Flavonoid profiles of certain species ofRhynchosia of the family Leguminosae (Fabaceae)

Summary A survey of seventy naturally occurring populations ofRhynchosia representing seven species of different subgenera revealed the occurrence of C-glycosides, O-glycosides, prenylated flavonoids and aglycones.Rhynchosia albiflora (R. cyanosperma) differs in gross morphological features and seed coat color and in its flavonoid composition from the other representative species ofRhynchosia.Acknowledgments. P. Ramachandraiah is grateful to U.G.C., New Delhi, for financial assistance.     

A lens-like specialization for photic input in the pineal window of an Indian catfish,Heteropneustes fossilis

Summary An unusual lens-like structure is reported in the pineal window of the Indian nocturnal catfishHeteropneustes fossilis. This is the first report of its kind for the pineal window of fishes. This structure, coupled with a pineal fossa and a pineal window, forms a specialization that apparently serves to concentrate the photic input to the intracranially situated pineal organ. This structure may play a significant role in the photoneuroendocrine function of the photosensitive pineal under conditions of low light intensity, controlling the fish's circadian rhythmic activities.The work was financially supported by CSIR, New Delhi (sanction No. 38(693)/88/EMR-II dated May, 1988) which is thankfully acknowledged.     

Torus shaped bands at the 2R telomere region and at the region 68 of the salivary gland chromosomes ofDrosophila auraria

Summary The telomere of the 2R arm of the salivary gland chromosomes ofD. auraria exhibits a definite toroidal structure in routine squashed preparations, stained either by propionic orcein-carmine or by fluorescent dyes. There is evidence that a band (or bands) of region 68 (possibly homologous to that ofD. melanogaster) of the 3L chromosome arm also exhibits a toroidal structure. These toroids are associated with heterochromatin, but it is not certain that they are themselves heterochromatic.Acknowledgments. This work was supported by a grant from Volkswagenwerk-Stiftung to C.D.K. The outstanding technical assistance of Ms G. Karamanlidis is acknowledged.     

The effect of heat on rat pineal hydroxyindole-O-methyl transferase activity

Summary Exposure of adult male rats to continuously elevated temperature of 32–34°C caused a significant decrease of HIOMT activity involved in the specific metabolic process of production of melatonin, considered an active pineal hormone. The effect was already evident after 24 h exposure and increased further during the next 48 h. The results obtained substantiate previous data that the pineal gland may be involved in the system regulating adaptation to extreme temperature changes.Acknowledgment. The authors are indebted to MissUte Schmidt for her excellent technical assistance.     

A potent actomyosin ATPase activator from the Okinawan marine spongeAgelas cf.nemoechinata

Summary A bromine-containing alkaloid, oxysceptrin, has been isolated as a potent actomyosin ATPase activator from the Okinawan marine spongeAgelas cf.nemoechinata, and the structure elucidated to be1 on the basis of the 2D NMR spectral data.Acknowledgments. We thank Mr Z. Nagahama for his help in sponge collecting and Ms M. Takamatsu for her technical assistance.     

Visual input to rat pineal

Summary Electrophysiological recordings from freely behaving rats, previously implanted stereotaxically with permanent electrodes in the pineal, ventromedial hypothalamus, caudate nucleus, lateral geniculate body and medial geniculate body were obtained. The pineal photic responses revealed 5 sequential components. Injection of a neuronal blocker at the level of the superior cervical ganglion did not alter the earlier photic responses, but did eliminate the late components (N₂–P₃) for 60–90 min after the injection. All of the other responses were unchanged during the experiment. The present experiments demonstrated that photic input travels to the pineal through two pathways.The author is grateful to Dr C.M. Prashad and Ms. Marjorie Brown for technical assistance. Supported in part by grant NS 16596.     

The effect of daily evening isoproterenol administration on reproductive organ growth in male rats treated neonatally with testosterone propionate

Summary Daily evening injections of isoproterenol extended the period of high pineal N-acetyltransferase activity and retarded the growth of testes, seminal vesicles and prostate in rats treated neonatally with testosterone propionate.The authors are grateful to Mrs Marie Svobodová for her skillful technical assistance.     

