Control of rectal gland secretion by blood acid–base status in the intact dogfish shark (Squalus acanthias)

2007 ◽  
Vol 156 (2) ◽  
pp. 220-228 ◽  
Author(s):  
Chris M. Wood ◽  
R. Stephen Munger ◽  
Jill Thompson ◽  
Trevor J. Shuttleworth
Keyword(s):  
Squalus Acanthias ◽  
Gland Secretion ◽  
Rectal Gland ◽  
Acid Base ◽  
Acid Base Status ◽  
Dogfish Shark

Characterization of the endogenous intestinal peptide that stimulates the rectal gland of Scyliorhinus canicula

1995 ◽  
Vol 268 (6) ◽  
pp. R1359-R1364 ◽  
Author(s):  
W. G. Anderson ◽  
J. M. Conlon ◽  
N. Hazon
Keyword(s):  
High Performance ◽  
Squalus Acanthias ◽  
Gland Secretion ◽  
Rectal Gland ◽  
Maximal Response ◽  
Dependent Manner ◽  
Gut Peptides ◽  
Scyliorhinus Canicula ◽  
Dose Dependent

It has been postulated that gut peptides play a major role in the regulation of rectal gland secretion in elasmobranchs. An isolated perfused rectal gland secretion in elasmobranchs. An isolated perfused rectal gland preparation was developed for Scyliorhinus canicula that responded to dibutyryl 3',5'-cyclic monophosphate plus 3-isobutyl-1-methylxanthine, increasing chloride clearance rates threefold over basal levels. Activity was stimulated by an endogenous peptide, isolated in pur form by reverse-phase high-performance liquid chromatography from the intestine of S. canicula. The primary structure was established as Ser-Pro-Ser-Asn-Ser-Lys-Cys-Pro-Asp-Gly-Pro-Asp-Cys-Phe-Val-Gly-Leu-Met- NH2. This is a sequence identical to that of the tachykinin scyliorhinin II. Perfusion of synthetic scyliorhinin II increased secretion rate in the rectal gland of S. canicula in a dose-dependent manner with a maximal response at 10(-6) M, whereas vasoactive intestinal peptide, a stimulator in the spiny dogfish, Squalus acanthias, had no effect. We propose that scyliorhinin II is the uncharacterized peptide rectin, previously identified from the intestine of S. canicula.

scholarly journals The acid-base status of prenatal pups of the dogfish, Squalus acanthias, in the uterine environment

1986 ◽  
Vol 125 (1) ◽  
pp. 173-179 ◽  
Author(s):  
G. A. Kormanik ◽  
D. H. Evans
Keyword(s):  
Plasma Lipid ◽  
Ammonia Concentration ◽  
Squalus Acanthias ◽  
Acid Base Balance ◽  
Acid Base ◽  
Co2 Partial Pressure ◽  
Uterine Fluid ◽  
Base Balance ◽  
Acid Base Status ◽  
Uterine Environment

The acid-base status of late-term Squalus acanthias L. pups in the uterine seawater environment was examined. Blood values for pH, total CO2, partial pressure of CO2, urea and sodium concentrations in late-term pups were not significantly different from those of the mothers. Haematocrit was slightly lower, while total plasma lipid and ammonia concentrations were several times higher. The uterine environment in which these pups reside and maintain normal acid-base status is nevertheless quite remarkable. In the later months of gestation, up to six pups (approx. 60 g each) reside in each horn of the uterus, in about 100 ml of seawater, in which they ventilate. While the major ion concentrations of the uterine fluid resemble normal seawater, the pH may be as low as 5.9, and the ammonia concentration as high as 22 mmol l-1. This system provides a unique opportunity to study acid-base balance, respiration and nitrogenous waste excretion in developing elasmobranchs under quite unusual conditions.

Pardaxin increases solute permeability of gills and rectal gland in the dogfish shark (Squalus acanthias)

1984 ◽  
Vol 78 (2) ◽  
pp. 483-490 ◽  
Author(s):  
Naftali Primor ◽  
Jose A. Zadunaisky ◽  
H.Victor Murdaugh ◽  
James L. Boyer ◽  
John N. Forrest
Keyword(s):  
Squalus Acanthias ◽  
Rectal Gland ◽  
Solute Permeability ◽  
Dogfish Shark

scholarly journals Control of rectal gland secretion in the dogfish (Squalus acanthias): steps in the sequence of activation

1986 ◽  
Vol 122 (1) ◽  
pp. 99-112
Author(s):  
D. Erlij ◽  
R. Rubio
Keyword(s):  
Blood Pressure ◽  
Cyclic Amp ◽  
Volume Expansion ◽  
High Energy ◽  
Squalus Acanthias ◽  
Gland Secretion ◽  
Rectal Gland ◽  
High Energy Phosphate ◽  
Arterial Blood ◽  
Phosphate Compounds

We measured the venous and arterial pressure, as well as the rate of secretion and content of cyclic AMP and high energy phosphate compounds, of the rectal gland of the anaesthetized dogfish, Squalus acanthias (L.). Intravenous infusion of isotonic solutions produced a very large increase in the rate of secretion by the rectal gland. The increase in secretion was preceded by an increase in venous blood pressure, but arterial blood pressure was not modified. Injections of small doses of veratridine stimulated gland secretion when given in the vicinity of the heart but not when given in the dorsal aorta. During volume expansion the creatine phosphate and ATP content of the gland were markedly reduced, while ADP and AMP as well as cyclic AMP content were increased. We conclude that: volume expansion leads to the release of a message that activates adenyl cyclase in the gland; the increased venous pressure may be the initial signal in the sequence that leads to the release of the activating messenger; there is a receptor mechanism in the atrial and cardiac region that triggers the sequence that activates glandular secretion; the reduction in the content of high energy phosphate compounds during volume expansion is caused by an increase in energy expenditure, probably due to gland secretion.

Hormonal regulation of active chloride transport in the dogfish rectal gland

1979 ◽  
Vol 237 (2) ◽  
pp. F138-F144 ◽  
Author(s):  
J. S. Stoff ◽  
R. Rosa ◽  
R. Hallac ◽  
P. Silva ◽  
F. H. Epstein
Keyword(s):  
Cyclic Amp ◽  
Vasoactive Intestinal Peptide ◽  
Active Transport ◽  
Hormonal Regulation ◽  
Chloride Transport ◽  
Squalus Acanthias ◽  
Rectal Gland ◽  
Electrolyte Homeostasis ◽  
Dogfish Shark

Active transport of chloride is modulated by cyclic AMP in the rectal gland of Squalus acanthias. Vasoactive intestinal peptide (VIP) specifically activates the production of cyclic AMP by the gland and stimulates the secretion of chloride. Somatostatin inhibits VIP-induced secretion but has no effect alone. Both these peptides are present in the dogfish shark and may play an important role in electrolyte homeostasis.

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