Cockroach Fat Body Research Articles

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

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+.

X-ray microanalysis of cockroach fat body in relation to ion and water regulation

X-Ray microanalysis of fat body from the cockroach ( Periplaneta americana) showed that the crystals in the urate cells sequestered potassium and sodium during water deprivation. Postassium sequestration appeared to occur by the formation of additional crystals whereas sodium appeared to be taken up by pre-existing crystals of the “amorphous granule” type. Urate cells increased in cytoplasmic density i.e. mass per unit volume as a result of water deprivation and lost potassium from the cytoplasm but not from the nucleus. Trophocyte cells also showed an increase in density and a loss of potassium from the cytoplasm. The nucleus in trophocyte cells however, did not increase in density and showed an increase in chlorine concentration. A previously undescribed type of crystal in the trophocyte cell cytoplasm also increased markedly in chlorine concentration. The mycetocyte cells did not appear to increase in density but chlorine concentration was elevated in symbionts, cytoplasm and nucleus. An increase in density is considered to be a consequence of a reduction in volume due to water loss. It is confirmed that the fat body plays a major role in the maintenance of ion balance during water deprivation.

Experimental life-cycle studies of Raillietiella gehyrae Bovien, 1927 and Raillietiella frenatus Ali, Riley and Self, 1981: pentastomid parasites of geckos utilizing insects as intermediate hosts

SUMMARYThe life-cycles of two closely related cephalobaenid pentastomids, Raillietiella gehyrae and Raillietiella frenatus, which utilize geckos as definitive hosts and cockroaches as intermediate hosts, have been investigated in detail. Early development in the fat-body of cockroaches involves 2 moults to an infective, 3rd-stage larva which appears from 42–44 days post-infection. Complete development in geckos involves a further 5 moults in the case of males and 6 for females. Males mature precociously and copulation is a once-in-a-lifetime event which occurs around day 80 post-infection when both sexes are the same size but the uterus of the female is undeveloped. Sperm, stored in the spermathecae, is used to fertilize oocytes which slowly accumulate in the developing saccate uterus. Patency commences when the uterus carries approximately 4000–5500 eggs but only 25–36 % of these contain fully developed primary larvae. Since only mature eggs are deposited, we postulate that the vagina (?) of the female must be equipped with a selective filter that allows through large eggs but retains smaller, immature eggs. Thus the only limit on fecundity is the total number of sperms in the spermathecae and this is precisely the same factor that constrains egg production in the advanced order Porocephalida.

The role of extracellular calcium in hormonal activation of glycogen phosphorylase in cockroach fat body

Activation of phosphorylase in intact fat body of the cockroach, Periplaneta americana, by trehalagon (hyperglycaemic, hypertrehalosemic hormone) is absolutely dependent on Ca 2+ in the extracellular medium. Maximum activation was attained within 5 min by 1.8 mM Ca 2+ which is within the concentration range found in haemolymph. Mn 2+ could replace Ca 2+ in the salt solution but Mg 2+ was ineffective. In the absence of trehalagon, phosphorylase could be maximally activated by theophylline and cyclic AMP (10 μM). The action of both substances required Ca 2+. Theophylline exhibited an unusual effect in that activation by 1 mM theophylline was totally dependent on Ca 2+ whereas that by 10 mM was only 50% dependent. The calcium ionophore A-23187 is as effective as the hormone in activating phosphorylase but exhibited only a weak stimulatory effect on trehalose output, the rate returning to the basal level after approx 5 min. Activation of phosphorylase by trehalagon was completely blocked by inclusion of 1 mM La 3+ in the salt solution. The same procedure also reduced the rate of trehalose output from trehalagon stimulated tissue to the basal rate. The results suggest that activation of phosphorylase by trehalagon is the result of an increase in phosphorylase kinase activity caused by a rise in intracellular Ca 2+ levels. Cyclic AMP is thought to play a role in regulating the Ca 2+ permeability of the fat body cell membrane.

X-ray microanalysis of freeze-substituted cockroach fat body: Na + accumulation during water deprivation

X-ray microanalysis of freeze-substituted cockroach fat body: Na + accumulation during water deprivation

Uric Acid Quantities in the Fat Body of Normal and Aposymbiotic German Cockroaches, Blattella germanica

Uric acid was measured in fat body of several age groups of the German cockroach, Blattella germanica (L.). Fat body was dissected from insects and dried to constant weight; uric acid was measured on a percentage dry weight basis using an enzyme-specific assay with uricase. Aposymbiotic last stage nymphs contained about twice as much uric acid as normal nymphs (means of 48 and 23%, respectively). Uric acid increased with high significance in normal nymphs during the last stage. There was a marginally significant increase (mean of 54%) with age in aposymbiotic adult females, while normal adult females showed a highly significant increase and much greater variation (between 18 and 87%) than the other groups tested. Both adult normal and adult aposymbiotic males showed increases in uric acid with age in asymptotic fashion, approaching mean maximum values of about 72 and 81%, respectively.

