Uridine uptake and RNA synthesis in the brain of torpid and awakened ground squirrels.

1. Uptake of [3H]uridine into the nucleotide precursor pool after intraventricular injection occurs with the same intensity in the brain of torpid and normothermic awakened ground squirrels. This indicates that the membrane uridine transporters and uridine kinases operate in the hibernator's brain in a hypothermia-tolerant way. 2. Utilization of the [3H]uridine pool for synthesis of the rapidly labelled RNA in the brain of torpid ground squirrels falls more than eight times against RNA labelling in the brain of the active animals between bouts of hibernation. 3. Two hours from the beginning of the artificially provoked awakening, RNA uridine incorporation in the brain of ground squirrels has risen 6.5 times. 4. Drastic changes in [3H]uridine RNA labelling under the stable uridine uptake exclude the precursors and energy supply as the main factors determining changes in intensity of the brain RNA synthesis in the different stages of hibernation.     

Differences in the ribosome state of nerve cells detectable by acridine orange fluorochrome staining

Acridine orange (AO) binding with ribosomal RNA in the cytoplasm of nerve cells depends on the animal functional state to differ in active and hibernating ground squirrels. These differences are expressed as changes in the ratio of red and green AO luminescence intensities. The transition of squirrels from the activity to hibernation provokes a five-fold fall in the red luminescence, while the green one shifts no more than by 10%, thus indicating the change in AO interaction with one-helical regions of rRNA only. The red luminescence decreases simultaneously with the rise of monoribosomes portion and dissociation of polysomes, but does not depend on RNA concentration in the cytoplasm. The dependence of AO binding on protein-RNA interaction in the one-helical regions and its relation to the capacity of ribosomes of protein synthesis are discussed.     

Experimental cytophotometric investigation of the effects of denervation on catecholamines and acetylcholinesterase in neurons of the intramural plexus of the cat urinary bladder

Catecholamines and acetylcholinesterase were determined by histochemical methods in neurons of the intramural plexus of the cat urinary bladder. The ganglia of this plexus were found to differ in the number of neurons they contained (from five to 150 cells). Adrenergic, cholinergic, and mixed ganglia exist. Division of the pelvic nerves increased the catecholamine content in adrenergic neurons and fibers and reduced acetylcholinesterase activity. Division of the hypogastric nerves has no effect on the catecholamine level and acetylcholinesterase activity in ganglia of the intramural plexus of the urinary bladder.Institute of Physiology, Academy of Sciences of the Belorussian SSR, Minsk. Translated from Neirofiziologiya, Vol. 17, No. 2, pp. 263–270, March–April, 1985.