On the pathway of the rectosphincteric reflex

In several rat models, including those with circular and semicircular rectal aganglionosis, the rectosphincteric reflex was examined. The reflex was confirmed to be essentially an intramural one and its route is considered to run mainly in the longitudinal and partly in the oblique directions.     

Comparative distribution of vasoactive intestinal polypeptide (VIP), substance P and PHI in the enteric sphincters of the cat

In the feline gastrointestinal tract, the neuropeptides, substance P, VIP and PHI were investigated by specific radioimmunoassays and immunocytochemistry. The concentrations of all 3 peptides and the level of peptidergic innervation were significantly less in the anal sphincter than elsewhere, whereas no significant differences were seen between other sphincter and non-sphincter regions.     

Viscero-somatic reflexes following distension of urinary bladder in cats: Role of supraspinal neuraxis

Summary Viscero-somatic reflexes have been studied by recording monosynaptic reflexes following distension of the urinary bladder in intact, decerebrate and spinal animals. It was observed that the viscero-somatic responses following bladder distension are inhibitory in nature and this inhibition was highest in decerebrates and least in spinal animals. The site of viscero-somatic interaction probably lies in the bulbar area (supraspinal) and spinal cord.Acknowledgment. The work was carried out with the financial assistance of the Indian Council of Medical Research, Govt of India. We are thankful to A. T. Pradhan, Abott Laboratories (India) Pvt. Ltd. for a generous supply of Nembutal.     

Antiviral activity of coralloid root ofCycas revoluta extract against some viruses of tomato plant

Summary Crude coralloid root extract ofCycas revoluta showed significant antiviral activity against viruses of the tomato plant (PVX, PVY, TMV, TAV and TRSV) when applied 24 h before virus inoculation, or when mixed with different virus inocula before virus inocultion, in hypersensitive and systemic hosts. No such inhibition was observed when extract was applied 24 h after virus inoculation. TAV did not show any inhibitory response in a systemic host.Authors are thankful to Dr S. N. Gupta and Dr (Smt.) K. Shukla for their valuable guidance and providing laboratory facilities and U.G.C. for financial assistance.     

Cadmium-induced inhibition of brain monoamine oxidase in the freshwater catfish

Summary The freshwater catfishClarias batrachus (L.), exposed to 50 ppm of cadmium (Cd) chloride for a period of 135 days exhibited marked inhibition of brain monoamine oxidase (MAO) (p<0.001). The retarded gonadal growth observed in the present study suggests that Cd may be capable of creating imbalance in the aminergic activity of the hypothalamus, which modulates the secretion and release of gonadotropins.Acknowledgment. Financial assistance from the Council of Scientific and Industrial Research of India made this work possible.     

Antibacterial activity in the egg mass of a sea hare

Summary The eggs of a sea hare,Aplysia kurodai, contained antibacterial factors which probably play a role in the defense of eggs against bacterial infection. The active factors were composed of several heat-labile proteins, unrelated to lysozyme, and were produced in the albumen gland.     

Accumulation of3H-dopamine by synaptic vesicles from rat striatum in an impermeant medium

Summary The accumulation of³H-dopamine by synaptic vesicles from rat striatum was significantly stabilized in a membrane impermeant medium. The characteristics of dopamine accumulation by striatal vesicles were quite similar to those reported for dopamine accumulation by a whole brain vesicle preparation in the same medium, and were siginificantly different from the characteristics previously reported for vesicular accumulation of norepinephrine.Acknowledgments. This work was supported by grant NS 18752 (NIH) of the United States Public Health Service. Reprint requests to J. A. R.     

A rat mutant unable to synthesize vitamin C

Summary A colony of Wistar rats with a hereditary defect in L-ascorbic acid-synthesizing ability was established. This rat, like primates and guinea pigs, lacks L-gulonolactone oxidase (EC 1.1.3.8) which catalyzes the last step of L-ascorbic acid biosynthesis. When L-ascorbic acid was added to their drinking water, the rats grew almost normally and were fertile. These mutant rats should be useful not only for nutritional and parmacological studies on vitamin C but also for genetic studies on the lack of this enzyme.Acknowledgments. We are indebted to K. Katagiri, the previous director of Aburahi Laboratories, for his encouragement during the experiment. We are also grateful to H. Nishimura, Professor Emeritus of Kyoto University, and Y. Hasegawa of our laboratory for their helpful suggestions.