[The direct activating effect of a nonapeptide neurohormone (vasotocin) on the thyroid and interrenal glands of sturgeons in in-vitro experiments]. / Neposredstvennoe aktiviruiushchee vliianie nonapeptidnogo neirogormona (vazototsina) na shchitovidnuiu i interrenalovuiu zhelezy osetrovykh ryb v opytakh in vitro.

An in-vitro effect of nonapeptide neurohormone vasotocin on thyroid and interrenal glands was studied in hybrid of Siberian and Lena sturgeons [correction of salmons] at light microscopy level using morphometric method. At a concentration of 0.1 and 1 nmol/l vasotocin was shown to exert undirectional stimulating effect on the thyroid and interrenal gland functions. In the presence of vasotocin at a concentration of 1 nmol/l in culture media the activity of glands is even more pronounced than under the influence of adenohypophyseal hormones, adrenocorticotropic (8 x 10 ng/ml) and thyrotropic (5 ng/ml).

[The effect of factors of the supraoptic and paraventricular hypothalamic nuclei on the growth, cellular reproduction and cytodifferentiation of the adenohypophyseal epithelium]. / Vliianie faktorov supraopticheskikh i paraventrikuliarnykh iader gipotalamusa na rost, kletochnuiu reproduktsiiu i tsitodifferentsirovku épiteliia adenogipofiza.

In hypophysectomised noninbred [correction of inbred] rats and in male rabbits, a direct influence of stimulation with oxytocin, vasopressin, dopamine of the hypophysis substance's adenocytes enhanced their proliferation as well as the DNA synthesis. The role of hypothalamic nonapeptides as the regulators of cells and tissues homeostasis is discussed.

The hypothalamo-hypophyseal system in Acipenseridae. XI. Morphological and immunohistochemical analysis of nonapeptidergic and corticoliberin-immunoreactive elements in hypophysectomized sterlet (Acipenser ruthenus L.).

The regeneration of the hypothalamo-hypophyseal system (HHS) has been studied in the sterlet following hypophysectomy (HypoX). Significant portions of nonapeptide and corticoliberinergic (CRH) neurosecretory cells (NSCs) underwent degeneration. Surviving NSCs had a great regenerative ability; damaged axons formed anew, uncharacteristicly for intact fishes, axovasal and axoventricular contacts. There are some specific features of the reorganization of the ANHyp in sterlet after HypoX: (a) blood capillaries from the meninges penetrate deep into the wall of the infundibular recess and form unusual axovasal contacts; (b) "neurovascular regeneratory complexes" appear; (c) single CRH-immunoreactive axons grow into the meninges. Morphological data show progressive appearance of dendroventricular contacts in the preoptic nucleus, formation of new axoventricular and axovasal contacts, and activation of surviving NSCs after HypoX. An ability to recognize HHS to release neurohormones into the CSF and bloodstream is suggested.

[The morphofunctional specialization of the main and accessory magnocellular neuroendocrine nuclei of the hypothalamus]. / Morfofunktsional'naia spetsializatsiia glavnykh i dobavochnykh krupnokletochnykh neiroéndokrinnykh iader gipotalamusa.

Intensity of vasopressin gene expression was compared in neurosecretory cells of supraoptic, postoptic, paraventricular and 6 accessory nuclei (extrahypothalamic included) of adult intact Wistar rats to study the morphofunctional specialization of magnocellular hypothalamic nuclei. Messenger RNA (mRNA) was revealed by radioautographic in situ hybridization, using 35S labelled exonic-intronic probe. By densitometry the amount of label was shown not to differ significantly in neurosecretory cells of all nuclei studied. The latter reflects similar basal level of vasopressin gene expression in all magnocellular nuclei of intact rats. The explanations of this fact as well as possible perspectives of studying molecular biological basis of functional specialization of different magnocellular hypothalamic formations are discussed.

[A morphofunctional analysis of the nuclear apparatus of the nonapeptidergic neurosecretory cells in the vertebrate hypothalamus]. / Morfofunktsional'nyi analiz iadernogo apparata nonapeptidergicheskikh neirosekretornykh kletok gipotalamusa pozvonochnykh.

A vast comparative material obtained on fishes, amphibians and mammals has been analysed using ecological and experimental histophysiological approaches. The structural organization of the nuclear apparatus of nonapeptidergic neurosecretory cells, especially in the lower vertebrates has been clearly shown to differ from that of the classic neurones. Morphometrical characteristics of nonapeptidergic neurosecretory cells of hypothalamic centers can be used for a reliable evaluation of their functional conditions. A high intensity of protein metabolism in nonapeptidergic cells of magnocellular hypothalamic centers leads to a bigger nucleolus/nucleus relation for these cells in parvocellular centers. All this proves the necessity of the morpho-functional analysis of nuclear apparatus of neurosecretory cells.

[Nontraditional "large-cell" neuroendocrine formations (accessory nuclei) in the brain of Anamnia and Amniota]. / Netraditsionnye "krupnokletochnye" neironnye formatsii (dobavochnye iadra) v golovnom mozgu nekotorykh Anamnia i Amniota.

Using immunochemical PAP-method nonapeptidergic neuroendocrine formations in the hypothalamus and adjacent brain areas of fishes (the sterlet Acipenser ruthenus, the shark Scylliorhinus canicula), amphibians (the frog Rana temporaria), reptiles (the snake Natrix natrix), mammals (rats and dogs) and human have been studied. In Amniota and human accessory nuclei (AN) in addition to main "magnocellular" nuclei (supraoptic, postoptic and paraventricular) were discovered. Two AN, circular and dorsolateral ones, were found in snakes, and circular, dorsolateral, forniceal and extrahypothalamic AN were revealed in rat, dog and human brain. In Anamnia, sharks and frogs, in contrast to sterlets, the dorsolateral sub-nucleus inside preoptic nucleus was identified. AN similarity in the phylogenetic row of vertebrates and mechanisms of AN creation in phylo- and ontogenesis were discussed.

[The reaction of the nonapeptidergic neurosecretory cells of the hypothalamic accessory groups to cold and immobilization stresses in rats]. / Reaktsiia nonapeptidergicheskikh neirosekretornykh kletok dopolnitel'nykh grupp gipotalamusa na kholodovoi i immobilizatsionnyi stress u krys.

Male Wistar rats were subjected to stresses of two different kinds: cooling (2 h at 4 degrees C) or immobilization (20 min). In the rat hypothalamus, oxytocinergic (OTE) and vasopressinergic (VPE) cells were studied immunohistochemically (PAP-method) in following magnocellular accessory groups: circular (CG), perifornical (PFG), ventrolateral (VLG), dorsolateral (DLG), extrahypothalamic (EHG), and periventricularly localized OTE cells (PVC). In cooled rats, sizes of cellular nucleoli increased significantly in both OTE and VPE cells of the CG, EHG and PVC indicating activation of hormone production. The immobilization stress caused the reverse changes of morphometric characteristics in the groups. Signs of VPE cell activation were revealed after both cooling and immobilization in the PFG only. The cells of VLG and DLG did not change significantly under both stresses. It is concluded that the accessory groups of nonapeptidergic cells in the hypothalamus are functionally different and each of them is of particular significance in the organism. The role of the accessory groups for peripheral endocrine gland regulation is discussed.

[A morphofunctional study of the hypothalamic postoptic nucleus after hypophysectomy, cooling and immobilization in rats]. / Morfofunktsional'noe issledovanie postopticheskogo iadra gipotalamusa posle gipofizéktomii, okhlazhdeniia i immobilizatsii krys.

Response of the vasopressin (VP) and oxytocin (OT) cells of hypothalamic post optical nucleus (PON) was studied in male Wistar rats under various experimental conditions. Seven days after hypophysectomy, the majority of both VP- and OT-cells became pyknomorphic which seemed to be the result of transsection of the PON-cell axons and indicated that the PON-cells released neurohormones from the posterior pituitary into the blood. When rats were cooled (2 h at 4 degrees C), the size of nucleoli in VP-cells diminished significantly, but in rats stressed by severe immobilization (20 min) these cells revealed clear signs of activation. In contrast to that, no changes were observed in the OT-cells after these treatments. The functional relation of the PON and thyroid gland is discussed.

[The detection of corticoliberin in the neurosecretory cells of additional Gomori-positive centers in the rat hypothalamus]. / Vyiavlenie kortikoliberina v neirosekretornykh kletkakh Gomori-polozhitel'nykh dopolnitel'nykh tsentrov gipotalamusa krys.

The experiments were carried out in male Wistar rats in which deafferentation of the mediobasal hypothalamus was performed or colchicine (75 micrograms/10 microliters of saline) was inoculated into the III ventricle cavity. Using the PAP-method, the presence of corticoloberin was determined immunohistochemically in neurosecretory cells of additional groups (AG) of the hypothalamus: circular, perifornical (PFG), dorsolateral, ventrolateral, as well as extrahypothalamically located group (the internal capsule area). The intact rats were shown to have no corticoliberin-immunoreactive (CL-IR) cells in any of AG. After experimental treatments, CL-IR cells appeared in PFG only but not in any other AG. In the experimental rats, two types of CL-IR cells were demonstrated in PFG. The first type consisted of cells of 15-20 microns in diameter with processes, similar to those found in the paraventricular nucleus. The second type consisted of large cells (40-50 microns in diameter) with morphological features of nonapeptidergic ones whose cytoplasm gave a weak reaction with antiserum to corticoliberin. Thus, among AG of various localizations PFG alone contained CL-IR cells which indicated the involvement of this group into realization of the stress reaction.

The primary structure of sturgeon prolactin: phylogenetic implication.

The complete amino acid sequence of prolactin (PRL) from a chondrostean species, the sturgeon (Acipenser gueldenstaedti), has been determined. Sturgeon PRL was isolated from the pituitary glands by gel filtration on a Sephadex G-25 column and high-performance liquid chromatography on a reverse-phase column following acid-acetone extraction. Sturgeon PRL was identified by immunoblot reactivity using antisera against salmon and ovine PRL. It consists of 204 amino acid residues, which is the largest among known PRLs, and contains three disulfide bonds corresponding to those of tetrapod PRLs. Sequence comparison with PRLs from other vertebrates revealed that sturgeon PRL has slightly higher sequence identities (35-46%) with teleost PRLs than with tetrapod PRLs (30-40%). These structural characteristics imply that an ancestor of the ray-finned fishes had PRL with three disulfide bonds and at some point after divergence of Chondrostei, the disulfide bond in the amino-terminus of PRL was lost.