[The effect of vasotocin and mesotocin on the suprarenal gland of the frog Rana temporaria in vivo and in vitro]. / Vliianie vazototsina i mezototsina na suprarenalovuiu zhelezu liagushki Rana temporaria in vivo i in vitro.

Biochemical and morphometric analyses have been made of the effects of nonapeptide neurohormones, vasotocin and mesotocin, on the chromaffin tissue of the adrenal gland of the frog, both in vivo and in vitro experiments. It was shown that vasotocin exerts stimulating effect on the suprarenal gland whereas mesotocin inhibits the latter. In vitro experiments revealed that adrenalin may abolish the effect of nonapeptides on the suprarenal gland.

[The effect of vasotocin, mesotocin and adrenaline on the interrenal gland in the frog Rana temporaria under in-vitro conditions]. / Vliianie vazototsina, mezototsina i adrenalina na interrenalovuiu zhelezu liagushki Rana temporaria v usloviiakh in vitro.

Morphometric studies indicate that vasotocin increases the activity of the adrenal gland in frogs, whereas mesotocin and epinephrine do not essentially affect it. Combination of epinephrine with nonapeptides in cultural medium showed that the former may abolish the effect of vasotocin on the adrenal gland.

[The effect of injections of arginine vasotocin and mesotocin on the function of the interrenal gland in the frog Rana temporaria 2 months after the removal of the anterior lobe of the hypophysis]. / Vliianie in''ektsii arginin-vazototsina i mezototsina na sostoianie interrenalovoi zhelezy liagushki Rana temporaria spustia dva mesiatsa posle udaleniia perednei doli gipofiza.

Morphometric and biochemical studies have been made on the activity of interrenal gland in the frog Rana temporaria after removal of the anterior lobe of pituitary and injections of arginine vasotocin and mesotocin. It was demonstrated that the activity of this gland after the operation decreases increasing after arginine vasotocin injections.

[The reaction of the thyroid in the frog Rana temporaria to arginine-vasotocin administration]. / Reaktsiia shchitovidnoi zhelezy liagushki Rana temporaria na vvedenie arginin-vazototsina.

Using morphometric technique, it has been shown that single and especially three successive injections of a hypothalamic nonapeptide neurohormone, arginin-vasotocin (5.10(-9) M/kg of body weight) affect functional activity of the thyroid gland in sexually mature male frogs which had been subjected to hypophysectomy 10 or 60 days before neurohormonal treatment. These data presumably confirm a hypothesis about the direct para-adenohypophysial influence of the hypothalamic nonapeptide neurohormone on the peripheral endocrine glands, particularly, the thyroid one.

[The effect of dehydration on the functional activity of the interrenal gland in adenohypophysectomized Rana catesbeiana frogs. A preliminary report]. / Vliianie degidratatsii na funktsional'nuiu aktivnost' interrenalovoi zhelezy u adenogipofizéktomirovannykh liagushek Rana catesbeiana. Predvaritel'noe soobshchenie.

A significant increase of the content of corticosterone in the blood collected from intravenous cannula or by intracardiac punction has been detected using radioimmunoassay in non-operated and adenohypophysectomized frogs Rana catesbeiana subjected to dehydration in 6.2% mannitol solution during 24 hours. The osmolality of the blood plasma of these animals also increases although less significantly than the growth of plasma corticosterone content. There is a tendency to substantial increase of plasma arginine-vasotocin level prior to the growth of corticosterone level, already after 6 hours of dehydration. Based on the present results and literature data, it is suggested that in adenohypophysectomized frogs lacking endogenous ACTH just the increase of blood arginine-vasotocin level results in a substantial activation of corticosteroid-producing cells of the interrenal gland and in the growth of plasma content of corticosterone.

[The direct stimulating effect of arginine vasotocin on the functional activity of the interrenal gland in the frog Rana temporaria]. / Priamoe stimuliruiushchee vliianie arginin-vazototsina na funktsional'nuiu aktivnost' interrenalovoi zhelezy liagushki Rana temporaria.

Using radioimmunoassay it has been detected that both nonoperated and hypophysectomized, lacking endogenous ACTH, frogs injected one or three times with arginine vasotocin (5.10(-9) M/kg b. w.) show a statistically significant increase of plasma corticosterone level as compared with that in control animals and frogs injected with Ringer solution. The level of 11-hydroxycorticosteroids (fluorometric determination) in the interrenal gland decreases significantly only in animals three times injected with arginine vasotocin. It is assumed that arginine vasotocin produces a direct stimulatory effect on corticosteroid-producing cells of the frog interrenal gland.

[The effect of serotonin on the hypothalamic structures that participate in the regulation of the hypophyseal-adrenal cortex system]. / Vliianie serotonina na gipotalamicheskie struktury, uchastvuiushchie v reguliatsii gipofizarno-adrenokortikal'noi sistemy.

The activation of the 11-hydroxycorticosteroids secretion by 5-hydroxytryptophan was confirmed in intact rats as well as in those with isolated mediobasal hypothalamus. Deafferentation of the medial basal hypothalamus did not prevent an increase of corticoliberin and vasopressin content in the external median eminence after adrenalectomy and led to an opposite response after 5-hydroxytryptophan injection in these rats. The activation of the vasopressinergic cells and increase of portal vessels' lumen occurred under the 5-hydroxytryptophan effect, particularly in rats subjected to deafferentation combined with adrenalectomy.

[Morphofunctional research on the interrenal gland of the frog Rana temporaria following arginine vasotocin administration]. / Morfofunktsional'noe issledovanie interrenalovoi zhelezy liagushki Rana temporaria posle vvedeniia arginin-vazototsina.

Studies have been made of the effect of injections of hypothalamic nonapeptide neurohormone, arginine vasotocin, on functional condition of the interrenal gland in mature frogs. In unoperated, sham-operated and in animals 10 days after hypophysectomy, single and especially three subsequent injections of arginine vasotocin (5 x 10(-9) M per 1 kg of the body weight) result in evident activation of glandular cells of the interrenal gland which is manifested in the increase of the volume of their nuclei and cytoplasmic area, as well as in the dilatation of the blood vessels. Activation of the interrenal gland in hypophysectomized frogs, which lack endogenous ACTH, indicate the direct para-adenohypophyseal influences of nonapeptide hypothalamic hormones on the activity of glandular cells in the peripheral endocrine glands, in particular, the interrenal gland of the grass frog.

[Age-related dynamics of the response of the hypothalamo-hypophyseal neurosecretory system in rats to a change in corticoid levels of the blood]. / Vozrastnaia dinamika reaktsii gipotalamo-gipofizarnoi neirosekretornoi sistemy krys na izmenenie urovnia kortikoidov v krovi.

Hypothalamic vasopressin- and corticoliberinergic neurosecretory cells are able to change their activity after true or shame adrenalectomy in respect to the level of corticoids even in 10-day old rats. Vasopressin and corticoliberin accumulate in the nerve fiber terminals of the median eminence external zone a few days after surgery in young rats as opposed to the accumulation within 2-3 weeks usually observed in adults. The underdifferentiation of neurovascular relations in the neurohaemal area seems to be the reason for [areactivity] of the hypothalamo-hypophyseal system in young rats.

[Characteristics of neurosecretory centers of the rat hypothalamus associated with the regulation of adrenal cortex function]. / Kharakteristika neirosekretornykh tsentrov gipotalamusa krys, sviazannykh s reguliatsiei funktsii korkovogo veshchestva nadpochechnikov.

