Litorin and litorin-albumin conjugate as effective regulators of body temperature in rats.

Intraperitoneal injection of the bombesin-like peptide litorin (0.5 ml of a 10(-5) M solution) led to a short-lived decrease in the body temperature (maximum of 0.9 degrees C) of laboratory rats.

[Intake of water and sodium chloride solution by the rats after central administration of litorin and immunization with litorin-bovine serum albumin conjugate].

Central injection of litorin suppressed water and sodium chloride solution intake, and also decreased the preference of saline of unrestrained rats during 1 hour test. Active immunization of animals with litorin-bovine serum albumin conjugate led to the augmentation of their daily saline preference. Immunized rats increased also avidity to salt after deprivation, though the consumption volume of liquids decreased.

[Specific changes in the sodium chloride intake and activity of the taste receptor apparatus of rats administered the peptide litorin and its albumin conjugate].

The role of bombesin-like peptide litorin in control of salt consumption was studied in rats. The influence of exogenous injection and binding of the endogenous litorin in the organism on the consumption of sodium chloride and sucrose solutions was analyzed in deprived rats in the process of 15-min. testing.

[Pharmaco-histochemical study of monoamine-containing cells in the taste buds as affected by capsaicin-induced substance P deficiency].

A clearly positive correlation between the level of substance P (SP) in the taste nerves and cellular serotonin content in the taste buds has been established using fluorescent-histochemical technique. In chronic SP deficiency caused by capsaicin, cellular serotonin content was considerably decreased due to the disturbances in its synthesis and uptake. The injection of exogenous SP resulted in the recovery of the initial serotonin level.

[Histoarchitectonics of the cholinergic innervation of the frog tongue].

Acetylcholinesterase (AChE) activity was studied in dorsal tongue surface structures and in both tongue nerves (hypoglossal and glossopharyngeal) of frogs (Rana temporaria). AChE was found in nerve fibers of fungiform and filiform papillae, blood vessels, glandular ducts of tongue mucosa, both nerve fibers and also in the bodies of cholinergic neurons in subepithelial connective tissue and along the glossopharyngeal nerve. Their parasympathetic origin was suggested.

[Effect of taste deafferentation on the preference for solutions of saccharose, saccharin and salt in rats].

The preference of sucrose, saccharin and salt solutions to water was analyzed during 5 days in rats with bilateral section of the lingual nerve comprising the taste nerve--chorda tympani. In the process of the analysis of daily consumption and choice of solutions, different types of behavioural reactions were found: stable preference and change of preference. The number of rats preferring NaCl was greater among the animals with sectioned lingual nerve than among sham-operated control rats and rats with ligated ducts of submaxillary and sublingual salivary glands.

[Activating effect of cholecystokinin-pancreozymin on the taste-receptor system of the rat].

The effect of the intraperitoneal injection of 10(-5) M cholecystokinin-pancreozimin solution on the taste total impulse activity of the rat chorda tympani was studied. The taste responses to sodium chloride and sucrose increased within 5 min and responses to quinine increased within 30 sec after the peptide injection. Responses to citric acid solution did not augment significantly.

[Effect of substance P on the monoamine-containing cells of the taste buds].

The effect of substance P (SP) on monoamine-containing cells of the frog taste buds was studied by fluorescent microscopy. Intraperitoneal injection of SP resulted in a gradual increase of cell serotonin content. In monoamine deficiency caused by previous injection of rausedyl, SP favoured the recovery of the serotonin level to initial.

[Effect of antibodies against tubulin on the activity of taste receptors].

Electrophysiological studies were carried out to investigate the effect of monospecific tubulin antibodies on the activity of the receptor gustatory apparatus of Rana temporaria under adequate stimulation of receptors with NaCl and glucose solutions and water. There was a significant decrease in receptor responses to NaCl and water stimulation after administration of antibodies. Glucose responses were less prone to the effect of antibodies.

[Development of the chemo- and mechanoreceptors of the tongue in mature-born animals (scanning electron microscopy)].

Scanning electron microscopy was used to study developmental changes in the chemo- and mechanosensory apparatus of the tongue in guinea-pigs, goats and sheep during the 1st to the 10th postnatal week. The maturation of the chemosensitive postnatal formation of the mechanosensitive papillae was shown.

