Journal of Endocrinology and Reproduction

Rakesh Verma ¹, Vijay Kumar Verma ¹, Chandana Haldar ¹

Affiliations
1 Pineal Research Laboratory, Department of Zoology, Centre of Advanced Study Banaras Hindu University, Varanasi – 221005, IN

Abstract

Steroidogenic organs such as adrenal gland and gonad are of vital importance in birds, as the adrenal gland regulates stress by modulating the levels of corticosterone, while gonads synthesize gonadal steroids that regulate breeding cycle. Cholesterol content in both adrenal and gonad reflect the physiological status of these organs for stress management and reproduction, respectively. Birds, being photosensitive, experience phototoxicity in the nature due to the rapid urbanization. If photic stress induced by constant dark (DD) and constant light (LL) influences steroidogenesis in terms of cholesterol content and total antioxidant status (TAS%) as a marker of stress was experimentally assessed in Indian spotted finch Lonchura punctulata along with measurement of peripheral corticosterone levels. DD was stressful and, hence, caused decrease of ovary / testis weight and increase of adrenal gland weight, while cholesterol content decreased significantly due to inhibition of steroidogenesis. LL stimulated gonadal function but caused decrease of cholesterol content suggesting active steroidogenesis. TAS% increased under DD and decreased under LL. The phototoxicity, whether in term of DD or LL, was stressful to Indian spotted finch as evident from increased adrenal gland weight and decreased cholesterol content that can be correlated with increased synthesis of corticosterone. It may be concluded that cholesterol content is an important marker of streroidogenic status, and extremes of photoperiod influence cholesterol content, corticosterone level and TAS%.

Keywords

Cholesterol, Corticosterone, Photic-Stress, Spotted-Finch, Steroidogenic-Organs, TAS%.

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Sunanda Dubey ¹, Rakesh Verma ¹, Shraddha Rastogi ², Chandana Haldar ²

Affiliations
1 Department of Zoology, Udai Pratap Autonomous Degree College, Bhojubir, Varanasi-221002, IN
2 Pineal Research Laboratory, Department of Zoology, Banaras Hindu University, Varanasi - 221005, IN

Abstract

Mostly studied in the hamster, the Harderian gland (HG, an extra-orbital gland) has been shown to be capable of melatonin (MEL) synthesis and to possess steroid receptor binding sites. Sexual dimorphism and ability to respond to steroid hormones have been reported for HG of some temperate zone mammals. However, to date there is no report on functional relation of HG with pineal, pituitary and gonad in any rodent. Hence, we tested the effect of gonadotropins [FSH (10μg) + LH (10μg)] and steroids [testosterone (100μg) and 17-β estradiol (50μg)] on HG function in relation to the activities of the pineal gland and gonad in both sexes of Indian palm squirrel Funambulus pennanti during the sexually quiescent phase. In general, squirrels treated with gonadotropins and gonadal steroids showed a significant increase in gonadal weight and decrease in pineal weight and plasma melatonin level in LH- and testosterone-treated groups only. There was no change in the weight of HG on FSH treatment. Porphyrin content of HG decreased after testosterone and estradiol treatment. Pineal gland weight invariably decreased after treatment with gonadotropins and testosterone. Plasma testosterone and estradiol levels increased but melatonin level decreased in all treated groups. Our data suggest that in this tropical rodent gonadotropins have an indirect effect on HG and that gonadal steroids have significant effect on HG through the influence on gonadal and pineal functions.

Keywords

Gonadotropins, Harderian Gland, Melatonin, Pineal, Rodent.

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Sunanda Dubey ¹, Rakesh Verma ², Chandana Haldar ²

Affiliations
1 Department of Zoology, Udai Pratap Autonomous Degree College, Bhojubir, Varanasi-221002, IN
2 Pineal Research Laboratory, Department of Zoology, Banaras Hindu University, Varanasi-221005, IN

Abstract

The structure of Harderian gland (HG) of tropical avian species has never been studied in detail. In the present study we investigated the structure of HG of a t ropical avian species adopting light- and transmission electron microscopy. HG from both male and female adult birds, P. asiatica (N=5 each sex) were studied from light microscopic (hematoxylin-eosin staining) and transmission electron microscopic perspectives. The tubulo-alveolar HG of P. asiatica did not reveal any sexual dimorphism as reported in other birds. The HG of this bird is encapsulated by thick connective tissue consisting of collagen fibers, nerve fibers and blood vessels. HG lobules are lined with columnar epithelial cells. Plasma cells are found in interlobular spaces. The columnar epithelial cells are secretory in nature and have both rough and smooth endoplasmic reticula surrounding the nucleus when observed in transmission electron microscope. There is active Golgi apparatus with dilated cisternae. Mitochondria are well developed, with elongated cristae, and are scattered throughout the cytoplasm along with abundant free ribosomes. Lipid droplets are present in the cytoplasm along with two types of materials, electron-luscent and electron-dense. We could trace the various stages of synthesis of the secretory material for merocrine release. Thus, the light microscopic and ultrastructural organization of HG of P. asiatica have been elucidated.

Keywords

Bird, Indian Jungle Bush Quail, Harderian Gland, Secretory Acini.

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Rakesh Verma ¹, Sriparna Pal ¹, Jitendra Kumar ¹, Chandana Haldar ¹

Affiliations
1 Department of Zoology, Banaras Hindu University, Varanasi – 221005, Uttar Pradesh, IN

Abstract

Ultraviolet radiation is causative of generation of reactive oxygen species (ROS) in the body that significantly affects normal physiology and disturbs homeostasis. In the present study we investigated the effect of UV-A radiation exposure on the first line of defence system such as skin and vital organs such as liver, kidney and spleen of Rattus norvegicus. Adult female rats were exposed to UV-A radiation for seven days at a dose of 6.36 J/cm² and the changes in the skin histoarchitecture, oxidative load of spleen, liver and kidney along with cellular ROS levels of splenocyte determined using DCFDA staining were recorded. UV-A exposure severely damaged the histoarchitecture of skin and reduced proliferating cell nuclear antigen (PCNA) expression. The lipid peroxidation (MDA) level in spleen, liver and kidney were increased to significant levels while the activities of the enzymatic antioxidants, SOD and catalase were significantly decreased. Significant decrease of glucose content and increase of LDH of both spleen and liver were found. Cellular damage of splenocyte was observed as evidenced by increase in percentage of intense DCFDA-stained cells in UV-A treated rats. Thus, our results clearly demonstrate that UV-A radiation exposure may have detrimental effects on the antioxidant defence system of the body, including melatonin, leading to disruption of physiology by affecting vital organs.

Keywords

Kidney, Liver, Oxidative Stress; Skin, Spleen, Splenocyte, DCFDA, PCNA, UV-A Radiation.

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