The reaction of neurosecretory cells of some hypothalamic centers of rats of different age to experimental change of the blood level of corticoids to elucidate their role in the regulation of function of the hypophyseoadrenocortical system was studied. Immunohistochemical methods revealed corticoliberin- and vasopressinergic cells in the hypothalamic paraventricular nucleus and vasopressinergic cells in the anterocommissural group of neurosecretory cells and in the supraoptic nucleus. The number of revealed corticoliberin-immunoreactive cells and the value of nucleoli of vasopressinergic cells served an indicator of the intensity of synthesis of neurohormones. In accordance with literature data there was an increase in the number of corticoliberin-immunoreactive cells after adrenalectomy. Vasopressinergic cells of the anterocommissural group were activated after true adrenalectomy. They responded by lowered activity to sham adrenalectomy. Small cell vasopressinergic elements of the paraventricular nucleus and, to a lesser degree, large cell elements responded by a rise of activity to true and sham adrenalectomy. It was assumed that vasopressinergic elements of the anterocommissural group were sensitive to the content of peripheral blood corticoids and were involved in the system of long negative feedback. Vasopressinergic elements, mostly small cells of the paraventricular nucleus, appeared to be responsible via the system of short negative feedback for maintaining the hypophyseal ACTH level.

[Adenosine triphosphatase activity in the osmoregulatory organs of vertebrates]. / Aktivnost' adenozintrifosfataz v osmoreguliruiushchikh organakh pozvonochnykh.

Studies have been made on the activity of cation- and anion-stimulated ATPases, as well as succinic dehydrogenase in homogenates and subcellular fractions from osmoregulatory organs of marine (elasmobranch and teleost) and freshwater (teleost) fishes, amphibians, reptiles, birds and mammals. The activity of Na+, K+-ATPase was found to be rather similar in almost all osmoregulatory organs of the species investigated. The highest level of Cl-stimulated ATPase was found in microsomal fraction of the kidneys from birds and mammals. Succinic dehydrogenase activity is significantly higher in the renal tissue of mammals, both in total homogenates and in mitochondrial fraction.

[Ultrastructure of the neurosecretory cells of the anterior commissural nucleus of the hypothalamus in rats]. / Ul'trastruktura neirosekretornykh kletok perednekomissural'nogo iadra gipotalamusa krys.

The ultrastructure of neurosecretory cells of the anterior commissural nucleus of rat hypothalamus is similar to that of the supraoptic nucleus and of the "magnocellular" part of the paraventricular nucleus. The only difference is a less expressed granular endoplasmatic reticulum and a smaller diameter of elementary neurosecretory granules (80-150 nm in diameter). Such elementary granules are characteristic of neurosecretory terminals located in the external zone of the median eminence. It is suggested that neurosecretory cells of the anterior commissural nucleus project to this neurohemal region.

[Relationship between the spawning process and quantitative ultrastructural analysis of the neurosecretory elements of the neurohypophysis of female Acipenser güldenstädti sturgeon]. / Kolichestvennyi ul'trastrukturnyi analiz neirosekretornyk élementov neirogipofiza samok osetra Acipenser guldenstadti v sviazi s protsessom neresta.

Quantitative studies have been made on functional condition of neurosecretory terminals in the neurohypophysis of sturgeon females during upstream migration, soon after spawning and 3 or more weeks after the latter. Electronmicroscopically, within each of the 3 types if neurosecretory terminals (A1, A2, B) certain forms were distinguished which correspond to separate phases of the secretory cycle; relative amounts of these forms were determined. Functional correlation in the activity of peptide- (A1, A2) and monoaminergic (B) terminals was observed which reveals itself in synchronous increase of the activity of peptidergic and the decrease in the activity of monoaminergic terminals immediately after spawning. At later stages, inactivation of all the 3 types of terminals takes place. Functional significance of this correlation is discussed in relation to double (peptide- and adrenergic) control of the activity of visceral organs during realization of protective and adaptive reactions of the organism under such natural stress conditions, as spawning.

[Median eminence of the hypothalamus in hypophysectomized rats: its structure and ultrastructure]. / Sredinnoe vozvyshenie gipotalamusa gipofizéktomirovannykh krys: struktura i ul'trastruktura.

