Carbohydrate Digestion in Sandflies: α-Glucosidase Activity in the Midgut of Phlebotomus langeroni

Dillon, Rod J.; Kordy, El

doi:10.1016/s0305-0491(96)00195-2

Cited by 33 publications

(33 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In L. longipalpis, the α-glucosidase is more efficient in slightly acidic conditions, even when the enzyme is obtained from insects that are digesting blood (data not shown). In contrast, in Phlebotomus langeroni, the α-glucolytic activity described in blood-fed females has an optimal pH between 7 and 7.5 (Dillon and el-Kordy, 1997). These data indicate important physiological differences between these two phlebotomine species that deserve to be studied in more detail.…”

Section: Discussionmentioning

confidence: 76%

The physiology of the midgut ofLutzomyia longipalpis(Lutz and Neiva 1912): pH in different physiological conditions and mechanisms involved in its control

Santos

Araújo

Machado

et al. 2008

Journal of Experimental Biology

View full text Add to dashboard Cite

SUMMARYNutrient digestion and absorption after blood feeding are important events for Lutzomyia longipalpis, which uses these nutrients to produce eggs. In this context, the pH inside the digestive tract is an important physiological feature as it can markedly influence the digestive process as well as interfere with Leishmania development in infected phlebotomines. It was described previously that unfed females have an acidic midgut (pH 6). In this study, the pH inside the midgut of blood-fed females was measured. The abdominal midgut (AM) pH varied from 8.15±0.31 in the first 10 h post-blood meal to 7.7±0.17 after 24 h. While the AM was alkaline during blood digestion, the pH in the thoracic midgut (TM) remained acidic (5.5-6.0). In agreement with these findings, the enzyme α-glucosidase, which has an optimum pH of 5.8, is mainly encountered in the acidic TM. The capacity of unfed females to maintain the acidic intestinal pH was also evaluated. Our results showed the presence of an efficient mechanism that maintains the pH almost constant at about 6 in the midgut, but not in the crop. This mechanism is promptly interrupted in the AM by blood ingestion. RT-PCR results indicated the presence of carbonic anhydrase in the midgut cells, which apparently is required to maintain the pH at 6 in the midgut of unfed females. Investigations on the phenomenon of alkalization observed after blood ingestion indicated that two mechanisms are involved: in addition to the alkalization promoted by CO 2 volatilization there is a minor contribution from a second mechanism not yet characterized. Some inferences concerning Leishmania development and pH in the digestive tube are presented.

show abstract

Section: Discussionmentioning

confidence: 76%

The physiology of the midgut ofLutzomyia longipalpis(Lutz and Neiva 1912): pH in different physiological conditions and mechanisms involved in its control

Santos

Araújo

Machado

et al. 2008

Journal of Experimental Biology

View full text Add to dashboard Cite

show abstract

“…In Lepdopterans, which feed on leaves, exoglycosidase(s)-like b-glycosidases are predominantly present (Marana et al, 2000), and Hemipterans, which are plant feeders, use b-galactosidases to digest the carbohydrates present in their diet (Ferreira et al, 1998). Dipterans, which feed on blood, use alkaline a-glucosidases during meal digestion (Dillon and Kordy, 1997) and those that feed on plants, use mainly b-galactosidases (Ferreira et al, 1998). In C. capitata, the Diptera under study, high specific a-galactosidasic and b-galactosidasic activities using p-nitrophenyl glycosides, associated with enzymatic activities on maltose and sucrose, were observed in the 2nd and 3rd day of larval development.…”

Section: Discussionmentioning

confidence: 99%

Digestive enzymes during development of Ceratitis capitata (Diptera:Tephritidae) and effects of SBTI on its digestive serine proteinase targets

