Insulin in insects: Analysis of immunoreactivity in tissue extracts

Teller, Jan K.; Pilc, L.

doi:10.1016/0305-0491(85)90348-7

Cited by 7 publications

(2 citation statements)

References 16 publications

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“…Many attempts have been made to localize insulin immunoreactivity in the insect midgut, but these experiments and their conclusions have been severely criticized (e.g., Yalow and Eng 1981;Teller and Pilc 1985;Veenstra 1989a). Within this context, we consider it to be of interest to investigate the possible expression of the Drosophila insulin genes in the midgut.…”

Section: Peptide Identificationmentioning

confidence: 99%

Regulatory peptides in fruit fly midgut

2008

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Regulatory peptides were immunolocalized in the midgut of the fruit fly Drosophila melanogaster. Endocrine cells were found to produce six different peptides: allatostatins A, B and C, neuropeptide F, diuretic hormone 31, and the tachykinins. Small neuropeptide-F (sNPF) was found in neurons in the hypocerebral ganglion innervating the anterior midgut, whereas pigment-dispersing factor was found in nerves on the most posterior part of the posterior midgut. Neuropeptide-F (NPF)-producing endocrine cells were located in the anterior and middle midgut and in the very first part of the posterior midgut. All NPF endocrine cells also produced tachykinins. Endocrine cells containing diuretic hormone 31 were found in the caudal half of the posterior midgut; these cells also produced tachykinins. Other endocrine cells produced exclusively tachykinins in the anterior and posterior extemities of the midgut. Allatostatin-immunoreactive endocrine cells were present throughout the midgut. Those in the caudal half of the posterior midgut produced allatostatins A, whereas those in the anterior, middle, and first half of the posterior midgut produced allatostatin C. In the middle of the posterior midgut, some endocrine cells produced both allatostatins A and C. Allatostatin-C-immunoreactive endocrine cells were particularly prominent in the first half of the posterior midgut. Allatostatin B/MIP-immunoreactive cells were not consistently found and, when present, were only weakly immunoreactive, forming a subgroup of the allatostatin-C-immunoreactive cells in the posterior midgut. Previous work on Drosophila and other insect species suggested that (FM)RFamide-immunoreactive endocrine cells in the insect midgut could produce NPF, sNPF, myosuppressin, and/or sulfakinins. Using a combination of specific antisera to these peptides and transgenic fly models, we showed that the endocrine cells in the adult Drosophila midgut produced exclusively NPF. Although the Drosophila insulin gene Ilp3 was abundantly expressed in the midgut, Ilp3 was not expressed in endocrine cells, but in midgut muscle.

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Section: Peptide Identificationmentioning

confidence: 99%

Regulatory peptides in fruit fly midgut

2008

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“…Insulin-like factors have been demonstrated by immunological techniques in a variety of insect species (Tager et al, 1976;Duve & Thorpe, 1979;Yui, Fujita & Ito, 1980;El-Salhy et al, 1980Veenstra et al, 1985). Although the use of insulin radioimmunoassays in insect tissue extracts without appropriate control of protease activity has been criticized (Thorpe & Duve, 1984;Teller & Pilc, 1985), and it has been shown that the large-size molecular weight ' insulin-like ' immunoreactive substances are probably proteases (Teller & Pilc, 1985), it is clear from the characterization of some * Present address: Department of Entomology, 434 Forbes, Bldg no. 36, The University of Arizona, Tucson, A 2 85721, USA.…”

Section: Introductionmentioning

confidence: 99%

Do Insects Really Have a Homeostatic Hypotrehalosaemic Hormone?

Veenstra

1989

Biological Reviews

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Since trehalose in insects, in contrast to glucose in mammals, does not enter the haemolymph directly from the digestive tract, but is all synthesized by the insect itself, and furthermore an increased trehalose synthesis during stress and flight does not lead to significant increases in haemolymph trehalose, there seems to be no physiological need for an insect homeostatic hypotrehalosaemic hormone. Experiments in which tissue extractions were found to lower haemolymph trehalose can not prove the existence of such a hormone, while all insect species which so far have been submitted to a trehalose-tolerance test, decrease their haemolymph trehalose concentrations at a rate which can be accounted for by the metabolic use of trehalose. These results therefore indicate the absence, and not the presence, of a homeostatic hypotrehalosaemic hormone. This is also true for blowflies, from which an insulin-like immunoreactive peptide has been isolated. It seems therefore unlikely that this insulin-like peptide is a homeostatic hypotrehalosaemic hormone. The physiological mechanism by which this insulin-like peptide would have to act to function as a hypotrehalosaemic hormone is also an unlikely one. It therefore seems justified to conclude that so far, homeostatic hypotrehalosaemic hormones have not been demonstrated in insects. Furthermore, it may well be that they do not exist.

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A hypoglycemic factor from the corpus cardiacum of the american cockroach Periplaneta americana

Barrett

Loughton

1987

General and Comparative Endocrinology

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Insulin in insects: Analysis of immunoreactivity in tissue extracts

Cited by 7 publications

References 16 publications

Regulatory peptides in fruit fly midgut

Regulatory peptides in fruit fly midgut

Do Insects Really Have a Homeostatic Hypotrehalosaemic Hormone?

A hypoglycemic factor from the corpus cardiacum of the american cockroach Periplaneta americana

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