Histomorphometric examination of the pineal gland in foals and adult horses

Abstract

This study was conducted to evaluate the pineal glands of the foal and adult horses with histomorphometry. The pineal glands were sectioned at a thickness of 40 µm and stained with AgNOR for stereological analyses. The weight and volume of the pineal gland as well as the number of pinealocytes were significantly higher in the adult horses (P=0.009). However, the number of pinealocytes in per volume was similar between foals and adult horses. Such data indicate that growth in the size of the gland is related to increase in the number of pinealocytes. The pinealocyte nucleus is significantly larger in adults (P= 0.009). Such a size difference should be further investigated if it is due to an increase in the number of cells with increased DNA content. Melanin was distributed throughout the foal pineal gland whereas it was focally localized to connective tissue in adults. The different patterns in melanin distribution suggest that foals and adult horses may differ by means of melanin metabolism in the pineal gland

Keywords

• Aging
• histochemistry
• pinealocyte
• stereology

Glandula pinealis’in taylarda ve ergin atlarda histomorfometrik olarak incelenmesi

Abstract

Bu çalışma, tayların ve yetişkin atların pineal bezlerinin histomorfometrik olarak incelenmesi amacıyla yapılmıştır. 40 μm kalınlığında alınan kesitler, stereolojik analizler için AgNOR ile boyandı. Yetişkin atlarda pineal bezin ağırlığı, hacmi, ve pinealosit sayısı anlamlı derecede yüksek bulundu (P = 0.009). Bununla birlikte, hacim başına düşen pinealosit sayısı tay ve yetişkin atlarla benzerdi. Bu veriler, pinealosit sayısındaki artışa bağlı olarak bezin büyümesine işaret etmektedir. Pinealosit çekirdeği yetişkinlerde belirgin olarak daha büyüktü (P=0.009). Bu durum DNA içeriği artmış hücrelerin sayısının artmasından kaynaklanıyorsa böyle bir boyut farklılığı daha fazla araştırılmalıdır. Melanin, tay pineal bezinin her bölgesine dağılmış bir durumda idi, ancak yetişkinlerde stromanın bağ dokusuna dağılmış vaziyette idi. Melanin dağılımındaki farklılıklar, pineal bezdeki melanin metabolizmasının taylarda ve yetişkin atlarda farklılık gösterebileceğini düşündürmektedir

Keywords

• Histokimya
• pinealosit
• stereoloji
• yaşlanma

References

1. Al-Hüssain SM (2006): The pinealocytes of the human pineal gland: A light and electron microscopic study. Folia Morphol, 65, 181-187.
2. Boya J, Calvo JL, Rancano D (1995): Structure of the pineal gland in the adult cat. J Pineal Res, 18, 112-118.
3. Calvo J, Boya J, Garcia-Maurino A, et al. (1990): Postnatal development of the dog pineal gland. Light microscopy. Histol Histopathol, 5, 31-36.
4. Capucchio MT, Marquez M, Pregel P, et al. (2010): Parenchymal and vascular lesions in ageing equine brains: Histological and immunohistochemical studies. J Comp Pathol, 14, 61-73.
5. Cozzi B, Ferrandi B (1984): The pineal gland of the horse. Morphological and histochemical results. (With notes on the donkey and mule pineal). Basic Appl Histochem, 28, 81- 90.
6. Cozzi B (1986): Cell types in the pineal gland of the horse: An ultrastructural and immunocytochemical study. Anat Rec, 216, 165-174. 7. Culling CFA, Allison RT, Barr WD (1985): Carbohydrates. 214-255. In: Culling CFA, Allison RT, Barr WD (Ed), Cellular Pathology Technique. Butterworth & Co. (Publishers) Ltd, London.
7. Denk H, Kunzele H, Plenk H, et al. (1989): Romeis Mikroskopische Technik. Urban and Schwarzenberg, München.
8. Elias HD, Hyde DM (1983): A Guide to Practical Stereology. S. Karger AG, Basel.

9. Flood DG, Coleman PD (1988): Neuron numbers and sizes in aging brain: Comparisons of human, monkey, and rodent data. Neurobiol Aging, 9, 453-463.
10. Gundersen HJ, Jensen EB, Kieu K, et al. (1999): The efficiency reconsidered. J Microsc, 193, 199-211. sampling in stereology
11. Gundersen, HJ (1977): Notes on the estimation of the numerical density of arbitrary profiles: The edge effect. J Microsc, 111, 219-223.
12. Gusek W, Meier D (1988): Size of the cell nucleus and nucleus-cytoplasm relations in pinealocytes in humans of middle and advanced age. Z Gerontol, 21, 79-82.
13. Hayasaka K (1988): Electron-microscopic observations on pinealocytes in various regions of the pineal gland of young and adult mice. Hokkaido J Med Sci, 63, 115-129.
14. Hira Y, Sakai Y, Matsushima S (1989): Comparisons of sizes of pinealocyte nuclei and pinealocytes in young and adult Chinese hamsters (Cricetulus griseus) under different photoperiod conditions. J Pineal Res, 7, 411-418.
15. Hughes SW (2005): Archimedes revisited: A faster, better, cheaper method of accurately measuring the volume of small objects. Phys Educ, 40, 468-474.
16. Jastrow H, Von Mach MA, Vollrath L (1997): Adaptation of the disector method to rare small organelles in TEM sections exemplified by counting synaptic bodies in the rat pineal gland. J Anat, 191, 399-405.
17. Khavinson VK, Linkova N (2012): Morphofunctional and molecular bases of pineal gland aging. Hum Physiol, 38, 101-107.
18. Koshy S, Vettivel S (2001): Melanin pigments in human pineal gland. J Anat Soc India, 50, 122-126.
19. Ploton D, Menager M, Jeannesson P, et al. (1986): Improvement in the staining and in the visualization of the argyrophilic proteins of the nucleolar organizer region at the optical level. Histochemical J, 18, 5-14.
20. Pontén J, Stein WD, Shall SA (1983): Quantitative analysis of the aging of human glial cells in culture. J Cell Physiol, 117, 342-352.
21. Redondo E, Regodon S, Masot J, et al. (2003): Postnatal development of female sheep pineal gland under natural inhibitory photoperiods: An immunocytochemical and physiological (melatonin concentration) study. Histol Histopathol, 18, 7-17.
22. Reiter RJ (1991): Pineal gland interface between the photoperiodic environment and the endocrine system. Trends Endocrin, 2, 13-19.
23. Santamarina E (1958): Melanin pigmentation in bovine pineal gland and its possible correlation with gonadal function. Can J Biochem Physiol, 36, 227-235.
24. Schmitz C, Hof PR (2000): Recommendations for straightforward and rigorous methods of counting neurons based on a computer simulation approach. J Chem Neuroanat. 20, 93-114.
25. Swietoslawski J (1999): The age-related quantitative ultrastructural changes in pinealocytes of gerbils. Neuro Endocrinol Lett, 20, 391-396.
26. Totty BA (2002): Mucins. 163-200. In: Bancroft JD, Gamble M (Ed), Theory and Practice of Histologycal Techniques. Churchill Livingstone, Edinburg.
27. West MJ, Slomianka L, Gundersen HJ (1991): Unbiased stereological estimation of the total number of neurons in the subdivisions of the rat hippocampus using the optical fractionator. Anat Rec, 231, 482-497.
28. Winick M, Rosso P, Waterlow J (1970): Cellular growth of cerebrum, cerebellum, and brain stem in normal and marasmic children. Exp Neurol, 26, 393-400.