Hormonal body temperature regulation in passive and active hyperthermia

Zusammenfassung Geraten Tiere durch abnorm hohe Umgebungstemperatur in einepassive Hyperthermie, so kann, wie man weiß, in ihrem Blutserum das oxydationshemmende Schilddrüsenhormon (Thermothyrin A) nachgewiesen werden. Wird dagegen durch Wärmestich eineaktive Hyperthermie hervorgerufen, dann läßt sich in den Seren der fiebernden Tiere keine stoffwechseldämpfende Substanz nachweisen. Dieser Befund ist ein weiterer, in das Kapitel «hormonale Wärmeregulierung» gehörender Beitrag zur Frage der Verschiedenheit von aktiver und passiver Hyperthermie.     

Types of response of insects on treatment with juvenile hormone active insect growth regulators

Summary The reactions of immature insects of more than 40 species placed in continuous contact with high doses of juvenile hormone active insect growth regulators were analyzed. 4 different types were recognized: Inhibition of both ecdysis and metamorphosis, defective metamorphosis, defective adult emergence and defective embryogenesis. The reactions are understood as a consequence of JH/ecdysone antagonism. The limits for the practical application of these substances are discussed.Acknowledgments. We wish to express our thanks to Miss M. Kälin, Miss M. Lehner, Mrs T. Mühle and Mr P. Müller for technical assistance and to Prof. G. Benz, Mr M. Gruber, Dr E. Günthart and Prof H. A. Schneiderman for helpful discussion and correction of the text.     

Expression of defensins in non-infected araneomorph spiders

Defensins are a major family of antimicrobial peptides found throughout the phylogenetic tree. From the spider species: Cupiennius salei, Phoneutria reidyi, Polybetes pythagoricus, Tegenaria atrica, and Meta menardi, defensins belonging to the ‘ancestral’ class of invertebrate defensins were cloned and sequenced. The deduced amino acid sequences contain the characteristic six cysteines of this class of defensins and reveal precursors of 60 or 61 amino acid residues. The mature peptides consist of 37 amino acid residues, showing up to 70% identities with tick and scorpion defensins. In C. salei, defensin mRNA was found to be constitutively expressed in hemocytes, ovaries, subesophageal nerve mass, hepatopancreas, and muscle tissue. This is the first report presenting and comparing antimicrobial peptides belonging to the family of defensins from spiders.     

Biology of the CAPA peptides in insects

CAPA peptides have been isolated from a broad range of insect species as well as an arachnid, and can be grouped into the periviscerokinin and pyrokinin peptide families. In insects, CAPA peptides are the characteristic and most abundant neuropeptides in the abdominal neurohemal system. In many species, CAPA peptides exert potent myotropic effects on different muscles such as the heart. In others, including blood-sucking insects able to transmit serious diseases, CAPA peptides have strong diuretic or anti-diuretic effects and thus are potentially of medical importance. CAPA peptides undergo cell-type-specific sorting and packaging, and are the first insect neuropeptides shown to be differentially processed. In this review, we discuss the current knowledge on the structure, distribution, receptors and physiological actions of the CAPA peptides. Received 28 April 2006; received after revision 5 June 2006; accepted 4 July 2006     

Regulation of sodium and body fluid homeostasis during development: Implications for the pathogenesis of hypertension

The spontaneously hypertensive rat (SHR) is an important animal model of human essential hypertension. During the first month of life, increased retention of sodium is present in the SHR which appears to be mediated by the renin-angiotensin system. The present review will discuss the role that increased activity of the renin-angiotensin system plays in sodium/body fluid regulation during early development. It is hypothesized that disordered regulation of sodium/body fluid homeostasis during this stage leads to pathological cardiovascular regulation in adulthood. Through an understanding of the relationship between sodium/body fluid balance in the young and cardiovascular function in the adult insights may be gained into both the pathological state of hypertension and the critical role played by early development in shaping homeostatic mechanisms in adulthood.     

Sterol metabolism in insects and biosynthesis of ecdysone in the silkworm

Cellular and Molecular Life Sciences -     

Regulation of sodium and body fluid homeostasis during development: implications for the pathogenesis of hypertension.

The spontaneously hypertensive rat (SHR) is an important animal model of human essential hypertension. During the first month of life, increased retention of sodium is present in the SHR which appears to be mediated by the renin-angiotensin system. The present review will discuss the role that increased activity of the renin-angiotensin system plays in sodium/body fluid regulation during early development. It is hypothesized that disordered regulation of sodium/body fluid homeostasis during this stage leads to pathological cardiovascular regulation in adulthood. Through an understanding of the relationship between sodium/body fluid balance in the young and cardiovascular function in the adult insights may be gained into both the pathological state of hypertension and the critical role played by early development in shaping homeostatic mechanisms in adulthood.     

Relaxin: a pregnancy hormone as central player of body fluid and circulation homeostasis

The peptide relaxin has long been regarded as an important hormone of pregnancy, contributing to changes in connective tissue composition as well as to regulation of implantation, myometrial activity and labor. On the other hand, the astonishing pleiotropy of this hormone escaped scientific awareness. This review focuses on new facets of relaxin, including its antifibrotic effects, its role in the control of pituitary hormone release, its vasodilator and pro-angiogenic properties and its versatile myocardial actions. Recent progress in understanding relaxin's receptor and signaling mechanisms is also highlighted. The peptide will be characterized as potential regulator of body fluid and circulation homeostasis.     

Neurosecretory products diversity in the pars intercerebralis of insects

Summary The pars intercerebralis of insect brain, which has numerous physiological functions, contains more neurosecretory cell types than previously thought. There are 2 distinct types among the A cells. In addition to these cells, there are azocarminophilic cells, the C(r) cells, which are not apparent when using classical staining methods.     

About the photostimulation of ATP production in the integument of insects

Summary The photostimulation of ATP production in the integument ofPieris brassicae has been reexamined, using 2 different methods for ATP estimation. As could be demonstrated with the luciferin-luciferase assay, the so-called photostimulation is an artefact which is due to inappropriate utilization of the Boehringer kit assay.     

Formation of enantiomeric sesquiterpenes in the secretions of scale insects

Summary The volatile oil present in the secretion of a scale insect,Ceroplastes ceriferus Anderson (fam. Coccidae), has been found to consist of a number of sesquiterpenes which are enantiomeric with respect to those fromC. rubens Maskell, which infests the same host tree. The present investigation strongly suggests that each insect possesses a specific set of C-C cyclases for the sesquiterpenoids.Acknowledgments. The authors would like to express their thanks to Dr Y. Asakawa (Tokushima Bunri Univ.) for providingC. ceriferus and to Prof. S. Takagi (Hokkaido Univ.) for the identification of it.     

The effect of some neurohormones on the heart rate of spiders

Résumé Les auteurs ont étudié l'effet de l'adrénaline et de l'acétylocholine sur le rythme du cur chez l'araignéeTegenaria atrica C. L. Koch. L'enregistrement s'est fait au moyen de l'électroencephalographe. L'injection de l'adrénaline provoquait l'accélération du rythme du cur, l'acétylocholine — son ralentissement.