Effect of diabetes on the enzymes of the cholinergic system of the rat brain

Summary Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activities were determined in several brain regions of normal and streptozotocin-induced diabetic rats. The diabetic rats exhibited significant increase in ChAT activity (p<0.05) in all brain regions studied except for the cortex and the midbrain. Meanwhile, the diabetes condition was associated with significant increase (p<0.05) in AChE activity of the bulbus olfactorius, medulla oblongata and cerebellum. These data suggest that uncontrolled diabetes is associated with significant alterations in the brain cholinergic systems.To whom requests of reprints should be addressed.This work was supported by grants from the National Aeronautics and Space Administration (NSG 2183 and NAG-2-411), a grant from the National Institutes of Health (NIH Grant RR0811) and a grant from the Division of Research Resources, National Institutes of Health (NIH Grant RR03020).     

Effects of sympathetic stimulation on ventricular refractory periods in cats with acute coronary artery ligation

Summary Ventricular refractory periods shorten in the ischemic area following acute coronary artery ligation. Subsequent bilateral sympathetic nerve stimulation reduces disparity in refractory periods across normal, border (peri-ischemic) and ischemic areas.This work was supported by NIH Research Grants HL 19044 and HL 21735, NIH Biomedical Research Support Grant DRR No. S07-05363 and a Grant-in-Aid from the American Heart Association, Florida Affiliate, Broward County Chapter. Dr Gaide is the recipient of NIH New Investigator Research Award HL 27680.     

Studies on the murine L-4946 ascitic leukemia in Swiss albino mice

Zusammenfassung Virologische Untersuchungen einer Mäuseleukämie, die sich durch eine «subzelluläre onkogene Komponente» übertragen lässt.

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This work was supported in part by the Developmental Physiology Training Grant No. NIH T1-HD0054; NIH Training Grant No. 1 T01 AMO-5680-01 DM; General Research Support Grant No. 623; and aided by a grant from the National Foundation — March of Dimes. This research was conducted in facilities accredited by the American Association for Accreditation of Laboratory Animal Care.     

Muscle hexose monophosphate shunt activity following exercise

Summary 1 day following prolonged treadmill walking untrained rats showed significant elevations in hexose monophosphate shunt reducing capacity in plantaris muscle. The increases were associated with accumulations of nuclei in the muscle interstitium, suggesting damage to the connective tissue element of the muscle.This work was supported by NIH Grant AM18123.     

Depletion of synaptic vesicles at the frog (Rana pipiens) neuromuscular junctions by tetraphenylboron

Summary At the frog neuromuscular junction tetraphenylboron produced a decrease in miniature endplate potential amplitude, accompanied by a decrease in the number but not the size of synaptic vesicles.This work was supported by NIH Grants Nos NS-07740 and NS-05707 to R. L. P. and was done during the tenure of a Research Fellowship of Muscular Dystrophy Associations of America, a Wellcome Research Travel Grant and a grant from the Carnegie Trust for the Universities of Scotland to I. G. M. The assistance of Dr.R. M. Schnitzler, W. G. Boldosser andP. M. Spannbauer is gratefully acknowledged.     

Insensitivity of the ferritin iron core to heat treatment

Summary To test whether the reactivity of ferritin iron is affected by the heat treatment used in ferritin isolation, we prepared ferritin from the same horse spleen with or without heating. Both samples exhibited similar reactivity upon reduction or chelation of iron.Acknowledgments. We are indebted to George Rossman who brought this problem to our attention. Work was supported in part by NIH Grant HL20141 and by the Petroleum Research Fund.     

Preliminary evidence that a dopamine receptor antagonist blocks the prolactin-inhibitory effects of melatonin in anosmic male rats

Summary Previous studies have shown that daily afternoon injections of melatonin in anosmic male rats result in depressed accessory sex organ weights and serum prolactin levels. The present data indicate that the prolactin-inhibitory effect of melatonin may be mediated via the dopaminergic system.This work was supported by NIH Biomedical Research Support Grant No. 3150-80.     

Altered brain cholinergic enzymes activity in the genetically obese rat

Summary Genetically obese male Zucker rats (fa/fa) and their lean littermates (Fa/-) were used in this experiment. Fourteen-week-old obese and lean littermates were sacrificed and choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) enzymes were assayed in specific brain regions. The assays of these enzymes indicate that obese animals and a significantly lower ChAT activity in the cerebellum, pons, and cerebral cortex and a significant increase in ChAT activity in the thalamus and hypothalamus. Meanwhile, the cerebral cortex, cerebellum, midbrain, thalamus and hypothalamus of the obese animals showed significantly higher AChE activity than their lean littermates. It was concluded from this study that obesity may be associated with changes in the enzymes of the brain cholinergic system.This work was supported by a grant from the National Aeronautics and Space Administration (NAG 2-411), a grant from the National Institutes of Health (NIH RR 0811), and a grant from the Division of Research Resources, National Institutes of Health (NIH Grant RR 03020).     

