Distribution of serotonergic and dopaminergic nerve fibers in the salivary gland complex of the cockroach Periplaneta americana

Background  

Iron deficiency (ID) results in ventricular hypertrophy, believed to involve sympathetic stimulation. We hypothesized that with ID 1) intravenous norepinephrine would alter heart rate (HR) and contractility, 2) abdominal aorta would be larger and more distensible, and 3) the beta-blocker propanolol would reduce hypertrophy.     

Protease-mediated prophenoloxidase activation in the haemolymph of American cockroach Periplaneta americana

Prophenoloxidase has been successfully obtained from the haemolymph of the cockroach Periplaneta americana using cane sugar saline solution. The proenzyme was activated by various exogenously added proteases such as chymotrypsin, trypsin, subtilisin and thermolysin. Thermolysin was found to be the greatest activator, followed by chymotrypsin and subtilisin. Chymotrypsin activation showed a lag period when compared with the other proteases tested, indicating that activation by chymotrypsin followed an indirect path, whereas, subtilisin and thermolysin activated the proenzyme directly.Exogenously added protease inhibitor showed inhibition towards protease-mediated prophenoloxidase activation. Benzamidine inhibited chymotrypsin and trypsin activation, whereas soybean trypsin inhibitor inhibited trypsin. In situ inhibitor isolated from the haemocytes of Periplaneta americana inhibited the prophenoloxidase activation and showed evidence for the presence of a built-in inhibition system for the release of the components of the prophenoloxidase activating system of P. americana. Electrophoretic localization of activated phenoloxidase showed two bands, suggesting the dimeric condition of high mol. wt prophenoloxidase.     

Changes in blood proteins in the cockroach Periplaneta americana after chemosterilization with metepa

Polyacrylamide gel disc electrophoretic studies on the blood proteins of the adult female cockroach Periplaneta americana made sterile by chemical and by surgical means revealed certain differences. While in surgically sterilized animals only the less mobile protein fractions corresponding to soluble oocyte proteins increased in concentration in the blood, in chemosterilized females certain of the more mobile fractions in addition to those corresponding to the less mobile soluble oocyte proteins showed an increase. Various fractions which registered an initial increase in the chemosterilized females showed a tendency to decrease with time, whereas after surgical sterilization they continued to remain higher. However, ovarian degeneration appeared to be irreversible after chemosterilization. Chemosterilization in the female is accompanied by derangement of protein metabolism and inability of the follicle epithelium to take up even available oocyte proteins from the haemolymph.

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Zusammenfassung Mit Hilfe der Polyakrylamid-Gelscheibe unternommene elektrophoretische Untersuchungen der Blutproteinkörper erwachsener weiblicher Küchenschaben (Periplaneta americana), die durch chemische und chirurgische Mittel sterilisiert worden waren, ergaben gewisse Abweichungen. Während bei chirurgisch sterilisierten Tieren nur die weniger beweglichen Proteinkörperanteile, die den Oozytenproteinen entsprechen, in ihrer Konzentration im Blut anstiegen, zeigten bei chemosterilisierten Weibchen sowohl die beweglicheren als auch die weniger beweglichen Anteile eine Zunahme. Verschiedene Anteile, die bei den chemosterilisierten Weibchen anfänglich mit einem Anstieg reagierten, neigten im Laufe der Zeit dazu, wieder abzunehmen, während sie nach chirurgischer Sterilisation stets höher blieben. Jedoch schien nach Chemosterilisation die Eierstockentartung unwiderruflich zu sein. Als Begleiterscheinungen der Chemosterilisation ergeben sich also Störungen im Proteinmetabolismus und die Unfähigkeit des Follikelepithels, selbst die in der Haemolymphe vorhandenen Oozytenproteinkörper aufzunehmen.

     

The effect of temperature changes on the spontaneous activity in the neural ganglia of the cockroach, Periplaneta americana

1. 1.|The effect of localized heating or protocerebrum (bp), the prothoracic (t₁), metathoracic (t₃) and the sixth abdominal (a₆) ganglion on the spontaneous neuronal firing rate in these ganglia was investigated in Periplaneta americana.

2. 2.|In almost every case heating the ganglion increased the firing rate. The most heat sensitive were bp, t₃ and t₁, a₆ was much less so.

3. 3.|In bp and t₁ the firing rate stayed on an increased level even 90 s after the thermal stimulus was over.

4. 4.|The differentiated thermosensitivity of the tested ganglia is discussed in terms of thermoregulatory behaviour of the cockroach.

