Pharmacology of octopamine-, dopamine-, and 5-hydroxytryptamine-stimulated cyclic amp accumulation in the corpus cardiacum of the american cockroach,Periplaneta americana L

1987 ◽  
Vol 5 (2) ◽  
pp. 119-128 ◽  
Author(s):  
John W. D. Gole ◽  
Gregory L. Orr ◽  
Roger G. H. Downer
Keyword(s):  
Cyclic Amp ◽  
Periplaneta Americana ◽  
American Cockroach ◽  
Corpus Cardiacum ◽  
Cyclic Amp Accumulation

Corpus cardiacum stimulated trehalose efflux from cockroach (Periplaneta americana) fat body: control by calcium

1985 ◽  
Vol 63 (1) ◽  
pp. 63-66 ◽  
Author(s):  
J. E. Steele ◽  
T. Paul
Keyword(s):  
Cyclic Amp ◽  
Periplaneta Americana ◽  
Saline Solution ◽  
Fat Body ◽  
Surrounding Medium ◽  
Physiological Saline ◽  
Corpus Cardiacum ◽  
Physiological Saline Solution ◽  
Stimulation Of

Cockroach fat body incubated in a simple physiological saline solution releases trehalose to the surrounding medium. The output of trehalose occurs in the absence of ambient Ca2+ and decreases slowly with time. In two separate experiments, 0.1 mM CaCl2 added to the saline increased the output of trehalose on average by 70% but higher concentrations of Ca2+ did not further increase the efflux of trehalose. Stimulation of trehalose efflux by corpus cardiacum extract is absolutely dependent on extracellular Ca2+, no increase occurring beyond the basal level in the absence of the ion. The activity of corpus cardiacum extract increases as the concentration of CaCl2 is increased to 0.5 mM. This concentration of Ca2+ in the saline permits the extract to increase trehalose efflux by as much as 60% above the basal level. Corpus cardiacum extract, as well as the hypertrehalocaemic agents cyclic AMP and theophylline, increase significantly the influx of Ca2+ into fat body in vitro. The basal efflux of trehalose from fat body and that stimulated by corpus cardiacum extract is not dependent on extracellular Mg2+.

Cyclic AMP does not mediate the action of synthetic hypertrehalosemic peptides from the corpus cardiacum of Periplaneta americana

1985 ◽  
Vol 15 (6) ◽  
pp. 703-709 ◽  
Author(s):  
G.L. Orr ◽  
J.W.D. Gole ◽  
A.P. Jahagirdar ◽  
R.G.H. Downer ◽  
J.E. Steele
Keyword(s):  
Cyclic Amp ◽  
Periplaneta Americana ◽  
Corpus Cardiacum

Octopamine-mediated elevation of cyclic AMP in haemocytes of the American cockroach, Periplaneta americana L.

1987 ◽  
Vol 65 (6) ◽  
pp. 1509-1514 ◽  
Author(s):  
J. W. D. Gole ◽  
G. L. Orr ◽  
R. G. H. Downer
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Adult Male ◽  
Periplaneta Americana ◽  
American Cockroach ◽  
Time Dependent ◽  
Blocking Agents ◽  
Adrenergic Blocking ◽  
Camp Levels ◽  
Dose Dependent

The injection of 10 μL of 5 × 10−3 M octopamine into the haemocoel of adult male Periplaneta americana results in a 20 × increase in haemolymph cyclic AMP (cAMP) levels within 3 min. Synephrine also causes a marked increase in haemolymph cAMP, and less pronounced elevations were obtained following the injection of tyramine, dopamine, norepinephrine, 5-hydroxytryptamine, phenylethanolamine, β-phenylethylamine, and L-phenylephrine. The octopamine effect is time dependent for at least 10 min and dose dependent with the EC50 for the injected dose calculated to be about 2.5 × 10−3 M. These results indicate that the octopamine response is receptor mediated and studies on isolated haemocytes suggest that the octopamine-sensitive receptors are located on haemocytes. Incubation of whole haemocytes in medium containing octopamine results in a dose-dependent elevation of cAMP with the EC50 calculated at about 7.5 × 10−6 M. Synephrine, tyramine, and dopamine also elevate cAMP levels in incubated haemocytes, and the activator of adenylate cyclase, forskolin, causes a marked increase in cAMP. The octopamine-mediated response is blocked by mianserin, phentolamine, and cyproheptadine but not by the β-adrenergic blocking agents propranolol and dichloroisoproterenol.

Stable carbon isotope ratios in Periplaneta americana L., the American cockroach

1985 ◽  
Vol 63 (3) ◽  
pp. 584-589 ◽  
Author(s):  
R. F. Miller ◽  
G. L. Orr ◽  
P. Fritz ◽  
R. G. H. Downer ◽  
A. V. Morgan
Keyword(s):  
Periplaneta Americana ◽  
Stable Carbon Isotopes ◽  
Stable Carbon Isotope ◽  
Isotope Ratios ◽  
American Cockroach ◽  
The Other ◽  
Stable Carbon ◽  
Corpus Cardiacum ◽  
Low Carbohydrate Diet ◽  
General Decline

The distribution of stable carbon isotopes in carbohydrate, lipid, and protein of Periplaneta americana was studied in insects raised on two different diets. Cockroaches that received a sucrose supplement in their diet had chitin and lipids enriched in 13C compared with those insects not given sucrose. Sucrose has a high 13C content relative to the other dietary constituents and enrichment was due to the incorporation of sucrose carbon into these body fractions. The isotope ratios of protein and glycogen from insects raised on a low carbohydrate diet differed significantly from those fed sucrose. Respiratory CO2 collected from insects receiving sucrose was more enriched in 13C than that from insects on the other diet, reflecting the source of metabolic fuel. Starved insects showed a general decline in the heavier isotope in respired carbon dioxide, as lipids were used as an energy source. Cockroaches that were injected with corpus cardiacum extract responded by respiring CO2 depleted in 13C, a result similar to those induced by starvation. This result is consistent with experiments demonstrating a switch from carbohydrate to lipid oxidation caused by corpus cardiacum extract.

Amino Acid Composition of Cockroach Hypertrehalosaemic Hormones

1985 ◽  
Vol 40 (1-2) ◽  
pp. 42-46 ◽  
Author(s):  
Gerd Gäde
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
High Performance ◽  
Periplaneta Americana ◽  
Methanesulfonic Acid ◽  
Reversed Phase ◽  
American Cockroach ◽  
Amino Acid Residues ◽  
Corpus Cardiacum ◽  
Acetonitrile Gradient

Hypertrehalosaemic hormones I and II from the corpus cardiacum of the American cockroach (Periplaneta americana) were separated by reversed-phase high-performance liquid chromato­graphy using a Nucleosil C18 column with a trifluoroacetic acid/acetonitrile gradient. The eluent was monitored at 206 nm and the hypertrehalosaemic activity detected by bioassay. The amino acid compositions of hypertrehalosaemic hormone I and II were determined after acid hydrolysis with HCl or methanesulfonic acid. Both neurohormones are octapeptides. Hypertrehalosaemic hormone I contained the amino acids Asp(2), Ser, Glu, Pro, Val, Phe and Trp, whereas hyper­trehalosaemic hormone II contained the amino acid residues Asp, Thr(2), Glu, Pro, Leu, Phe and Trp.

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