Functional consequences of treating turkey liver fructose-1,6-bisphosphatase with penicillin G

Summary Treatment of turkey liver fructose-1,6-bisphosphatase with penicillin G progressively inactivated the enzyme and desensitized the enzyme toward high substrate inhibition. The treatment also led to reduced sensitivity to AMP inhibition and the loss of cooperative interaction among AMP-binding sites. These altered properties were not reversed by dialysis, but were prevented when treatment with penicillin G was performed in the presence of substrate.This work was in part supported by grant RR-8006 from the General Research Branch, Division of Research Resources, NIH (USA) and in part by Faculty Research Grant from Southern School of Pharmacy, Mercer University, Atlanta (Georgia, USA).     

The influence of somatostatin on drug-induced prolactin release in the monkey

Summary The infusion of linear somatostatin did not block prolactin release induced by either perphenazine, TRH or serotonin. Somatostatin infusion, however, potentiated prolactin release induced by perphenazine and TRH but not that induced by serotonin.Supported in part by NIH General Research Support Grant No. RR5384 to Wayne State University School of Medicine and by NIH Research Grant No. HDO7722.The authors wish to express their appreciation to Mrs.Cynthia Van De Walle for her outstanding technical assistance in the performance of the prolactin RIA and the statistical analyses. We also appreciate receiving linear somatostatin from Dr.R. Makineni, Bachem Inc., Marina Del Ray, California, USA and from Dr.N. H. Grant, Wyeth Laboratories, Philadelphia, Pa. USA. We would like to thank Abbott Laboratories, North Chicago, Ill. USA for the gift of TRH and the Schering Corp., Bloomfield, N.J. USA for the gift of perphenazine.     

A simple method for the preparation of antibodies to the mitochondrial biotin-dependent carboxylases

Summary Heterologous antiserum to the 3 biotin-dependent carboxylases was prepared by selective removal of these enzymes from human liver on an avidin-sepharose column. A carboxylase-avidin-sepharose matrix was used as an antigen to produce anti-carboxylase antibodies. The resultant antisera can be used to purifiy the specific carboxylases, to prepare monoclonal antibodies to these enzymes or to study inherited carboxylase deficiencies and biotin-dependent intermediary metabolism.The authors thank Dr Emmanuel Shapira for his helpful suggestions and Patricia Tuck for her technical assistance. This work was supported by NIH research grants AM25675 and AM26127. Barry Wolf is a recipient of an NIH Research Career Development Award (AM00677) and is aided by a Basil O'Connor Starter Research Grant from the National Foundation—March of Dimes (5–263). This is paper No. 137 from the Department of Human Genetics — Medical College of Virginia.     

Inhibition of liver fructose 1,6-bisphosphatase activity by Zn2+: Reversal by imidazole pyruvate

Summary Imidazole pyruvate was found to be a very potent natural chelating agent in reversing the inhibition of liver fructose 1,6-bisphosphatase activity by Zn²⁺. This metabolite may play a physiological role in gluconeogenesis.This work was supported by grant RR-8006 from the General Research Branch, Division of Research Resources, NIH, USA.     

Liver esterase abnormalities in hereditary neurological diseases of mice

Zusammenfassung Alle von uns in Mäusen untersuchten vererblichen neurologischen Erkrankungen stellen entweder primäre oder sekundäre gesamtkörperliche Prozesse dar. Verschiedene allelische Substitutionen produzieren spezifische Leber-Esterase-Isozym-Defekte.

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This work was supported in part by NIH research grant No. NB 06448 from the National Institute of Neurological Diseases nad Stroke, a grant from the National Foundation for Neuromuscular Diseases, Inc., a grant from the Health Research Fund, United Fund of Schenectedy County, Inc., and an allocation from NIH General Research Support Grant No. RR 05545 from the Division of Research Resources to The Jackson Laboratory.

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The principles of laboratory animal care as promulgated by the National Society for Medical Research are observed in this Laboratory.     

Microinjection of synthetic protein kinase inhibitor into single barnacle muscle fibers before and after cyclic AMP

Summary Single muscle fibers from the barnacleBalanus nubilus have been used as a preparation to see if a synthetic 20-residue PKI (5-24)-peptide is able to block or reverse the stimulatory response of the ouabain-insensitive Na efflux to injected cAMP. The results obtained show that this peptide behaves as a powerful inhibitor of the cAMP-mediated response and is also able to partially reverse the sustained stimulation of the Na efflux observed in ouabain-poisoned fibers following the injection of subunit A of cholera toxin.Warmest thanks to Prof. E. H. Fischer and Kurt Diltz for a sample of sPK1. This work received support from NSF, the Graduate School Research Committee and from NIH through a General Research Support Grant to the University of Wisconsin Medical School.     

