Excretion in the Blood-Sucking Bug, Rhodnius Prolixus Stål

1963 ◽  
Vol 40 (2) ◽  
pp. 247-256 ◽  
Author(s):  
S. H. P. MADDRELL
Keyword(s):  
Instar Larva ◽  
Neurosecretory Cells ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Low Level ◽  
Blood Sucking

1. The mechanism underlying diuresis in Rhodnius has been investigated. 2. An isolated preparation of the Malpighian tubules of a 5th-instar larva is described. 3. The rate of secretion by such a preparation, isolated in a drop of haemolymph, is at first high but soon falls to a low level. It can be restored by the addition of haemolymph taken from an insect during diuresis. 4. It has been shown that diuresis is promoted by some substance, presumably a neurohormone, which can be extracted from the posterior neurosecretory cells of the fused ganglionic mass situated in the mesothorax.

scholarly journals Nitric oxide loading of the salivary nitric-oxide-carrying hemoproteins (nitrophorins) in the blood-sucking bug Rhodnius prolixus.

1995 ◽  
Vol 198 (5) ◽  
pp. 1093-1098
Author(s):  
R H Nussenzveig ◽  
D L Bentley ◽  
J M Ribeiro
Keyword(s):  
Nitric Oxide ◽  
Epithelial Cells ◽  
Salivary Glands ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Nadph Diaphorase ◽  
No Production ◽  
Synthetase Activity ◽  
Diaphorase Activity ◽  
Blood Sucking

The salivary glands of the blood-sucking bug Rhodnius prolixus are formed by a single layer of binucleated epithelial cells surrounded by a double layer of transversely oriented smooth muscle cells. The epithelial cells are rich in rough endoplasmic reticulum and mitochondria and have abundant microvillar projections towards the gland lumen. This cell layer surrounds a relatively large cavity where abundant secretory material is stored. Epithelial cells produce an intense and generalized NADPH diaphorase reaction, in contrast to other tissues such as brain, Malpighian tubules and skeletal muscle. Ultrastructural analysis of the osmiophilic reaction product indicates that it is localized within cytoplasmic vacuoles, a similar location to that of NADPH diaphorase (NO synthetase) activity in neuronal cells of vertebrates. Measurements of the time course of protein accumulation, NADPH diaphorase activity and the degree of nitrosylation of hemoproteins (nitrophorins) in the salivary glands of Rhodnius prolixus nymphs after a blood meal indicate that the nitrophorins are synthesized and accumulate when NO production is low (with a 25% loading of the nitrophorins during the fourth- to fifth-instar molt). NO loading of the nitrophorins increases to 90% after the molt, concomitant with a large increase in the salivary NADPH diaphorase activity. It is concluded that synthesis of NO occurs within the epithelial cells while the nitrophorins are stored extracellularly. It is hypothesized that the luminally oriented microvilli may serve as a diffusion bridge to direct intracellularly produced NO into the luminal cavity, where the nitrophorins are stored.

Excretion in the Blood-Sucking Bug, Rhodnius Prolixus Ståal

1964 ◽  
Vol 41 (1) ◽  
pp. 163-176 ◽  
Author(s):  
S. H. P. MADDRELL
Keyword(s):  
Underlying Mechanism ◽  
Rapid Onset ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Maximum Response ◽  
Diuretic Hormone ◽  
Blood Sucking ◽  
Constant Rate

1. The course of diuresis in Rhodnius is described and interpreted in terms of the underlying mechanism. 2. The rapid onset of diuresis is attributable to the prompt release of the diuretic hormone into the haemolymph and to an acceleration of the circulation of the haemolymph caused by peristaltic movements of the mid-gut. 3. Diuresis proceeds at a surprisingly constant rate. This is shown to be a reflexion of the fact that the concentration of the diuretic hormone in the haemolymph at this time is always higher than that which causes the maximum response by the Malpighian tubules. 4. The diuretic hormone is quickly destroyed by the activity of the Malpighian tubules and possibly other tissues. Consequently, the extent of diuresis is controlled by the length of time during which diuretic hormone is released into the haemolymph. 5. Excretion is very sensitive to changes in temperature; both the rate of excretion and the composition of the urine are affected.

