Relationships between blood flow and secretion in the isolated perfused canine pancreas

Abstract

SUMMARY1. Stimulation by a continuous intra-arterial infusion of secretin caused a marked vasodilatation in the pancreato-duodenal preparation or in the isolated pancreas perfused with whole heparinized blood. There was no difference in the vasomotor effects of two unequally purified preparations of secretin. The fact that the vasodilatation was still observed when the duodenum was removed proved that the haemodynamic effect of secretin was initiated in the pancreas itself.2. The secretary response of the pancreas to a given dose of secretin was larger when the blood pressure was kept constant by increasing the blood flow than when the blood pressure was allowed to fall by maintaining the blood flow at a fixed value. It is concluded that the vasodilatation plays a role in the functional regulation of the pancreatic response to secretin. 3. The correlation between blood flow and arterial pressure on the one hand, and the secretary response to secretin on the other, was not mediated by the control of respiration since there was no variation in oxygen uptake in response to a variation in the blood flow. This correlation was still observed when the venous blood was discarded and therefore could not be explained by variations in the rate of recirculation of secretin. It was observed too in experiments where the duodenum was removed, the pancreas alone being introduced into the perfusion apparatus, which indicated that this effect was not mediated by a control of the release of secretin by the duodenum.

Indirect evidence for short-loop negative feedback of insulin secretion in the rat

“…Relationships between perfusion flow rate and hor¬ mone release, which are thought to be correlated with changes in hormone autofeedback, have been reported from a variety of isolated perfused organs, such as the rat heart (Fuder, Barth, Wiebelt & Muscholl, 1984), the rat adrenal (Hinson, Vinson, Whitehouse & Price, 1986;) and the human pituitary gland (Boscaro, Sonino, Paoletta et al 1988). Using the isolated perfused pancreas, relationships between flow rate and exocrine secretory function have been observed (Augier, Boucard, Pascal et al 1972). With respect to endocrine secretion, Grodsky et al (1968) did not observe any effect of a rapid decrease in perfusion flow rate on total insulin secretion.…”

Influence of Gastrointestinal Hormones on Tumor Microcirculation of Experimental Pancreatic Cancer in the Rat

“…Cholecystokinin, bombesin, epidermal growth factor, and secretin stimulate the cell proliferation, while somatostatin exerts an inhibitory effect [2, 18]by direct interaction with its receptors [19, 20, 21]. It is well known that gastrointestinal hormones also influence the pancreatic microcirculation [22]. A direct relationship between organ perfusion and physiological stimulation has been demonstrated [4, 5].…”

<i>In-sit</i><i>u</i>-Isolated Perfused Rat Pancreas: a New Method for Pharmacological Studies of the Exocrine Pancreas

“…Practically, the isolated perfused organ provides a good compromise between this ideal need and technical frontiers: anatomy is preserved including pancreatic parenchyma, blood vessels and excre tory ducts. The method also allows for total recovery of the secreted juice without contamination.The method has already been used in dogs (1,13,14,18), cats (3) and rats (15,19,23); the above techniques require an accurate operating procedure, a sophisticated apparatus, and, in some cases, the use of expensive animals. Con- versely, in rats, a method o f m-s/fw-isolated perfused pancreas could allow a faster set-up, the use of cheaper animals, and, possibly, experiments in series.…”