Peptidergic modulation of cardiovascular dynamics in the Dungeness crab,Cancer magister |
| |
Authors: | I J McGaw C N Airriess B R McMahon |
| |
Institution: | (1) Department of Biological Science, University of Calgary, T2N 1N4 Calgary, Alberta, Canada;(2) Bamfield Marine Station, V0R 1B0 Bamfield, British Columbia, Canada |
| |
Abstract: | Decapod crustacean pericardial organs contain extensive neurohormonal reserves which can be released directly into the haemolymph
to act as physiological modulators. The present paper concerns the in vivo effects of two pericardial peptides, proctolin
and crustacean cardioactive peptide, on cardiovascular dynamics in the crab Cancer magister. Infusion of proctolin into the pericardial sinus caused a slight decrease in heart rate concurrent with a large increase
in cardiac stroke volume. It decreased haemolymph flow anteriorly through the paired anterolateral arteries and increased
flow posteriorly and ventrally through the posterior aorta and sternal artery, respectively. The threshold for responses occurred
at circulating concentrations of 10-9 mol·l-1, and haemolymph flows remained elevated for up to 30 min after peptide infusion. The effects of crustacean cardioactive peptide
were less dramatic. Heart rate was not affected but a significant increase in stroke volume was observed. Crustacean cardioactive
peptide increased haemolymph flow through the anterolateral arteries and increased scaphognathite rate. The threshold for
crustacean cardioactive peptide activity was higher than for proctolin (10-7 mol·l-1 and 10-6 mol·l-1) but the responses to crustacean cardioactive peptide were of longer duration. The effects of proctolin on regional haemeolymph
distribution in Cancer magister closely resemble the cardiovascular responses of this species when exposed to hypoxic conditions. These peptides may be implicated
as cardiovascular regulators during environmental perturbations. |
| |
Keywords: | Proctolin Crustacean cardioactive peptide Cardiovascular Circulation Crab Cancer magister |
本文献已被 SpringerLink 等数据库收录! |
|