The regulation of haemolymph potassium activity during initiation and maintenance of diuresis in fed Rhodnius prolixus

1993 ◽  
Vol 177 (1) ◽  
pp. 273-285 ◽  
Author(s):  
S. H. Maddrell ◽  
M. J. O'Donnell ◽  
R. Caffrey
Keyword(s):  
Opposite Direction ◽  
Major Element ◽  
Potassium Concentration ◽  
Fluid Secretion ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Blood Sucking ◽  
Potassium Absorption ◽  
Stimulation Of

The blood-sucking insect Rhodnius prolixus rapidly eliminates a Na(+)-rich K(+)-poor urine after its large meals. K(+)-rich fluid is first secreted by the upper Malpighian tubules and passes to the lower tubules where most of the potassium is reabsorbed. During the initial stimulation of the tubules, the lower tubules must be activated first to avoid loss of potassium. The major element in this is that they respond more rapidly than do the upper tubules to particular hormonal concentrations rather than that they react to lower hormonal concentrations than do the upper tubules. During subsequent diuresis, regulation of the haemolymph potassium concentration depends on three cooperative homoeostatic mechanisms in the tubules. A fall in potassium concentration of the medium bathing the tubules causes (i) a decrease in the rate of fluid secretion by the upper tubules, (ii) a decrease in potassium concentration in the fluid secreted by the upper tubules and (iii) an increase in the rate of potassium absorption by the lower tubules. The tubules respond in the opposite direction to an increase in potassium concentration of the medium. As a result, the potassium concentration of the urine can be adjusted to match the potassium concentration of the fluids absorbed from the gut, so that the potassium concentration of the insect's haemolymph remains unaltered.

scholarly journals The distribution of a CRF-like diuretic peptide in the blood-feeding bug Rhodnius prolixus

1999 ◽  
Vol 202 (15) ◽  
pp. 2017-2027 ◽  
Author(s):  
V.A. Te Brugge ◽  
S.M. Miksys ◽  
G.M. Coast ◽  
D.A. Schooley ◽  
I. Orchard
Keyword(s):  
Cyclic Amp ◽  
Malpighian Tubule ◽  
Immunogold Labelling ◽  
Blood Feeding ◽  
Neurosecretory Cells ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Double Labelling ◽  
Neurohaemal Areas ◽  
The Brain

The blood-feeding bug Rhodnius prolixus ingests a large blood meal, and this is followed by a rapid diuresis to eliminate excess water and salt. Previous studies have demonstrated that serotonin and an unidentified peptide act as diuretic factors. In other insects, members of the corticotropin-releasing factor (CRF)-related peptide family have been shown to play a role in post-feeding diuresis. Using fluorescence immunohistochemistry and immunogold labelling with antibodies to the Locusta CRF-like diuretic hormone (Locusta-DH) and serotonin, we have mapped the distribution of neurones displaying these phenotypes in R. prolixus. Strong Locusta-DH-like immunoreactivity was found in numerous neurones of the central nervous system (CNS) and, in particular, in medial neurosecretory cells of the brain and in posterior lateral neurosecretory cells of the mesothoracic ganglionic mass (MTGM). Positively stained neurohaemal areas were found associated with the corpus cardiacum (CC) and on abdominal nerves 1 and 2. In addition, Locusta-DH-like immunoreactive nerve processes were found over the posterior midgut and hindgut. Double-labelling studies for Locusta-DH-like and serotonin-like immunoreactivity demonstrated some co-localisation in the CNS; however, no co-localisation was found in the medial neurosecretory cells of the brain, the posterior lateral neurosecretory cells of the MTGM or neurohaemal areas. To confirm the presence of a diuretic factor in the CC and abdominal nerves, extracts were tested in Malpighian tubule secretion assays and cyclic AMP assays. Extracts of the CC and abdominal nerves caused an increase in the rate of secretion and an increase in the level of cyclic AMP in the Malpighian tubules of fifth-instar R. prolixus. The presence of the peptide in neurohaemal terminals of the CC and abdominal nerves that are distinct from serotonin-containing terminals indicates that the peptide is capable of being released into the haemolymph and that this release can be independent of the release of serotonin.