Trehalose production in isolated fat body of the american cockroach, Periplaneta americana

1. The trehalogenic capacity of incubating fat body tissue may be expressed in terms of the trehalogenic index (Trehalose produced during incubation/Trehalose produced + Glycogen remaining after incubation). 2. Pieces of fat body from the same individual have comparable trehalogenic indexes. 3. The trehalogenic index is relatively independent of pH flux in the incubating medium. 4. The trehalogenic index is elevated by calcium, but not by magnesium, whereas potassium ions tend to depress the trehalogenic index. 5. Aqueous extracts of corpora cardiaca, 10 −4 M octopamine and 10 −4M dopamine increase the trehalogenic index, whereas 10 −4 M tyramine causes the trehalogenic index to decrease.

Elevation of adenosine 3′,5′-monophosphate by octopamine in fat body of the american cockroach, Periplaneta americana L

1. 1. dl-Octopamine causes a rapid elevation of adenosine 3′,5′-monophosphate (cyclic AMP) in incubating fat body of Periplaneta americana. 2. 2. The effect is maximal at about 10 min. 3. 3. Octopamine-induced elevation of fat body cyclic AMP levels is obtained with an octopamine concentration of 10 −6 M. 4. 4. Octopamine also stimulates the production of trehalose by fat body at a concentration of 10 −6 M. 5. 5. The octopamine-sensitive adenylate cyclase receptor displays pharmacological similarities to α-adrenergic receptors of vertebrates.

Isolation and identification of the metabolites of 22,25 dideoxyecdysone from cockroach fat body cultures

Hydroxylation and conjugation were the principal pathways of metabolism of 22,25-dideoxyecdysone in cockroach fat body cultures. The major metabolite isolated and identified was the tetrahydroxy steroid 22-deoxyecdysone; other exdysteroids isolated, in order of decreasing quantities, were 22-deoxy-26-hydroxyecdysone, 22,25-dideoxy-26-hydroxyecdysone, and 22-deoxy-20-hydroxyecdysone. Cockroach fat body from late-instar nymphs appears to lack the mechanism for hydroxylating at C-22. Radioanalyses of the material obtained from enzymic hydrolysis of the conjugate fraction showed 65, 15 and 20% of tetraols, pentaols, and unhydrolyzed conjugates respectively, and no 22,25-dideoxyecdysone. An azasteroid and two nonsteroidal amines that effectively inhibit the activity of 22,25-dideoxyecdysone in the cockroach leg regenerate-fat body culture system enhanced the metabolism of 22,25-dideoxyecdysone, decreased the quantity of the pentaol fraction present, and caused an increase or accumulation of the tetraol and conjugate fractions in the fat body culture system.

Isolation and identification of the metabolites of 22,25-dideoxyecdysone from cockroach fat body cultures.

Hydroxylation and conjugation were the principal pathways of metabolism of 22,25-dideoxyecdysone in cockroach fat body cultures. The major metabolite isolated and identified was the tetrahydroxy steroid 22-deoxyecdysone; other exdysteroids isolated, in order of decreasing quantities, were 22-deoxy-26-hydroxyecdysone, 22,25-dideoxy-26-hydroxyecdysone, and 22-deoxy-20-hydroxyecdysone. Cockroach fat body from late-instar nymphs appears to lack the mechanism for hydroxylating at C-22. Radioanalyses of the material obtained from enzymic hydrolysis of the conjugate fraction showed 65, 15 and 20% of tetraols, pentaols, and unhydrolyzed conjugates respectively, and no 22,25-dideoxyecdysone. An azasteroid and two nonsteroidal amines that effectively inhibit the activity of 22,25-dideoxyecdysone in the cockroach leg regenerate-fat body culture system enhanced the metabolism of 22,25-dideoxyecdysone, decreased the quantity of the pentaol fraction present, and caused an increase or accumulation of the tetraol and conjugate fractions in the fat body culture system.

Development and endocrine regulation of mitochondrial cytochrome biosynthesis in the insect fat body: δ-[ 14C]aminolevulinic acid incorporation

The rate of incorporation of [ 14C]aminolevulinic acid (ALA) into cytochrome hemes was used to measure mitochondrial cytochrome synthesis in the fat body of adult male Blaberus discoidalis cockroaches. The hemes of cytochromes aa 3+ b and c+ c 1, were chemically separated to observe differential rates in their synthesis and regulation. [ 14C]ALA was linearly incorporated into cytochrome hemes for at least 8 h. No significant pool of endogenous ALA was detected relative to the amount of administered [ 14C]ALA. Peak cytochrome synthesis occurred 4 to 6 days after adult emergence. Endocrine disruption by corpora cardiaca-corpora allata extirpation or cervical ligation eliminated the 4-day developmentally related increase in the rate of cytochrome aa 3+ b synthesis but had no effect on the production of cytochromes c+ c 1. Injections of corpora cardiaca extracts into cervically ligated animals stimulated the rate of production of cytochromes aa 3+ b by 2.5 times but did not affect cytochromes c+ c 1. By comparison, juvenile hormone injections did not affect the rate of synthesis of either cytochrome fraction. These findings indicate that a neurohormone regulates the rate of synthesis of cytochromes a+ b in insect fat body mitochondria.