The median eminence of the hypothalamus of intact and hypophysectomized rats has been studied by means of light and electron microscopy. Paraldehyde-fuchsin (PAF)-positive material is revealed in the external zone of the median eminence in 2-5 days after the operation. The PAF-positive material is also accumulated in the neurosecretory fibres localized around subependymal blood vessels. A2 fibres containing granules of 100-150 nm in diameter and B type fibres with granules up to 100 nm in diameter are seen in the external zone of the median eminence in intact rats. Besides, A1 fibres with granules of 120-200 nm in diameter are found near hypophyseal portal vessels in hypophysectomized animals. All type terminals make contact with blood vessels in the subependymal zone of the median eminence of hypophysectomized rats. It is suggested that terminals of the neurosecretory fibres of types A2 and B permanently make contact with the primary portal capillaries in the external zone of the median eminence, while A1 fibres ingrow in the median eminence in the course of postoperative reparation.

Ultrastructure of the sturgeon neurohypophysis. / O nekotorykh osobennostiakh ul'trastruktury neirogipofiza osetra

Three types of nerve fibres and their terminals have been revealed in the sturgeon neurohypophysis. Peptidergic A1 and A2 type fibres contain granules 120--200 and 100--160 nm in diameter, resp. Monoaminergic B type fibres have granules 80-100 nm in diameter. Terminals of A2 type predominate in the sturgeon neurohypophysis, A1 and B type terminals are a rarer occurrence. Different stages of exocytosis of the neurosecretory granule content were seen in the A1 and A2 type terminals. It is suggested that neurosecretory granules are the carriers of arginine-8-vasotocin and oxytocin-like polypeptide in A2 and A1 fibres, resp.

[Electron microscopic study of monoaminergic fibers in the posterior lobe of the rat hypophysis]. / Elektronno-mikroskopicheskoe issledovanie monoaminergicheskikh volokon v zadnei dole gipofiza krysy

Monoaminergic fibers and their swellings containing dense core vesicles, 700-1000 A in diameter, were found by electron microscopic studies in the posterior pituitary of rat. Most of them are situated far from capillaries and are surrounded by neurosecretory fibers and pituicytes. There are usually no specialized structures at the sites of contact between them. Single monoaminergic fibers come in contact with the capillaries and even penetrate the pericapillary space. Large swelling of these fibers which sometimes occur contain different polymorphous inclusions, degenerating mitochondria and numerous small tubules along with the dense core vesicles.

[Ultrastructure of the neurohypophysis in the lamprey, Lampetra fluviatilis L]. / Ul'trastruktura neirogipofiza u minogi Lampetra fluviatilis L

Three distinct zones are observed in the neurohypophysis (Nh) of adult lampreys: ependymal (tanycyte), fiber and neurovascular. The ependymal zone consists of a single layer of tanycyte perikarya. Their basal processes pass via the fiber zone and form vascular "endfeet" on the connective tissue layer, separating Nh and the meta-adenohypophysis. Few funnel-shaped protrusions of the recessus infundibuli lined with tanycytes penetrates deeply in Nh. Pituicytes are rare. Peptidergic A1 and A2 fibers and their terminals contain granules of 1600-3400 and 1200-2200 A in diameter respectively. Monoaminergic B type fibers have granules of 800-1000 A in diameter. Percentage of the A1 fibers is the lowest. Nerve terminals and tanycyte vascular "endfeet" make contact with the unusually thick (up to 3000 A) outer basement membrane. The latter is about 1 mu thick in sites where in invaginates deeply in Nh. Single short fragments of the inner basement membrane are seen. Sometimes peptidergic A1 and A2 nerve terminals are separated from the third ventricle or its protrusions only by a thin layer of tanycyte cytoplasm. Peptide neurohormones are probably released in the cerebro-spinal fluid in these sites. The possibility of peptide neurohormone and monoamine be discharged into the common circulation and their diffusion through the the connective tissue layer into the meta-adenohypophysis is discussed.