Revista Biotemas, 22 (2), junho de 2009 127 Morphology of the buffalo pineal gland Macro-microscopical aspects of the buffalo (Bubalus bubalis Linnaeus, 1758) pineal gland Ana Flávia de Carvalho 1 * Carlos Eduardo Ambrósio 2 Maria Angélica Miglino 2 Celina Almeida Furlanetto Mançanares 1 Francisco Javier Hernandez Blazquez 2 1 Centro Universitário da Fundação de Ensino Octávio Bastos Faculdade de Medicina Veterinária Av. Octávio Bastos s/n, Campus II, CEP 13 870-000, São João da Boa Vista – SP, Brazil 2 Universidade de São Paulo, Faculdade de Medicina Veterinária Departamento de Cirurgia, Anatomia dos Animais Domésticos e Silvestres Av. Orlando Marques de Paiva, 87, CEP 05508-270, São Paulo – SP, Brazil *Author for correspondence anaflaviac@uol.com.br Submetido em 07/05/2008 Aceito para publicação em 20/11/2008 Abstract Gross and microscopical aspects of the buffalo pineal gland were described in seasonal parturition animals, since this gland is responsible for melatonin secretion which acts upon the hypothalamus-hypophysis reproductive axis feedback system. (Hafez, 1995). For the present study, 11 cross-bred buffaloes, predominantly of the Mediterranean breed, from the Pirassununga Campus - USP (University of São Paulo), were killed in different photoperiods in the slaughterhouse. The pineal glands were obtained, fixed, weighed, measured, photographed, processed, cut into sections and stained. All glands demonstrated the same global shape, with a mean length of 8.82 ± 1.07mm and a width of 7.91 ± 0.83mm, and a stem length of 5.50 ± 4.18mm. The stems had a microscopically visible lumen. The mean gland weight was 251.45 ± 83.1mg. The buffalo pineal gland presented right and left lobes of different sizes. Microscopically, they were surrounded by a connective tissue layer with blood vessels infiltrating into the glandular parenchyma, which became separated into glial cell lobules. A great number of the pinealocytes were arranged in irregular strings, and cells from the connective tissue could be observed in the glandular parenchyma. We conclude that the buffalo pineal gland is similar to that of pineal cows and that it does not show morphologic alterations during different photoperiods of the year. Key words: pineal gland, buffalo, pinealocytes Resumo Aspectos macro e microscópicos da glândula pineal de búfalos (Bubalus bubalis Linnaeus, 1758). Os aspectos macro e microscópicos da glândula pineal de búfalos adultos foram descritos em animais que apresentavam partos sazonais, sabendo-se que esta glândula é responsável pela secreção de melatonina atuando Biotemas, 22 (2): 127-135, junho de 2009 ISSN 0103 – 1643