Humoral regulation of heart rate during digestion in pythons (Python molurus and Python regius)

Pythons exhibit a doubling of heart rate when metabolism increases several times during digestion. Pythons, therefore, represent a promising model organism to study autonomic cardiovascular regulation during the postprandial state, and previous studies show that the postprandial tachycardia is gover...

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Vydané v:American journal of physiology. Regulatory, integrative and comparative physiology Ročník 302; číslo 10; s. R1176
Hlavní autori: Enok, Sanne, Simonsen, Lasse Stærdal, Pedersen, Signe Vesterskov, Wang, Tobias, Skovgaard, Nini
Médium: Journal Article
Jazyk:English
Vydavateľské údaje: United States 15.05.2012
Predmet:
Animals
Blood Pressure - drug effects
Blood Pressure - physiology
Boidae - physiology
Cromolyn Sodium - pharmacology
Digestion - physiology
Gastrins - antagonists & inhibitors
Gastrins - drug effects
Heart Rate - physiology
Histamine - metabolism
Histamine Antagonists - pharmacology
Mast Cells - drug effects
Mast Cells - metabolism
Models, Animal
Postprandial Period - physiology
Proglumide - pharmacology
Receptors, Cholecystokinin - antagonists & inhibitors
Receptors, Cholecystokinin - drug effects
Tachycardia - physiopathology
ISSN:1522-1490, 1522-1490
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Shrnutí:Pythons exhibit a doubling of heart rate when metabolism increases several times during digestion. Pythons, therefore, represent a promising model organism to study autonomic cardiovascular regulation during the postprandial state, and previous studies show that the postprandial tachycardia is governed by a release of vagal tone as well as a pronounced stimulation from nonadrenergic, noncholinergic (NANC) factors. Here we show that infusion of plasma from digesting donor pythons elicit a marked tachycardia in fasting snakes, demonstrating that the NANC factor resides in the blood. Injections of the gastrin and cholecystokinin receptor antagonist proglumide had no effect on double-blocked heart rate or blood pressure. Histamine has been recognized as a NANC factor in the early postprandial period in pythons, but the mechanism of its release has not been identified. Mast cells represent the largest repository of histamine in vertebrates, and it has been speculated that mast cells release histamine during digestion. Treatment with the mast cell stabilizer cromolyn significantly reduced postprandial heart rate in pythons compared with an untreated group but did not affect double-blocked heart rate. While this study indicates that histamine induces postprandial tachycardia in pythons, its release during digestion is not stimulated by gastrin or cholecystokinin nor is its release from mast cells a stimulant of postprandial tachycardia.
Bibliografia:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:1522-1490
1522-1490
DOI:10.1152/ajpregu.00661.2011