Fine structure of modiffied phtoreceptor cells in the pineal of the gobyClevelandia ios (Pisces: Gobiidae)

Summary Photoreceptor cells with a system of long, thi cytoplasmic processes (50–80 nm thick), which amy represent a modification of the outer segment saccules, are described in the pineal of the goby,Clevelandia ios.The author wishes to thank Mr Larry Allen, who helped collect the specmens, and Mr Kyle Kikuchi, who was instrucmental in the preliminary studies.Partial support by Biomedical Research Support Grant (NIH) No. 447-12-000 from the Stritch School of Medicine is gratefully acknowledged.     

Circadian variation of serum testosterone in the adult male rat with a late morning acrophase

Summary Serum testosterone concentrations were measured in adult male Sprague-Dawley rats. A significant circadian testosterone rhythm (p<0.01) was found with peak values at 10.00 and 13.00 h.Supported in part by NIH, NCI Grant No. CA 15062 and NIH, NIAMDD Grant No. 5 RO1 AM11376.The authors would like to acknowledge the excellent technical assistance of Ms.Kris Strom.     

Peptide interactions with taste receptors: Overlap in taste receptor specificity

Summary Two hitherto unrelated areas of taste appear to provide an important insight into a class of taste receptor sites. A region of the sweet protein monellin is similar to a savory tasting beef octapeptide, and this peptide region could represent an overlap in the specificity of binding to a common peptide taste receptor site. Such an overlap in binding specificity explains the low but significant level of sweetness observed with savory tasting stimuli.The work from this laboratory was supported by NIH Research Grant No. NS-15740 from NINCDS and by the Veterans Administration.     

A simple method for counting nuclei in the preimplantation mouse embryo

Summary An easy and rapid method of counting the number of cells in the preimplantation mouse embryo is described. The procedure increases the speed with which large numbers of embryos can be processed using a simple squash technique. Cell numbers are determined by exposing the embryos to the fluorescent DNA-binding dye, Hoechst 33258, removing the zona pellucida and simply squashing the embryo and counting the number of fluorescent nuclei. An increase in fluorescent intensity and maintenance of nuclear conformation of the squashed preparations are greatly improved by the use of the non-ionic detergent Triton X-100. Viability of dye-treated fertilized one-cell and blastocyst stage embryos is maintained at least up to day 13 of pregnancy following transfer of the embryos to the uteri of pseudopregnant recipients. Additional uses for this staining technique are discussed.Acknowledgment. Financial support was provided by NIH Grant HDD-06210 (KME) and by Basil O'Connor Starter Research Grant No. 5-379 from the March of Dimes Birth Defects Foundation (VEP). We thank Steven Halpern for help with the photography and Jon Flax for expert technical assistance.     

Fever in the monkey produced by the direct action of pyrogen on the hypothalamus

Zusammenfassung Eine dosisabhängige Steigerung der Körpertemperatur wurde erzielt, wenn Pyrogen-Substanzen aus verschiedenen gram-negativen Bakterienstämmen stereotaktisch in den Hypothalamus nicht narkotisierter Affen injiziert wurden.

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Supported in part by USA Office of Naval Research Contract No. N00014-67-A-0026-0003 and National Science Foundation Grant No. GB 7906. We are indebted toP. Curzon for his valuable technical assistance, and to Dr.R. L. Somerville for preparing the pyrogens.

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Post-Doctoral Fellow supported by NIH Health Sciences Advancement Award No. PHS 5-S04-FR-0615.

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NIH Pre-Doctoral Fellow in Neurobiology.     

Morphological and functional changes in the distal hypothalamo-neurohypophysial system of the grass frog (Rana pipiens) after transection of the proximal neurohypophysis

Zusammenfassung Nach Durchtrennung der proximalen Neurohypophyse wird im distalen Stumpf eine gegenüber Kontrolltieren erhöhte Menge paraldehyd-fuchsinpositiver Substanz gefunden, die im Elektronenmikroskop einwandfrei als Neurosekret identifiziert werden konnte. Die im Tierversuch ermittelte erhöhte, blutdrucksteigernde Aktivität des distalen Teils der Neurohypophyse spricht für eine lokale Synthese des Neurosekrets.

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Supported by NIH Grant No. NB 06641 and the Space Sciences Research Center of the University of Missouri.