Silva

Alcazar

Macedo

et al. 2006

Insect Biochemistry and Molecular Biology

View full text Add to dashboard Cite

The digestive system of Ceratitis capitata was characterized during its larval development and in the insect stage. Disaccharidases against maltose and sucrose were more evident in the 2nd and 3rd day of larval development and in the adult stage, respectively. Glycosil-hydrolyses with higher specific a-galactosidasic and b-galactosidasic activities were detected in the 2nd and 3rd day of the larval stage, respectively. Specific proteolytic activities against azocasein showed an increase in the 4th and 5th day of the larval stage and in the adult stage. Specific hemoglobin activities were constant between 2nd and 6th day of the larval stage. The larvae used mainly serine proteinases, such as trypsin/chymotrypsin, and the adult insects only chymotrypsin-like enzymes in their digestive process. Two serine proteinases were separated from zymogram between the 4th and 5th day of larval development and in the adult stage. Effect of soybean trypsin inhibitor (SBTI, a serine proteinase inhibitor) on development of C. capitata was examined by bioassay. C. capitata was susceptible to SBTI which affected larval mass at ED 50 3.01%. r

show abstract

“…a-Amylase was highest in unfed¯ies and dropped after blood or sugar feeding, while no salivary a-glucosidase was detected [17]. The presence of a-glucosidase has been reported from the guts of both L. longipalpis [8] and P. langeroni [5], where the activity of this enzyme was followed after a blood or sugar meal.…”

Section: A-amylase and A-glucosidasementioning

confidence: 91%

“…The substrate p-nitrophenol a-D-glucopyranoside was used to assay a-glucosidase activity [5,10] Sucrase (b-D-fructofuranosidase EC 3.2.1.26) was ®rst described from L. donovani [1] and later was found in cultures of a wide range of pathogenic Leishmania species and other insect¯agellates, but not in several Trypanosoma species [7]. As sucrose is one of the main sources of energy for sand¯ies, it is surprising that only sucrose a-glucohydrolase (EC 3.2.1.48) is the one of the few midgut enzymes that has been characterized and only for L. longipalpis [8] and P. langeroni [5].…”

Section: Other Glycosidasesmentioning

confidence: 99%

The biological function of sand fly and Leishmania glycosidases

Schlein

2001

Med Microbiol Immunol

View full text Add to dashboard Cite

This is a summary of the recent work on some glycosidases of sand flies and their Leishmania parasites. Glycosidases catalyze the hydrolysis of complex sugar subunits of polysaccharides into simple sugars. Leishmania major parasites secrete chitinase and N-acetylglucosaminase, which enables them to survive in the gut of the sand fly and are important in facilitating their transmission by the phlebotomine sand fly Phlebotomus papatasi. These enzymes are found in a wide range of trypanosomatids and the gene locus is highly conserved. The sand flies feed on plants and the ingested tissues may contain cellulose particles that the sand flies are unable to digest. Cellulolytic enzymes are secreted by L. major promastigotes and this may help to break down cellulose in infected flies and sustain their growth. Starch is a main photosynthesis product that is stored in leaves. Starch grains have been found in the midguts of field caught sand flies and alpha-amylase, the specific enzyme for starch, has been found in the salivary glands and other organs of Lutzomyia longipalpis and P. papatasi. Alpha-amylase and alpha-glucosidase are expressed by L. major promastigotes and alpha-glucosidase is secreted by several trypanosomatid genera, but not by all those examined. Primers originally designed to amplify P. papatasi amylase DNA sequences, by polymerase chain reaction (PCR), also amplified DNA from all Old World Leishmania species, indicating that the gene is highly conserved between sand flies and these parasites.

show abstract

Carbohydrate Digestion in Sandflies: α-Glucosidase Activity in the Midgut of Phlebotomus langeroni

Cited by 33 publications

References 22 publications

The physiology of the midgut ofLutzomyia longipalpis(Lutz and Neiva 1912): pH in different physiological conditions and mechanisms involved in its control

The physiology of the midgut ofLutzomyia longipalpis(Lutz and Neiva 1912): pH in different physiological conditions and mechanisms involved in its control

Digestive enzymes during development of Ceratitis capitata (Diptera:Tephritidae) and effects of SBTI on its digestive serine proteinase targets

The biological function of sand fly and Leishmania glycosidases

Contact Info

Product

Resources

About