Dose‐dependent, and long‐lasting, effects of repeated intravenous injections of calcium on the canine secretin‐stimulated pancreatic juice secretion

Abstract

The effects of repeated intravenous calcium administration on pancreatic juice secretion were investigated in four Thomas fistula dogs. During stimulation by 1.0 U kg-1h-1 GIH secretin, three Ca doses were administered: 2, 4 and 8 mu mol kg-1 min-1 during 1 h, saline being used in control tests; one dose only was tested per day. It was found that Ca administration induced both acute and long-lasting effects. Acute effects were characterized by an increased response to secretin stimulation. Fluid, HCO3(-), protein and Ca outputs increased significantly in a dose-dependent manner, the increase of protein output being the most dramatic. Long-lasting effects, until now unrecognized, were characterized by a progressive increase of protein secretion during the first hour of secretin stimulation. This increase kept going during the 3 months of repeated calcium injections. Although protein plugs were observed in the juice, sometimes stopping the flow of juice, no pancreatic lesion was found. A second protocol showed that, after discontinuing calcium injections, the long-lasting effects decreased progressively, but protein hypersecretion was still significant 3.5 months later. The importance of these findings regarding chronic pancreatitis due to hyperparathyroidism is discussed.

Clinical profile and outcome of parathyroid adenoma-associated pancreatitis

“…[22] Hypercalcemia can also lead to pancreatic calculi and protein plug formation by altering pancreatic secretion, resulting in ductal obstruction that leads to subsequent attacks of RAP or CP. [27] Apart from calcium, genetic predisposition may also lead to AP in patients with PHPT. [28]…”

Metabolic pancreatitis: Etiopathogenesis and management

“…[58] The resultant ductal obstruction can lead to subsequent attacks of acute or chronic pancreatitis. [32]…”

Persisting modification of dogs' basal exocrine pancreatic secretion after repeated intravenous calcium injections

“…Three of the eight dogs in the calcium treated group did not complete their evaluation: two of these dogs were used for a histological study [7].…”

“…calcium injection increases protein and calcium pancreatic secretion, partly through cholinergic nerves [5, 131. In the conscious dog i.v. calcium injection increases the response of the pancreas to secretin stimulation, fluid, bicarbonate, protein and calcium in a dose-dependent manner [7]. Following the first calcium injection and during the washing out period following secretin injection [7,131, the formation of a protein plug has been observed in the basal juice.…”

“…These plugs can obstruct the flow of pancreatic juice. A similar phenomenon has been observed in chronic alcoholic dogs [9, 131. On the other hand, a long-lasting effect of repeated calcium injection on pancreatic secretion has been observed [7]. Repeated calcium injections induce an irreversible increase in protein secretion which persists after discontinuing calcium.…”