Leptin (Lep) stimulates keratinocytes to proliferate, intervenes in the wound healing and participates to hair follicle morphogenesis and cycle. While it is secreted by skin structures including epidermis and hair follicles, intradermal adipose tissue also seems to have a role in Lep secretion and accordingly in the control of hair follicle growth in mice and humans. Lep was investigated in the skin of humans and laboratory animals but there are not data regarding bovine species. The aim of this work was to study the expression of Lep and its receptor (LepR) in the skin of bovine and, at the same time, to investigate the presence and extension of intradermal adipose tissue. A morphological evaluation of the skin was performed while the presence and localization of Lep and LepR were analyzed by RT-PCR and immunohistochemistry. A high and thick dermis without adipocytes was observed. Hair follicles and sebaceous and sweat glands were located in the proximal part of the skin while a thick layer of connective tissue, lacking adipose cells, separated these structures by subcutis. RT-PCR evidenced the transcripts for both molecules. By immunohistochemistry, Lep and LepR were observed in the epidermis and hair follicles. Based on the absence of intradermal adipose tissue and the presence of both Lep and LepR in the epidermis and in the hair follicle epithelium, it can be posited that in bovine skin Lep participates to the control of epidermis growth and hair follicle cycle through a paracrine and autocrine mechanisms.

中文翻译：

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牛皮肤激素瘦素的上皮表达。

瘦素（Lep）刺激角质形成细胞增殖，干预伤口愈合，并参与毛囊形态发生和循环。尽管它是由包括表皮和毛囊的皮肤结构分泌的，但皮内脂肪组织似乎在Lep分泌中也起着作用，因此在控制小鼠和人类的毛囊生长中也起作用。对人类和实验动物的皮肤中的Lep进行了调查，但没有有关牛物种的数据。这项工作的目的是研究Lep及其受体（LepR）在牛皮肤中的表达，同时研究皮内脂肪组织的存在和扩展。进行皮肤形态学评估，同时通过RT-PCR和免疫组织化学分析Lep和LepR的存在和定位。观察到没有脂肪细胞的高而厚的真皮。毛囊，皮脂腺和汗腺位于皮肤的近端，而一层厚的缺乏脂肪细胞的结缔组织通过皮下组织将这些结构隔开。RT-PCR证明了两个分子的转录本。通过免疫组织化学，在表皮和毛囊中观察到Lep和LepR。根据皮内脂肪组织的缺乏以及表皮和毛囊上皮细胞中Lep和LepR的存在，可以推断Lep在牛皮肤中通过旁分泌因子参与了表皮生长和毛囊周期的控制。自分泌机制。毛囊，皮脂腺和汗腺位于皮肤的近端，而一层厚的缺乏脂肪细胞的结缔组织通过皮下组织将这些结构隔开。RT-PCR证明了两个分子的转录本。通过免疫组织化学，在表皮和毛囊中观察到Lep和LepR。根据皮内脂肪组织的缺乏以及表皮和毛囊上皮细胞中Lep和LepR的存在，可以推断Lep在牛皮肤中通过旁分泌因子参与了表皮生长和毛囊周期的控制。自分泌机制。毛囊，皮脂腺和汗腺位于皮肤的近端，而一层厚的缺乏脂肪细胞的结缔组织通过皮下组织将这些结构隔开。RT-PCR证明了两个分子的转录本。通过免疫组织化学，在表皮和毛囊中观察到Lep和LepR。基于皮内脂肪组织的缺乏以及表皮和毛囊上皮细胞中Lep和LepR的存在，可以推测Lep在牛皮肤中通过旁分泌因子参与了表皮生长和毛囊循环的控制。自分泌机制。