Communicating junctions between pillar cells in the gills of the atlantic hagfish,Myxine glutinosa

Summary In the respiratory lamellae of the gills of the atlantic hagfish,Myxine glutinosa, pillar cells are coupled by communicating junctions. It is suggested that these cells behave like a functional syncytium.Supported by the DFG, SFB 146. The authors are indebted to Drs F. Walvig and H. Stolte for kindly providing the hagfish. The expert technical assistance of G. Voss-Wermbter, Dipl.-Ing., and H. Heidrich is gratefully acknowledged.     

In vitro metabolism of the trichothecene 4-monoacetoxyscirpenol by fungus- and non-fungus-feeding insects

Summary The metabolism of the trichothecene 4-monoacetoxyscirpenol by intact gut tissue was determined in the fungus-feeding Nitidulid,Carpophilus hemipterus (L.) and the non-fungus-feeding caterpillars, the fall armyworm,Spodoptera frugiperda (J. E. Smith) and the corn earworm,Heliothis zea (Boddie). The primary metabolite was the hydrolysis product scirpentriol. The amount of metabolism by theC. hemipterus larvae was ca 10 times that of the caterpillars on a per mg protein basis, suggesting metabolic adaptation for feeding on fungi that may contain mycotoxins.Acknowledgment. The authors wish to thank S. Taylor for technical assistance.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

The concentration of ammonia in the excreta of sixth instar larvae ofLamida moncusalis Walker (Pyralidae: Lepidoptera) during development

Summary The concentration of ammonia in the fresh and dry excreta ofLamida moncusalis Walker was determined. It was found that a large quantity of ammonia was lost from the excreta on drying. Ammonia is one of the major excretory products of the larva.5 September 1986Acknowledgment. We thank the State Committee on Science, Technology and Environment, Kerala, for the financial assistance.     

Effect of testosterone on the hypothalamic-pituitary-gonadal axis of pinealectomized and pineal-intact male rats

Summary Previous studies indicate that steroid hormones alter pineal biochemistry, and it has been suggested that at least part of the negative feedback effect of steroid hormones on pituitary gonadotropin release may be mediated by the pineal gland. In this study, pinealectomy did not alter the inhibitory effect of testosterone on neuroendocrine-gonadal activity in the male rat, suggesting that the pineal gland does not mediate the response of the rat hypothalamic-pituitary axis to testosterone.We wish to thank Susan H. Losee, Brigitte G. Mann and John Georgeson for excellent technical assistance. This investigation was supported by NSF grant SER 77-03836 and a grant from the University of Wisconsin-Parkside Committee on Research to E.P.W. and by NIH grant HD-09885 and NSF grant PCM 76-09955 to F.W.T.     

An extremely cadmium-sensitive strain ofChlorella

Summary Growth of 14 strains from fiveChlorella species is rather insensitive towards cadmium. One strain (211-1a) ofC. saccharophila, however, was found to have a sensitivity towards this toxic heavy metal about 100 times higher than that of the other strains ofC. saccharophila.Acknowledgment. For excellent technical assistance I am indebted to Mrs U. Knoch and Mrs E. Weitemeyer.     

Observations on the toxicity and metabolic relationships of polygodial,the chemical defense of the nudibranchDendrodoris limbata

Summary Polygodial (1), the defense metabolite stored in the skin of the nudibranchDendrodoris limbata, is toxic for the mollusc itself when injected into the hepatopancreas. Biosynthetic experiments using labeled mevalonic acid were devised to investigate a possible metabolic relationship between1 and the mixture of sesquiterpenoidic esters2, stored in the hepatopancreas. The results suggest that1 and2 are biosynthesized by independent pathways.Thanks are due to G. Villani for supplyingDendrodoris limbata and to A. Trabucco for technical assistance.     