Inositol trisphosphate mediates the action of hypertrehalosemic hormone on fat body of the American cockroach, Periplaneta americana

The rate of synthesis of inositol trisphosphate (InsP₃) in trophocytes derived from disaggregated cockroach (Periplaneta americana) fat body increases following treatment of the cells with hypertrehalosemic hormone I or II (HTH-I, -II) in vitro. Trophocytes preloaded with [³H]inositol display a significant increase in InsP₃ synthesis as early as 15 s after addition of the hormone. When the trophocytes are pre-incubated with LiCl and subsequently incubated with HTH the [³H] content of the InsP₃ fraction is greater than that found with HTH alone. This is taken as evidence that inositol monophosphate phosphatase is part of the mechanism for clearing InsP₃ from the cytosol. In contrast to HTH, octopamine, which is also capable of exerting a hypertrehalosemic effect in the cockroach, does not increase the synthesis of InsP₃. 1-Octadecyl-2-methyl-rac-glycero-3-phosphocholine (ET-18-OCH₃), a potent and selective inhibitor of phosphatidylinositol phospholipase C, blocks the activation of phosphorylase by HTH-I as well as the hypertrehalosemic effect induced by the hormone.     

The effect of acclimation temperature and the removal of peripheral temperature receptors on body temperature preference in the cockroach, Periplaneta americana

1. 1.|Body temperature preferences were compared between cockroaches acclimated to different ambient temperatures and between 25°C acclimated cockroaches and cockroaches deprived of their peripheral temperature receptors.

2. 2.|Acclimation to 35°C resulted in a significantly higher mean body temperature and low body temperature selected compared with 25°C acclimated cockroaches.

3. 3.|Cockroaches deprived of their peripheral temperature receptors showed a significantly higher mean high body temperature selected when compared to normal 25°C acclimated cockroaches.

4. 4.|It is concluded that cockroach temperature regulation is more precise than expected and that central temperature receptors are the primary sensing elements for cockroach thermoregulation.

The influence of penetration, distribution, sorption and decomposition on the poisoning of the cockroach Periplaneta americana treated topically with diazoxon

Microchemical techniques were used to assess the rate of penetration of diazoxon into the American cockroach Periplaneta americana L. by measuring loss from the surface of the cuticle after topical application. By similar methods the proportions of the amount entering which were decomposed, absorbed by the tissues, or circulating in the haemolymph were also estimated. About three-quarters of an LD₉₀ of diazoxon (2.6 g) applied to the metathoracic sternum of adult male cockroaches had penetrated the cuticle 2 hr after treatment. The maximum concentration within the cockroach, reached about 1 hour after treatment, was 2.4 M, but two-fifths of this is sorbed on solids, leaving 1.4 M in the total body fluids. The maximum concentration in the haemolymph occurred 1 1/2 hr. after treatment and ranged from 0.9 to 3.4 M, with a median value of 1.8 M. The close relationship between concentration in haemolymph and in total body fluids suggests that they are in approximate equilibrium.An independent estimate of the concentration of diazoxon in the haemolymph of cockroaches treated with an LD₉₀ of the insecticide, made by means of an electrophysiological technique, agreed well with the values obtained from the chemical assay. The maximum concentrations (0.6–1.0 M) was found 1–2 hr. after treatment, when irreversible damage to the nervous system first occurred.The close agreement between the chemical and biological estimates suggests that diazoxon invades the nerve cord from the haemolymph, and that it acts directly, rather than as a metabolite or by the release of a neuroactive material.