Intracellular distribution of enzymes associated with lipogenesis and gluconeogenesis in fat body of the adult cockroach, Periplaneta

The intracellular distribution and maximal activities of some enzymes associated with lipogenesis, gluconeogenesis and fatty acid oxidation have been determined in the fat body of the adult male cockroach Periplaneta americana. Of the enzymes of lipogenesis, acetyl-CoA synthase, acetyl-CoA carboxylase, glucose 6-phosphate dehydrogenase, and ATP citrate lyase are located entirely in the cytosol. Of the other enzymes of citrate metabolism studied, citrate synthase and NAD-dependent isocitrate dehydrogenase are almost exclusively mitochondrial, whereas NADP-dependent isocitrate dehydrogenase and aconitase are predominantly cytosolic although significant mitochondrial activity is also present. The latter subcellular distribution is also observed for ‘malic enzyme’ and NAD and NADP dependent malate dehydrogenase. The enzyme of fatty acid oxidation studied, 3-hydroxyacyl-CoA dehydrogenase is entirely mitochondrial. Of the enzymes possibly involved in gluconeogenesis, glucose 6-phosphate is microsomal, fructose 1,6-diphosphatase cytosolic, pyruvate carboxylase mitochondrial and phosphoenolpyruvate carboxykinase predominantly cytosolic. Of the enzymes of amino acid metabolism studied, glutamate dehydrogenase is NAD-dependent and located in the mitochondria whereas glutamate/oxalacetate and glutamate/pyruvate transaminases are predominantly cytosolic but with significant activity in the mitochondria. Glycerol kinase and sorbitol dehydrogenase are cytosolic and the glyoxylate cycle enzymes malate synthetase and isocitrate lyase are not detected in the fat body. The distribution and relative activities of the enzymes are discussed in relation to fat body biosynthesis and in comparison to mammalian liver and adipose tissue.

The intracellular distribution of enzymes of carbohydrate degradation in the fat body of the adult male cockroach

The intracellular distribution and maximal activities of phosphorylase, trehalase, all the enzymes of glycolysis, NAD and FAD-linked glycerol 3-phosphate dehydrogenase, arginine kinase, and adenylate kinase have been determined in the fat body of the adult male cockroach Periplaneta americana. Phosphorylase activity is predominantly in the soluble form but some can be sedimented. Both forms of the enzyme exhibit large increases in activity due to the presence of AMP. Only low activities of trehalase are detected and the enzyme appears to exist in both active and inactive forms. FAD-linked glycerol 3-phosphate dehydrogenase is only found in the mitochondria whereas the NAD-linked enzyme and the glycolytic enzymes are located entirely in the cytosol. Of the glycolytic enzymes, phosphoglucomutase, phosphofructokinase and aldolase exhibit unusually low activities. The results suggest that conversion of hexose to triose phosphate may occur predominantly via the pentose phosphate pathway and not via glycolysis. Whereas considerable activities of both types of glycerol-3-phosphate dehydrogenase are present in the fat body only low activities of lactate dehydrogenase are detected in the tissue.

Flavin linked azoreductases of the madagascar cockroach, Gromphadorhina portentosa

Azo, nitro, and other reductases occur in midgut, fat body, gastric caecae and Malphighian tubules of the Madagascar cockroach. In midgut they are found in soluble fractions and those corresponding to mitochondria and microsomes. The azoreduction is non enzymatic. It results from the action of reduced flavin which is enzymatically produced by pyridine nucleotide dependent enzymes.

Identification and measurement of [formula omitted]-inositol in the American cockroach, [formula omitted

chiro -Inositol has been identified as a fat body and hemolymph constituent in the cockroach Periplaneta americana L. by gas chromatography and mass spectrometry. This is the first time this inositol has been observed in animal tissues. chiro -Inositol was measured along with myo- and scyllo -inositols in the cockroach fat body and hemolymph by the mass spectrometric selective ion detection technique.

