q000187:drug effects
D001639:Bicarbonates; D001786:Blood Glucose; D005950:Glucose Solution, Hypertonic; D005947:Glucose