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Zusammenfassung Um die Eindringgeschwindigkeit von Diazoxon in die Amerikanische Küchenschabe Periplaneta americana festzustellen, wurden mikrochemische Verfahren benutzt, indem nach örtlicher Aufbringung das Verschwinden von der Oberfläche der Kutikula gemessen wurde. Mit ähnlichen Methoden wurden auch die Anteile der eingedrungenen Menge abgeschätzt, die abgebaut oder von den Geweben absorbiert wurden oder in der Haemolymphe zirkulieren. Das Eindringen von Diazoxon, das auf dem Sternum des Metathorax erwachsener Küchenschaben-Männchen aufgetragen wurde, ist der vergangenen Zeit proportional, und über 3/4 einer LD₉₀ (2,6 g) ist nach 2 Stunden eingedrungen. Die Menge im Insekt wächst eine Stunde nach der Applikation auf etwa 1/5 der angewendeten Dosis und nimmt nach 2 Stunden auf etwa 1/12 ab. Etwa 2/5 der eingedrungenen Menge wird an ungelöste Stoffe gebunden, und in Anbetracht dessen wurde für die maximal erreichte Konzentration in der gesamten Körperflüssigkeit 1,4 M berechnet, was etwa 1/8 der angewandten Dosis entspricht. Die Zeit-Konzentrations-Kurve des Diazoxons in der Haemolymphe einzelner Küchenschaben, die mit einer LD₉₀ behandelt worden waren, hatte einen ähnlichen Verlauf wie die für das gesamte Diazoxon; die Konzentration erreichte ein Maximum 1 1/2 Stunden nach der Behandlung, wobei es von 0,9 bis 3,4 M mit einem Median wert von 1,8 M schwankte. Die enge Beziehung zwischen der Konzentration in der Haemolymphe und in der gesamten Körperflüssigkeit machte es wahrscheinlich, daß sie annähernd im Gleichgewicht miteinander stehen.Bei der Bespülung von Küchenschaben-Ganglien in vitro mit einer Reihe von Diazoxon-Konzentrationen in Kochsalzlösung unter Beobachtung der Vergiftungssymptome in den Metathorax-Ganglien mit elektrophysiologischen Methoden wurde eine Kurve aufgestellt über die Beziehungen der Diazoxon-Konzentration zu der Zeit, die erforderlich ist, um irreversible Schäden der Nervenfunktion hervorzurufen. Unter Anwendung der gleichen Methoden bei der Beobachtung des Verhaltens der Ganglien in Küchenschaben, die zu bekannter Zeit vorher mit LD₉₀s von Diazoxon örtlich behandelt worden waren, konnte von der Kurve die Diazoxon-Konzentration in der Haemolymphe abgeschätzt werden, wann die Ganglien irreversibel geschädigt wurden. Irreversible Schädigung trat erst 1–2 Stunden nach der Anwendung mit einer LD₉₀ auf, und die Konzentration, die zur Erzeugung des gleichen Vergiftungsstadiums in freigelegten Ganglien in vitro in der gleichen Zeit erforderlich war (0,6–1,0 M), ähnelt eher der mittleren Konzentration (1,8 M), die durch chemische Prüfung in der Haemolymphe ähnlich behandelter Schaben gefunden wurde. Daraus folgt, daß Diazoxon von der Haemolymphe aus in die Ganglien eindringt, und daß es eher direkt wirkt statt als Umwandlungsprodukt oder durch die Entbindung eines neuroaktiven Stoffes.

     

美洲大蠊内生菌几丁质酶基因的克隆、表达及其活性研究 *

Objective: To clone the chitinase gene ChiA from the endophytes of Periplaneta americana soluble expression of the protein and to identify its function.Methods:The chitinase gene ChiA was amplified by PCR from the DNA of Serratia marcescens,which was separated from the gut of Periplaneta americana and obtained by subcloning. The expression plasmid ChiA/pET21b was constructed and analyzed by bioinformatics. The plasmid was transformed into E. coli BL21(DE3) and the postive strains were induced by IPTG at 20℃ for 20h. The bioactivity of the protein was determined by small punch test.Results:The cloned sequence was associated with Serratia marcescens ChiA gene of GenBank and their homology was 99%. The sequence encoded a protein containing of 571 amino acids and expressed stably in prokaryotic system.SDS-PAGE/Western blot show that the soluble target protein was obtained. The small punch test suggested that the target protein had the activity of decomposing chitin and was stronger than that of the Serratia marcescens.Conclusion:The chitinase gene ChiA of the Serratia marcescens from the gut of Periplaneta americana was cloned successfully. The soluble chitinase that shows marked bioactivity was attained by prokaryotic expression system, which has provided theoretical basis for its further application.     

Food and the spatial distribution of adult female pinworms parasitic in the hindgut of Periplaneta americana L.

Food and the spatial distribution of adult female pinworms parasitic in the hindgut of Periplaneta americana L. International Journal for Parasitology 4: 759–771. The spatial distribution of the two pinworms Hammerschmidtiella diesingi and Leidynema appendiculata in the adult cockroach Periplaneta americana was determined by examination of hind guts fixed by immersion in liquid air. The position of the mouths of the worms reveals that L. appendiculata favours a more anterior position and is more restricted in its distribution than H. diesingi. The position of each species in the colon is unaffected by the presence of the other species or by crowding. Moreover, the two species are segregated in terms of their radial distribution, with the mouth of H, diesingi being restricted to a position near the intima of the colon while that of L. appendiculata favours the lumen. The two nematodes differ in the structure of the stoma and pharynx which reflect a difference in their diet. The food of L. appendiculata consists of relatively large particles while that of H. diesingi is finely patticulate. The ability of these two species to coexist in the same host is explained by their longitudinal and radial distribution and by the different sources of their food.     