Fine Structure of the Malpighian Tubules of the Mosquito, Culex pipiens

1971 ◽  
Vol 29 ◽  
pp. 402-403
Author(s):  
Brendan Clifford
Keyword(s):  
Fine Structure ◽  
Culex Pipiens ◽  
Stellate Cell ◽  
Malpighian Tubule ◽  
Cell Types ◽  
Instar Larva ◽  
Malpighian Tubules ◽  
Calliphora Erythrocephala ◽  
Distinct Cell ◽  
Basal Plasma

An ultrastructural investigation of the Malpighian tubules of the fourth instar larva of Culex pipiens was undertaken as part of a continuing study of the fine structure of transport epithelia.Each of the five Malpighian tubules was found to be morphologically identical and regionally undifferentiated. Two distinct cell types, the primary and stellate, were found intermingled along the length of each tubule. The ultrastructure of the stellate cell was previously described in the Malpighian tubule of the blowfly, Calliphora erythrocephala by Berridge and Oschman.The basal plasma membrane of the primary cell is extremely irregular, giving rise to a complex interconnecting network of basal channels. The compartments of cytoplasm entrapped within this system of basal infoldings contain mitochondria, free ribosomes, and small amounts of rough endoplasmic reticulum. The mitochondria are distinctive in that the cristae run parallel to the long axis of the organelle.

Ultrastructural Characterization of Malpighian Tubules of Rhodnius prolixus During the Insect's Feeding Cycle and Under Hyperosmotic Shock

2020 ◽  
Vol 129 (2) ◽  
pp. 189
Author(s):  
Jacenir Reis dos Santos-Mallet ◽  
Simone Patrícia Carneiro Freitas ◽  
Maria Luiza Ribeiro de Oliveira ◽  
Alice Helena Ricardo-Silva ◽  
Aníbal Gil Lopes ◽  
...  
Keyword(s):  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Hyperosmotic Shock ◽  
Ultrastructural Characterization ◽  
Feeding Cycle

scholarly journals The climbing organ of an insect, Rhodnius prolixus (Hemiptera; Reduviidœ)

1932 ◽  
Vol 111 (772) ◽  
pp. 364-376 ◽  
Keyword(s):  
Mode Of Action ◽  
Ventral Surface ◽  
Rhodnius Prolixus ◽  
Blood Sucking ◽  
New Type

Adhesive or climbing organs are familiar structures in many groups of insects. Most commonly, as in Hymenoptera, Diptera and many Hemiptera, they take the form of empodia or pulvilli between the tarsal claws; in a few Hemiptera they occur at the lower end of the tibia (Weber, 1930), while in many Coleoptera and Orthoptera it is the ventral surface of the tarsal segments themselves which is specially modified (Dewitz, 1884). These structure are generally stated to be absent in the Reduviidæ, but one of us (Gillett, 1932) has recently observed a new type of climbing organ in the blood-sucking reduviid bug, Rhodnius prolixus stål. The object of the present paper is to describe the structure of this organ and to discuss its mode of action.

Hydrogen peroxide detoxification in the midgut of the blood-sucking insect,Rhodnius prolixus

2001 ◽  
Vol 48 (2) ◽  
pp. 63-71 ◽  
Author(s):  
Marcia Cristina Paes ◽  
Mariana Borges Oliveira ◽  
Pedro L. Oliveira
Keyword(s):  
Hydrogen Peroxide ◽  
Rhodnius Prolixus ◽  
Blood Sucking

Effects of the cyclopeptide mycotoxin destruxin A on the Malpighian tubules of Rhodnius prolixus (Stål)

Toxicon ◽  
2010 ◽  
Vol 55 (6) ◽  
pp. 1162-1170 ◽  
Author(s):  
Esau Ruiz-Sanchez ◽  
Ian Orchard ◽  
Angela B. Lange
Keyword(s):  
Rhodnius Prolixus ◽  
Malpighian Tubules
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