ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1990.tb00345.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The physiological response and ultrastructure of the pigment cells ofTrematomus bernacchii, an Antarctic teleost that lives under the sea ice north of the Ross Ice Shelf, were studied. In the integument, two types of epidermal chromatophores, melanophores and xanthophores, were found; in the dermis, typically three types of chromatophores—melanophores, xanthophores, and iridophores—were observed. The occurrence of epidermal xanthophore is reported for the first time in fish. Dermal melanophores and xanthophores have well‐developed arrays of cytoplasmic microtubules. They responded rapidly to epinephrine and teleost melanin‐concentrating hormone (MCH) with pigment aggregation and to theophylline with pigment dispersion. Total darkness elicited pigment aggregation in the majority of dermal xanthophores of isolated scales, whereas melanophores remained dispersed under both light and dark conditions. Pigment organelles of epidermal and dermal xanthophores that translocate during the pigmentary responses are carotenoid droplets of relatively large size. Dermal iridophores containing large reflecting platelets appeared to be i

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1990.tb00259.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARYMelanogenesis, i.e., synthesis of melanin and melanosomes, is a “cascade'’of event which is channelled by internal and external regulatory factors. The recognition and selection of this information and subsequent differentiation of melanogenesis (melanin type and melanosomal development) would be regulated significantly by melanosomal membrane. The melangenesis type could be switched relatively easily by UV light, hormone, and availability of tyrosinase substrate. The role of sulphydryl compounds as a regulatory factor in melangenesis type (in particular for pheomelanogenesis) may not be tied to its absolute presence or absence, but rather, to the effective concentration within the melanocyte at a given time. It is, therefore, probable that the morphogenesis of melanosomes may not follow immediately in response to melanogenesis‐type changes, hence the melanocyte revealing more often mosaic forms of melanosomes in nature after exposure to non‐genetic factors. The switch of melanogenesis would be significantly controlled by structural and functional availability of vesiculoglobular bodies which are encoded or associated with HMSA‐5 (69 kDa) glycoprotein. This HMSA‐5 protein shares a significant homology with gp75 “b‐locus'’protein. However, because of our hypothesis that vesiculoglobular bodies carry post‐(and pre‐) tyrosinase regulatory factors involving in both pheo‐ and eumelanogenesis, the term “b‐protein'’which focuses only on eumelanogenesis

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1990.tb00346.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Solar radiation induces numerous biologic effects in skin but the mechanism underlying these responses is poorly understood. To study the etiology of these phenomena, we investigated the effect of light on culturedXenopus laevismelanophores. Visible light stimulated a marked increase in intracellular cAMP levels within the first minute of irradiation. This light‐induced elevation in cAMP was blocked by melatonin and was not seen in fibroblasts irradiated in a similar manner. These data show that the photoresponse of pigment cells from amphibian skin can be mediated by a cAMP‐dependent mechanism and suggest that a unique member of the rhodopsin family is involved in this proc

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1990.tb00260.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1990.tb00347.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Three human melanoma cell lines of differing invasive and metastatic potentials were cultured on either a plastic surface or a denuded amniotic basement membrane, and alterations in their cell surface proteins, invasive profiles, and the presence or absence of the 69 Kd high‐affinity metastasis‐associated laminin receptor were examined. Our data indicate that the labeled, precipitatable cell surface proteins are different from the three cell lines when they are cultured on the same substrate, and change when the cells are cultured on a different substrate. Furthermore, the invasive potential (as measured in the in vitro Membrane Invasion Culture System) is decreased for all of the cell lines after culturing the cells on a basement membrane matrix compared to a plastic surface. Finally, we show that the 69 Kd high‐affinity metastasis‐associated laminin receptor can be isolated from all three cell lines cultured on the two different substrates by labeling the cell surface with trinitrobenzene sulfonic acid and immunoprecipitating these targeted p

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1990.tb00261.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1990.tb00348.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1990.tb00349.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1990.tb00350.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0893-5785    

DOI:10.1111/j.1600-0749.1990.tb00351.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY