摘要:

AbstractThere is a significant rise in the blood glucose level ofChanna punctatusfollowing surgical extirpation of the principal islets. The hyperglycemia persists for nearly 30 days in the isletectomized fish. A transient hyperglycemia is exhibited by the sham operated control fish also. If the isletectomized fish are force‐fed, a further increase in the blood glucose level is obtained. The force feeding of normal, unoperated fish results in an alimentary hyperglycemia at about 10–24 hours post‐pra

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1972.tb00580.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractThe effects of gonadectomy on the cytological structure of the hypophysis and interrenal tissue ofClarias batrachushave been investigated. Forty days after gonadectomy remarkable hypertrophy of certain cyanophils, identified later as gonadotrops, has been observed followed by hyperplasia. The somatotrops also seem to undergo similar changes, and as a result the proximalpars distalis(PPD) increases enormously and encroaches upon thepars intermedia(PI). The gonadotrops undergo a gradual degranulation and become devoid of stainable cytoplasm by 90 days. No signet ring cells have been noticed at any stage. The cyanophils in the ventral region of the PPD, identified as thyrotrops, also show degranulation, but to a comparatively limited degree.The ACTH cells undergo gradual hypertrophy and degranulation. A progressive increase is noticed in the nuclear diameter. The interrenal cells are activated as indicated by the enhanced nuclear indices. It is suggested that a fall in gonadal steroids may result in ACTH release which in turn activates the interrenal cells.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1972.tb00581.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractThe Reissner's fibre of the cow combines two types of protein at least:— a fibrous one of high molecular weight, which molecules are connected one another by disulfide bridges and by relatively stable noncovalent links.— a second one of lower molecular weight associated with the first one by noncovalent links only.Both proteins contain carbohydrates bound O‐glycosidically probably. The solution of the Reissner's fibre substance tends to reaggregate in a high degree. This fact is discussed in reference to the manner of formation of the Reissners's fibre in vivo.ZusammenfassungDer Reissnersche Faden des Rindes besteht aus mindestens zwei Protein typen:— ein hochmolekulares, fibrilläres Protein, dessen Moleküle untereinander über Disulfidbrücken und darüber hinaus relativ fest über nichtkovalente Bindungen vernetzt sind;— ein Protein von geringerer Molekülgröße, das mit dem erstgenannten Protein allein über nichtkovalente Bindungen assoziiert ist.Beide Proteine enthalten Kohlenhydrate, die vermutlich O‐glykosidisch gebunden sind. Die gelöste Reissnersche‐Faden‐Substanz neigt in hohem Maße zur Reaggregation — eine Erscheinung, die im Zusammenhang mit der Bildung des Reissne

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1972.tb00582.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractTheneglecta, a small labyrinthine sensory end organ, was examined in 11 avian species. The ultrastructure of this sensor) area was studied in 3 species and was found to be similar to other vestibular sensory epithelia so far described. The nerve‐enclosed sensory cells (type I) are randomly distributed. The sensory cells are all polarized utriculo‐fugally, as are also the sensory cells in the crista ampullaris posterior. Finally, some reasons are given for designating the sensory areacrista neglecta.ZusammenfassungDie Neglecta, eine kleine Sinnesendstelle des Labyrinthes, ist an 11 Vogelarten untersucht worden. Die Ultrastruktur, elektronenmikroskopisch an 3 Arten untersucht, ist dieselbe die früher in anderen vestibulären Sinnesepithelien gefunden ist. Die Sinneszellen Typ I sind nicht in speciellen Zonen konzentriert, sondern regelmässig distribuiert. Alle Sinneszellen sind utriculo‐fugal polariziert, wie auch die Sinneszellen der Crista amp. posterior. Schliesslich werden einige Gründe für die Anwendung der Bezeichnung Crista neglec

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1972.tb00583.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractThe fine structure of the the optic tract inMyxine glutinosawas studied in three animals. The nerve fibers are unmyelinated and occur either singly or in groups surrounded by glial cytoplasm. 810 and 1467 nerve fibers were counted in two tracts. In the zone where the optic tract leaves the eye cup, a cell type is described and suggested to correspond to ganglion cells. Presynaptic terminals containing agranular vesicles were seen adjacent to this cell type and to other processes in the area. The results are discussed in view of previous reports.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1972.tb00584.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractExtracts of adenohypophyses ofMyxine glutinosawere tested on webs ofXenopus laeviswith regard to melanophore‐dispersing activity. In two out of five experiments pigment granule dispersion and aggregation were obtained when test webs were placed in extracts and saline solution, respectively. The possible occurrence and location of a melanophoredispersing substance is dicussed in view of previous investigation

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1972.tb00585.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractCortisol administration (1 mg/day, 1 to 28 injections) induces several hypophyseal modifications in freshwater male eels and their skin turns silver although the ventral face was already silvered.Corticotrophs are rapidly degranulated, smaller with a reduction of the nuclear area (14.4%, 18.25 ± 0.3 to 15.61 ± 0.31 μm2, P<0.001) after 9 injections and up to 28. Growth hormone‐secreting cells appear smaller, often degranulated, but no nuclear atrophy is detected. Gonadotrophs are slightly stimulated and more abundant, a result which may be correlated with a picture of activity in the nucleus lateralis tuberis and the beginning of gonadal development (organs of Syrski). Prolactin cells appear very active, thyrotrophs may be less active in some animals. In the pars intermedia, MSH (melanophorostimulating hormone) cells progressively become degranulated, with a reduced nuclear diameter (4.73 ± 0.03 to 4.45 ± 0.03 μm, P<0.001) after 6 injections and more. Their hypoactivity may play a role in the skin silvering process. There is a tendency towards a reduction of the amount of neurosecretory material in the neurohypophysis of some animals.Data collected on the picture of hypoactivity in the corticotrophs, growth hormone‐secreting cells, and MSH cells and skin silvering are compared with those obtained on other Vertebrates.RésuméL'injection de Cortisol (1 mg/j, 1 à 28 injections) provoque chez l'Anguille mâle en eau douce une argenture très marquée de la peau et des modifications hypophysaires.Les cellules corticotropes sont rapidement dégranulées et moins volumineuses, la surface nucléaire est réduite de 14,4 % (P<0,001) après 9 injections et plus. Les cellules somatotropes sont généralement plus petites, souvent dégranulées, mais sans atrophie nucléaire décelable. Les éléments gonadotropes sont un peu stimulés et plus abondants; ce fait peut être relié à un aspect plus actif des noyaux tubériens et à l'ébauche de développement des organes de Syrski. Les cellules à prolactine sont très actives, les éléments thyréotropes parfois moins actifs. Dans lapars intermedia, les cellules MSH (hormone mélanophorique) deviennent moins granulées et le diamètre nucléaire est réduit après 6 injections et plus. Leur hypoactivité peut jouer un rôle dans l'argenture observée. La quantité de neurosécrétat dans la neurohypophyse diminue chez quelques animaux.Ces résultats concernant l'hypoactivité des cellules corticotropes, somatotropes et MSH et l'argenture corporel

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1972.tb00586.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractThe background adaptation ability in intact skates,Raja radiata, is extremely variable. Many specimens take several days for adaptation, whereas some show rapid and distinct responses. The dermal and epidermal melanophores do not always react simultaneously. Neurointermediate lobectomy abolishes the black‐background response. Injection of neuro‐intermediate lobe extracts and pure α‐MSH into these specimens result in temporary darkening, but the paling time is different in these two types of trea

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1972.tb00587.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractFour cell types are present in the olfactory epithelium ofNeoceratodus forsteri, i.e., olfactory receptor cells, supporting cells, non‐sensory ciliated cells, and basal cells. Only microvilli and no cilia were observed on the receptor cells. The neurotubules pass out into these microvilli. Conspicuous arrays of agranular endoplasmic reticulum are present in the nuclear region of the receptor cells. The supporting cells are provided with microvilli. These cells may be secretory. The non‐sensory ciliated cells produce secretory granules containing acid mucopolysaccharides. A discontinuous zonula occludens appears to be pres

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1972.tb00588.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

AbstractThe absorbing capability of the choroidal epithelium in the third and the fourth ventricles of the teleostLeuciscus rutiluswas studied by using the electron dense tracers lanthanum and peroxidase. The tracers were either injected into the third ventricle or applied onto the leptomeninx. Peroxidase was rapidly absorbed by coated vesicles after being injected into the ventricle. This reaction product was retained in multivesicular bodies which remained localized at the apical pole of the cell. However, when peroxidase was applied onto the leptomeninx only a limited uptake was observed. Lanthanum was not absorbed by the epithelial cells. Thezonulae occludentesbetween two adjacent cells prevented the tracers from reaching the ventricular or vascular sides. Thus, the epithelium of thesaccus dorsalisand theplexus choroideus posterioract as a barrier prohibiting the transport of these tracers from the blood to the cerebrospinal fluid or also in the reverse direction.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1972.tb00589.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY