Expression and localization of the vascular endothelial growth factor and changes of microvessel density during hair follicle development of Liaoning cashmere goats.

Vascular endothelial growth factors (VEGFs) play important roles in neovascularization, tissue development, and angiogenesis. In this study, changes in VEGF expression patterns and microvessel density (MVD), and their correlations, were investigated during hair follicle development in epidermal appendages of Liaoning cashmere goats. Polyclonal antibodies to VEGF and microvessels were used for monthly immunohistochemical examinations of normal skin specimens from adult female goats for one year. VEGF was expressed in the hair bulb of primary and secondary hair follicles, the outer and inner root sheaths, sebaceous glands (ductal and secretory portions), eccrine sweat glands (ductal and secretory portions), and the epidermis. Abundant expression of VEGF was observed in the follicular basement membrane zone surrounding the bulb matrix and in ductal and secretory portions of eccrine sweat glands. The change in VEGFs in primary hair follicles showed a bimodal pattern, with the first peak observed from March to May, and the second in August. Maximal expression in secondary hair follicles occurred in May and August. Therefore, VEGF expression in primary and secondary hair follicles is synchronized throughout the year, and is correlated to hair development. In the later telogen and anagen phases, VEGF expression was higher in the secondary, compared to the primary, hair follicle. Changes in MVD also showed a bimodal pattern with peaks in May and August. VEGF expression and MVD showed moderate and strongly positive correlation in the primary and secondary hair follicles, respectively. Therefore, MVD and VEGF are closely related to the processes involved in hair cycle regulation.

Irrigação da glândula uropigiana em aves domésticas (Gallus gallus domesticus) da linhagem Cobb / Irrigation of uropigian gland of domestic fowls (Gallus gallus domesticus) of Cobb lineage

Avaliou-se a vascularização arterial da glândula uropigiana em 34 aves (Gallus gallus domesticus), da linhagem Cobb, objetivando estudar a origem dos vasos sangüíneos colaterais a ela endereçados, e de seus respectivos territórios de distribuição. O material foi doado pela empresa Globo Aves, sediada em Uberlândia – MG. Os espécimes tiveram seus contingentes arteriais injetados com solução corada de neoprene látex, por meio de cânulas de polietileno, a partir da artéria isquiática esquerda. Na seqüência injetou-se uma solução aquosa de formol a 10%, vias subcutânea e intracavitária, o que possibilitou a fixação do material. Finalmente procedeu-se individualmente a dissecação da região circunscrita à glândula uropigiana. Oportunamente utilizou-se uma lupa monocular para observação dos vasos presentes no parênquima glandular e, conseqüentemente chegou-se a um padrão de distribuição vascular. A glândula uropigiana mostrou-se irrigada através da artéria mediana caudal em todos (100%) os animais, por meio de seus ramos intersegmentares, que emitiram os ramos glandulares laterais direito e esquerdo e mediais direito e esquerdo, estes ainda originaram os sub-ramos os quais foram numerados em escala crescente segundo o sentido latero-medial. Estes ao se dividirem deram origem a ramos que foram numerados em ordem crescente seguindo o sentido latero-medial, precedidos do número do sub-ramo (por exemplo, sub-ramo 1 dá origem a dois outros pequenos vasos, vasos 1,1 e 1,2). Constatou-se um maior número de colaterais ocupando o antímero glandular direito a partir dos ramos mediais direitos 1,1 e 1,2; já no esquerdo, a maior ocorrência procedeu-se a partir dos ramos mediais esquerdos 1,1 e 1,2.

In this study was evaluated the vascular system of uropigian gland in 34 fowls (Gallus gallus domesticus), of Cobb lineage. The material was donated by the firm Globo Aves, located in Uberlândia – MG. Was specially studied the origin of collaterals that are aimed to that gland. Animals had them arterial contingents injected with a colored solution of neoprene latex, by polyethylene canulas through the right isquiatic artery. Then was injected an aqueous solution of formol 10%, in subcutaneous and intracavity spaces, which made possible the material fixation. Finally was proceeded the individually dissection of circumscribed region of uropigian gland. Opportunely was used a monocular lens in observation of vascular profile and was prepared schematics models representing the irrigation of each fowl. Uropigian gland showed itself as irrigated by mediana caudal artery in all (100%) animals, through its intersegmentaries branches, which emit right and left lateral glandular branchs and, right and left medials. Was countedthe sub-branches, and was verified bigger emission in the right by the M.D. 1,1 and 1,2; and in the left by the M.E. 1,1 and 1,2.

Demonstration of NADPH-diaphorase (NO-synthase) in sebaceous glands of the mammalian integument, with remarks on the glandular capillary net.

The study demonstrates weakly to strongly positive reaction staining for NADPH-diaphorase/NO- synthase in the peripheral cells of sebaceous glands in the hairy skin of domesticated mammals. Additionally, the structure of the blood capillary system surrounding these glands is better elucidated. The results obtained are discussed in view of a modulatory action of NO generated by these enzyme activities, implying a direct influence of this substance on the contractile elements of gland-associated blood capillaries. In this way, a simple and self-regulatory mechanism to couple blood flow and glandular metabolism can be proposed.

Fenestrated capillaries in the ventral sebaceous gland of the Djungarian hamster, Phodopus sungorus.

The ventral sebaceous gland of the Djungarian hamster is a macroscopically visible organ situated in the midventral area of the abdominal wall. It consists of densely packed acini arranged in lobules with common excretory ducts. The rich vascular network of the gland is characterized by fenestrated capillaries. Fenestrated endothelium has not yet been reported as a characteristic and regular finding within sebaceous glands. Results are discussed with regard to proliferation rate of sebocytes and the demand of fluid and nutrient supply.

Arteriovenous anastomoses in the skin of tropical cattle.

As part of a general study of the vascular arrangement in the skin of cattle in tropical environments, the arteriovenous anastomoses (AVA) and other specialized vascular structures in the various skin sites of cattle were observed histologically. AVA were abundant in the skin from the scrotum, eye margin and the lower limb sites but were generally less numerous on the hairy body skin sites of cattle. Most of the AVA, especially those in the scrotal skin, were complex and tortuous S-shaped vessels, mainly located in the mid- and lower reticular layer and the mid- and lower papillary layer. The possible significance of their presence in various body sites, especially on the scrotal skin, is discussed.