Central neural control of pineal melatonin synthesis in rat

Summary To investigate a possible central neural influence on nocturnal pineal metabolic activity, frontal transsections of the stria medullaris thalami were conducted. Enzymes involved in melatonin synthesis, i.e. N-acetyltransferase and hydroxyindole-O-methyl-transferase, exhibited reduced activities in operated animals when compared to controls. These results indicate a modulatory role of central structures on noctural pineal indole metabolism.This study was supported by the Deutsche Forschungsgemeischaft and the Stifung Volkswagenwerk. The technical assistance provided by M. Henschel, I. v. Graevenitz and G. Schlich is gratefuly acknowledged.     

Effect of light at night on the pineal rhythm in N-acetyltransferase activity in the Syrian hamsterMesocricetus auratus

Summary Pineal N-acetyltransferase activity in the male Syrian hamster exhibited a daily rhythm; the maximal night-time value was 3.5-fold higher than the day-time value. When hamsters were exposed to light at night N-acetyltransferase declined within 30 min to 1/5 of its former activity. These results indicate that in the Syrian hamster the pineal melatonin rhythm may be regulated at least partly via changes in N-acetyltransferase activity.The authors are grateful to Mrs Marie Svobodová for her skillful technical assistance.     

Ecdysis inhibition inAcrolepiopsis assectella larvae by digitonin: antagonistic effects of cholesterol

Summary Digitonin has a toxic effect onAcrolepiopsis assectella, inhibiting development and molting of young larvae fed on a semi-synthetic diet. This effect depends on concentration. It does not occur when cholesterol is added to the diet.Acknowledgment. We thank Mme Annie Heinzmann for technical assistance.     

Influence of pinealectomy on serum estrogen and progesterone levels in blind-anosmic female rats

Summary Previous studies show that the suppression of gonadal function in blind-anosmic rats is dependent on the pineal gland. The present results demonstrate that in young female rats both the pineal gland and dual sensory deprivation have additional independent antigonaldal effects.This work was partially supported by state institutional funds and by NSF grant No. PCM 74-06276-276-A02. The radioimmunoassays of the steroids were carried out with the aid of the Radioimmunoassay Core which is supported by USPHS grant No. 1T30 HD-10202. We also thank Constance Stahl for typing assistance.     

Fitness traits associated with the red back phenotype in the migratory grasshopper,Melanoplus sanguinipes

Summary The dominantly inherited variant, red back, in the migratory grasshopper,Melanoplus sanguinipes, is rare in nature. The present study illustrates that is this probably due, in part, to the trait's association (either through pleiotropy of the red back gene,Pro and/or closely linked fitness loci) with lower egg hatchability, greater developmental time, greater mortality during later stages, and a greater tendency to have an extra instar.A part of an M.Sc. thesis of F. R. H. Hodson, University of Regina (1985).Financial assistance from the Natural Sciences and Engineering Research Council (A0485) is greatfully acknowledged. Address reprint requests to W.C.     

Identification of a new predaceous stink bug pheromone and its attractiveness to the eastern yellowjacket

Summary Males ofPodisus fretus (Hemiptera: Pentatomidae) release a long-range attractant pheromone containing linalool (49.0%), (E)-2-hexenal (34.5%), benzyl alcohol (12.0%), nerolidol (2.0%),-terpineol (1.1%), and traces of several other compounds. The eastern yellowjacket,Vespula maculifrons (Hymenoptera: Vespidae), is attracted to artificial pheromones forP. fretus and for the sympatric species,Podisus maculiventris.The authors thank Mr T.J. Henry of the USDA Systematic Entomology Laboratory and Dr J.E. McPherson, Southern Illinois University, for examining the pentatomid species and Dr A.S. Menke, USDA-SEL, for determining the yellowjacket species. We also thank S. Wilzer for technical assistance. Mention of a company name does not imply endorsement by the US Department of Agriculture.     

Disruption of circadian rhythm of tissue respiration inChanna striatus by Metasystox®

Summary Oxygen consumption of gill, brain and muscle tissues ofChanna striatus exhibits a clearcut circadian rhythm with a maximum uptake at 18.00 h. Metasystox exposure decreased the oxygen consumption of all tissues. Maximum reduction is noted in gill followed by brain and muscle. The peak period of oxygen consumption is also eliminated in the pesticide-treated fish.Acknowledgments. Prof. G. Sundara Rajulu is thanked for suggestions and UGC for financial assistance.