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2 Biological Effects
As explained above, pancreastatin is an important mediator in many biological
functions such as autocrine, paracrine or endocrine secretion (see the Fig. 1 ). Thus,
in pancreas and parathyroid the hormonal release is modulated by PST in an auto-
crine manner, whereas in the gastric mucosa occurs a paracrine effect, when ECL
cells release PST modulating gastric secretion (Sanchez-Margalet et al. 1996 ).
Probably, the best described PST effect is the endocrine modulation of insulin
action in the liver, and paracrine/endocrine in the adipocytes (Sanchez-Margalet
et al. 1996 ). In this way, PST results particularly important in physiological studies
of homeostasis of blood glucose and insulin, as well as pathological conditions such
as diabetes mellitus (Sanchez-Margalet et al. 1996 ). For instance, plasma pancreast-
atin concentration was elevated in type 2 diabetes about 3.7 times, being unchanged
in insulin resistance related obesity. Furthermore, this elevation was resistant to
weight loss by diet (O’Connor et al. 2005 ). In the essential hypertension, a symptom
related to metabolic syndrome, plasma levels also appears elevated, and thus PST
could contribute to the insulin resistance that often accompanies this condition
(Sanchez-Margalet et al. 1995 ).
In the next sections we will explore the physiological role of PST as a global
regulator of exocrine and endocrine secretion, as well as energy metabolism or
antagonism of insulin action.
Fig. 1 Target tissues of pancreastatin action
N.E. Evtikhova et al.