Biochemical changes in tissue composition of Periplaneta americana (Linn.) acclimated to high and low temperatures

1. 1.|Cold acclimation apparently favours an increase of water content in fat body, but not in coxal muscle, of cockroaches.

2. 2.|A remarkable enhancement in the accumulation of total protein in fat body characterizes the cold acclimation of cockroaches, particularly adult males (175% increase in protein/DNA ratio). The increase in protein content of coxal muscle during acclimination to 15°C, observed in nymphs (16%) and males (16%) but not in females, is less pronounced than that of fat body.

3. 3.|A diminution (28–32%) in the free amino acid/DNA ratio due to cold acclimation has been recorded in both coxal muscle and fat body of nymphs and females, but not in males.

4. 4.|No qualitative change occurs in the free amino acid spectrum of haemolymph and tissues of this insect during acclimation to 15 and 35°C.

5. 5.|An augmentation (15–30%) of the RNA/DNA ratio occurs in fat body and coxal muscle of nymphs and males but in fat body alone of females following cold acclimation.

6. 6.|The glycogen reserve has been shown to increase by up to 30% in fat body and coxal muscle of cold acclimated cockroaches compared to warm acclimated ones.

Potential of Periplaneta fuliginosa densovirus as a biocontrol agent for smoky-brown cockroach, P. fuliginosa

A densovirus, named Periplaneta fuliginosa densovirus (PfDNV), affects smoky-brown cockroach (P. fuliginosa), which is a major peridomestic cockroach in China, southeastern United States, Japan, and Southeast Asia. We reported here that PfDNV could be mass-produced using virus rescue technology. Pathology and ultrastructural studies revealed the presence of enlarged and dense nuclei in hindgut cells of infected smoky-brown cockroach nymphs and adults. Laboratory bioassays of the PfDNV against P. fuliginosa showed that it has the potential to be used as a biocontrol agent. High mortality was recorded in adult smoky-brown cockroaches treated with PfDNV baits at the dosage of 6 × 10⁴ virions per gram against P. fuliginosa in both no-choice tests and two-choice tests (LT₅₀’s were 13.37 and 13.50 days, respectively). PfDNV was also effective in large population chamber tests. LT₅₀ was 17.57 days and mortality achieved was 95.6% in 28 observation days.     

Innervation of the American cockroach salivary gland: neurophysiological and pharmacological investigations

Application of 5-hydroxytryptamine to the gland in vitro in concentrations as low as 10^?12 M effected continuous secretion of fluid. This suggests that 5-HT or a related compound may be the neurotransmitter substance. In vivo injections of p-chorophenylalanine did not affect secretion. Applications of pilocarpine and acetylcholine had only a transitory effect upon secretions. Nerve-section studies implicate the salivary duct nerves coming from the suboesophageal ganglion as motor nerves controlling secretion. The oesophageal salivary nerves from the brain were not severed due to excessive trauma. Simultaneous electrical recordings of the salivary nerves show no common activity. Nerve section demonstrates that the activity in these nerves is efferent. Central inhibition of nervous activity occurs during sensory stimulation, etc. Electrical stimulation of the salivary duct nerve in vitro effects salivary secretion for several hours; however, the loss of secretion is not due to failure of the nerves, but to unknown factors. Histological sections of the stimulated glands failed to show cytological changes.     

One trial learning in the American cockroach, Periplaneta americana

A new and simple method of training intact cockroaches was designed. (1) Cockroaches were maintained before and during the experiment with a high motivation to look for sugar. They were kept in a chamber with water and yeast extract ad libitum but without any sugar. (2) Cockroaches were individually trained to associate two artificial scent signals, i.e. menthol and vanilla, with sugar and salt solutions. Discriminatory learning performance was measured by testing the scent preference before and after training. Care was taken to exclude other than olfactory cues in the discriminatory paradigm. (3) Cockroaches exhibited a spontaneous initial preference for vanilla over menthol. This preference could be modified by training. The insect showed fast learning and long retention. One training trial was enough to reverse the initial preference with a significant retention after 7 days. Reversal of trained preference was accomplished by retraining. (4) The method provides an opportunity to study sensory performance and memory consolidation in cockroaches.     