Oxidative metabolism of diazinon by microsomes from rat liver and cockroach fat body

Metabolism of 32P-, ethyl-1- 14C-, and pyrimidine-2- 14C-labeled diazinon was studied using microsomal preparations from rat liver and American cockroach fat body. The oxidation of diazinon by both microsomal enzyme systems fortified with NADPH or NADH occurred through desulfuration, hydroxylation of the ring-alkyl side chain, and cleavage of the aryl phosphate bond. The major metabolic products of diazinon were hydroxydiazinon, diazoxon, and hydroxydiazoxon, which were all biologically active, and the others were identified as 2-isopropyl-4-methyl-6-hydroxypyrimidine, 2-(2′-hydroxy-2′-propyl)-4-methyl-6-hydroxypyrimidine, diethyl phosphorothioic acid, and diethyl phosphoric acid which were all produced by the cleavage of the aryl phosphate bond. The rat liver enzyme system showed a higher rate of the oxidative metabolism of diazinon than the American cockroach fat body system. EDTA stimulated the overall metabolism of diazinon. Especially the accumulation of diaxoxon from diazinon and that of hydroxydiazoxon from both diazoxon and hydroxydiazinon in the rat liver microsomal system were stimulated by EDTA. On the basis of these in vitro studies, the general pathways of oxidative metabolism of diazinon in the mammal and the insect were presented.

Enzymatic conjugation of diazinon with glutathione in rat and American cockroach

The mechanism of cleavage of the pyrimidinyl-phosphate bond of 32P- and pyrimidine-2- 14C-labeled diazinon or 32P-labeled diazoxon by soluble enzyme preparations from rat liver and fat body of American cockroach was studied. The reaction products were identified as diethyl phosphorothioic acid and S-(2-isopropyl-4-methyl-6-pyrimidinyl) glutathione, which were formed by conjugation of reduced glutathione and the pyrimidinyl moiety of diazinon with the simultaneous cleavage of the phosphate ester bond. Several tissues in cockroach and rat were active in this conjugation, but the highest activity was found in the fat body and the liver. The glutathione S-transferase catalyzing the conjugation was specific for glutathione, and could not be replaced by other SH compounds. Diazoxon, n-propyl, and isopropyl diazinons having the structure similar to diazinon were also cleaved to give the glutathione conjugates. The pH optimum was 6.5 for the fat body and 6.0 for the liver enzyme. Both enzymes were inhibited by various SH reagents, oxidized glutathione, and some chelating agents. The fat body enzyme showed marked sensitivity to inhibition by o-phenanthroline.

Fluctuation of protein granules in the fat body of the viviparous cockroach, Diploptera punctata, during the reproductive cycle

Protein storage granules of the abdominal fat body of the adult viviparous cockroach, Diploptera punctata were identified histochemically and the relative numbers were estimated at intervals throughout the reproductive cycle of mated females and in virgin females and males of the same age. Granules were counted in sections of the fat body and alternately the total quantity of protein was determined by the Lowry modification of the Folin method after removal of uric acid. Protein granule storage is clearly correlated with the reproductive cycle of mated females. The granules disappear during vitellogenesis and reappear during the gestation period. Virgin females which mature eggs sporadically and much later than mated females show a cyclic depletion and repletion of granules related in pattern to that of mated females but about 30 days shorter. Males also show a depletion of granules at ecdysis, followed by a repletion. There was more variation among individuals of the same age in males and virgin females than there was in mated females during the first reproductive cycle. It is speculated that the juvenile hormone which is necessary for vitellogenesis also controls depletion of protein granules from the fat body.

Role of intracellular symbionts in the fatbody of cockroaches: influence of hemolymph proteins.

Zur Herabsetzung der Anzahl von Symbionten in einem Fettkorper der KuchnschabeBlaberus craniifer wurde eine Penicillin-G-Behandlung durchgefuhrt, was eine Reduktion bei 2 Hamolymphe-Proteinen verursachte. Diese mit der Symbionten-Aktivitat und Fortpflanzung verknupften Proteine treten am Ende der Behandlung wieder in Erscheinung.

Diapause Metabolism and Rearing Methods for the White-Lined Sphinx, Celerio lineata (Lepidoptera: Sphingidae)1

Recent findings indicate hormones from the braincorpora cardiaca complex may affect respiratory functions of cockroach fat body mitochondria (Keeley and Friedman 1969). A similar situation is seen in diapause which is both hormonally controlled and accompanied by prominent mitochondrial changes. The onset and termination of diapause in insects is regulated by neurosecretions from the brain (Williams 1952, DeWilde and DeBoer 1969), and during diapause, respiratory metabolism decreases to ⅙–1/20 of the normal rate (Schneiderman and Williams 1953, Adkisson et al. 1963, Stegwee 1964). This respiratory decrease is accompanied by both degeneration in mitochondrial ultrastructure and loss of enzymes, especially the cytochromes (Shappirio and Williams 1957, Stegwee 1964, Willis 1966). Because of these large responses, insects in diapause appear to be ideal subjects for studies on hormone-mitochondrial relationships.