[Electrical response of frog lingual epithelium to stimulation of the gustatory nerve].

Electrical stimulation of the gustatory nerve evoked a positive electrical response of the outer surface of the tongue (relative to its inner layers). The amplitude and the rate of rise of the response grew and the latency fell with increased frequency of stimulation. The response originated in the superficial epithelial layer (30-60 micrometers) and was produced by a decrease of "resting potential" (negative-outside) of this layer.

[Significance of serotonin in the activity of the taste receptor apparatus of the frog Rana temporaria].

Studies have been made of the effect of exogeneous serotonin on responses of taste receptors recorded from the hypoglossal nerve during adequate stimulation. It was shown that serotonin evokes afferent discharge in this nerve and significantly increases responses of taste receptors. Stimulating effect of serotonin appears 15-20 min after its application and gradually develops reaching maximum within 60 min after injection.

[Effects of colchicine, cyclic nucleotides and biogenic amines on the chemoreceptor apparatus of the tongue].

Colchycine considerably decreased sensitivity of the Rana temporaria tongue's chemoreceptors to adequate stimulation. The effect is reversible and can be abolished by administration of drugs initiating setting of the cells' microtubular apparatus: 3',5'-cAMP, theophylline, adrenaline as well as by activation of the sympathetic system. The restoring effect of these agents is specific since 2',3'-cAMP, 5'-AMP, serotonin, inosine, acetylcholine and 3,'5'-cGMP prove ineffective in restoring the reactions after colchycine administration although they do alter the activity of the receptors in normal conditions.

[Recovery of colchicine-blocked chemoreceptor reactions of the frog tongue as affected by electrical stimulation of the sympathetic nervous system].

Under adequate stimulation of tongue chemoreceptors with feeds synchronous recording of the total afferent impulse activity of the glossal branches of Rana temporaria glossopharyngeal nerves was used to demonstrate the facilitation effect of electric stimulation of the I sympathetic ganglion on the receptor reactions in health and after treatment with colchicine provoking a considerable weakening of the reactions. The data are discussed in the light of the adaptation-trophic effect of the sympathetic system at the level of molecular-metabolic intracellular processes. No poisoning effect of alkaloid on the sympathetic fibers has been recorded.

[Possible role of sympathetic influences and cAMP in centrifugal inhibitory control of the gustatory receptor apparatus].

The electrophysiological analysis of the taste total impulse activity of the rat revealed the inhibitory influence of the gastric distention on the salt and sour taste responses to be decreased by cutting of the neck sympathetic nerve and prevented by the propranolol injection into the taste epithelium. Salt and sour taste responses were diminished by the injection of isoproterenol, cAMP, dibutyril--cAMP, and the inhibitors fo phosphodiesterase theophilline and paraverine; the activator of phosphodiesterase nicotine acid increased the taste responses. The finding suggest that the adrenergic transmitters and cAMP take part in the actualization of the inhibitory centrifugal influences.

[Morphofunctional characteristics of the accessory structures of the cat lingual receptors].

By means of scanning electron microscopy detailed topographic map of the cat tongue was made. It was demonstrated that besides three types of chemoreceptor formations, the dorsal surface of the cat tongue possess the same amount of additional mechanoreceptor structures. By means of registration of afferent impulses, from the lingual nerve fibres at their adequate stimulation, it was possible to determine functional role of some of them.

[Development of accessory structures of the mechano- and chemoreceptor apparatus of the tongue during rat ontogeny (scanning electron microscopy)].

The dynamics on the formation of different types of mechno- and chemosensitive papillae in the rat tongue has been studied during different periods of postnatal ontogenesis by means of scanning electron microsopy. Asynchronous maturation of these papillae has been demonstrated, they perform certain functions during the early postnatal ontogenesis and reach their functional maturity by the age of 3 weeks when animals go over from suckling to solid food.

[Topography of the auxiliary structures of chemo- and mechanoreceptor formations in the tongues of adult rats according to scanning microscope findings].

The surface of an adult rat tongue was investigated by scanning microscopy. Structural organization of the chemo- and mechanoreceptor formations of the tongue was described and their topographic chart was drawn on the basis of the experimental material. An attempt was made to explain the functional significance of these formations.