Haemolymph lipase activity in the American cockroach, Periplaneta americana

The haemolymph of the cockroach, Periplaneta americana, has been shown to possess pronounced lipolytic activity. The enzyme may be considered a ‘true’ lipase because of its ability to hydrolyse long chain fatty acid glycerides. The enzyme exhibits dual optima at pH 4·9 and 7·0 and is inhibited by fluoride ion. Lipase activity in the intact cockroach is unaffected by the corpus cardiacum hypolipemic factor; however, prolonged periods of starvation result in a significant decline in enzyme activity.     

Quantitative structure-activity studies of octopaminergic 2-(Arylimino)thiazolidines and Oxazolidines against the nervous system of Periplaneta americana L.

The quantitative structure-activity relationship (QSAR) of octopaminergic 2-(arylimino)thiazolidines (AITs) and 2-(arylimino)oxazolidines (AIOs) against the thoracic nerve cord of the American cockroach, Periplaneta americana L., was analysed using reported physicochemical parameters and regression analysis. The more electron-donating, the less bulky at m-position, and the more hydrophobic the substituent, the greater the activity. The plots of observed log V_max values against calculated log V_max values having substituents on the m-position deviated downwards from those of compounds having substituents at the o- and/or p-positions. The more hydrophobic and the more electron-withdrawing the substituent, the greater the activity. AIO with a 2,3,4-trichlorophenyl group (58) was more active than its thiazolidine derivative, 2-(2,3,4-trichlorophenylimino)thiazolidine (38) in terms of V_max:V_max of 58 was 30% relative to octopamine (OA), whereas that of 38 has been 9% relative to OA, respectively. Superimposition of energy-minimized OA and 58 revealed structural and conformational similarities that might account for the high activity of 58.     

Circadian rhythmicity in the nervous system of the cockroach, Periplaneta americana

Diurnal rhythmicity of nervous activity in Periplaneta americana was investigated, using acetylcholine (ACh) content, acetylcholinesterase (AChE) and spontaneous electrical activities as indices. AChE and electrical activities were maximum at 0 hr and minimum at 12 hr, while ACh showed an opposite rhythm. Central nervous system extract from cockroaches at 12 hr elevated the electrical activity while 0 hr-extract exerted inhibition. Lower concentrations of ACh had an elevatory influence while higher concentrations inhibited the electrical activity. A hypothesis is proposed, suggesting synthetic and releasing phases of ACh in a regular diurnal cycle, to explain the results obtained.     

Action of two corpus cardiacal peptides on muscles of the hindgut of Periplaneta americana L. (Orthoptera: Blattidae)

1. (1) Two small, basic peptides (Ic and II) which stimulate muscles of the hindgut, but not the heart, have been separated from extracts of the corpora cardiaca by ion exchange chromatography and gel filtration.

2. (2) Results obtained with the 5-HT antagonist mianserin hydrochloride suggest that both peptides stimulate contractions of the hindgut by direct action without mediation by an indoleamine such as 5-HT.

3. (3) Extracellular calcium ions are required for rapid contractions of the hindgut stimulated by peptides Ic and II. However, the tonus response to these peptides does not appear to depend on the same inward transmembrane transport of extracellular Ca²⁺ as rapid contractions.

4. (4) Theophylline (5 mM) potentiated the action of both peptides on hindgut muscle, however, stimulation of hindgut muscle by cardiacal extract did not cause a significant increase in the level of cyclic AMP as compared with controls.

5. (5) These results more clearly define the number, character and possible action of cardiacal peptides stimulating hindgut muscle in P. americana.

     

Serotonin in the central nervous system of the cockroach, Periplaneta americana

Studies on serotonin in the insect nervous system has long been neglected, although serotonin is a putative neurotransmitter. During the course of this study the serotonin content was found to be significantly higher than that found in mammalian midbrain. Parachlorophenylalanine was found to inhibit the first step of the biosynthetic pathway by inhibiting tryptophan-hydroxylase enzyme and leading to alterations in the concentrations of metabolites such as 5-hydroxy tryptophan, 5-hydroxy indole acetic acid and tryptophan. Using a dose of 15 μg/g the inhibitory effect was not long lasting and recovery was observed to restore the normal levels. Higher trytophan levels were observed after a certain period of P-chlorophenylalanine treatment because there was a block in the biosynthetic path and tryptophan could not be utilized for 5-HT synthesis. A negative correlation between brain tryptophan and protein content was observed in both the cases of P-chlorophenylalanine and reserpine treatments.