The present study investigates the testicular and adrenocortical activities under different doses and durations of chromium (Cr) exposure and their interactions. Mature male Sprague Dawley rats were injected daily with three different doses (0.2, 0.4, and 0.6 mg/kg bw) of Cr salt (K2Cr2O7) intraperitonealy for 13 and 26 days, respectively. The medium (0.4 mg/kg bw/day) and higher dose (0.6 mg/kg bw/day) of Cr significantly (p &lt; 0.05) decrease accessory sex organs weight, testicular Δ53β-hydroxysteroid dehydrogenase (HSD) and 17β-HSD activities, epididymal sperm count, effective spermatid degeneration, serum testosterone, LH level, testicular catalase and superoxide dismutase (SOD) activities while testicular lipid peroxidation, serum FSH, corticosterone level, adrenal weight and adrenal Δ53β-HSD activity increased significantly than that of control and lower dose (0.2 mg/kg bw/day) Cr exposed animals. Testicular histoarchitechture shows deterioration after critical dose (0.4 mg/kg bw/day) and duration (26 days) of Cr exposure. Cr induced alterations on testicular and adrenocortical activities are dose and duration dependent. Adrecortical hyperactivity accompanied by testicular oxidative stress might have a crucial role for Cr induced male reproductive impairment. © 2007 Elsevier Inc. All rights reserved.

A K CHANDRA

A CHATTERJEE

R GHOSH

M SARKAR

S K CHAUBE

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Reproductive Toxicology

Iodine consumption in excess of its recommended levels over a prolonged period of time is well known to cause thyroid disorders. The thyroid hormones on the other hand are responsible in maintenance of the physiology of the reproductive system. Excess iodine intake affects male reproductive physiology. However, the effects of excess iodine on the ovarian structure and function is yet to be established. The present study has thus been undertaken to investigate the effect of excess iodine on the ovarian physiology. Excess iodine was administered through oral gavage in the form of potassium iodide (KI) for duration of 60 days, at two different doses. The doses used were 100 EI, i.e., 100 times more than the recommended level but tolerable to the thyroid gland and 500 EI, i.e., 500 times more than the recommended level that altered thyroid physiology. The animals were divided into three groups, one control group, and the other two receiving two separate doses (100 EI and 500 EI) of excess KI. Estrous cyclical changes, ovarian morphological changes, ovarian iodine accumulation and ovarian steroidogenic enzyme activities were analysed. The thyroid functional status was studied from the serum thyroid hormones levels. The overall results revealed a biphasic action of excess iodine that depends on its dose. At 100 EI, excess iodine did not alter thyroid physiology but lead to the development of a hypoestrogenic state. There was an increased accumulation of iodine in the ovary with decreased activity of ovarian steroidogenic enzymes and lowered serum estradiol levels. However, at 500 EI, excess iodine developed a hyperthyroid condition, which further leads to a hyperestrogenic state. There was an increased activity of serum steroidogenic enzymes as well as elevated serum estradiol levels. Fertility index was zero in both the 100 EI and 500 EI treated groups of experimental animals. Thus excess iodine (100 EI) ingestion within tolerable range though maintained a euthyroid condition yet developed a state of hypofunctioning ovary. Conversely, excessive iodine (500 EI) is intolerable to thyroid, develops a hyperthyroid condition that leads to a hyperfunctioning ovary. Therefore prolonged exposure of iodine in excess exerts biphasic mode of action depending on the dose in female reproductive physiology and both the doses used in this study affected fertility equally. © 2016 Elsevier GmbH

Journal of Trace Elements in Medicine and Biology

Biphasic action of iodine in excess at different doses on ovary in adult rats

Improper iodine intake is a major concern in public health. Chronic intake of low iodine affects gonadal functions of man and animals; however, such effects of excess iodine in male reproduction, specially on testicular morphology, testicular steroidogenic enzyme activities, sperm morphology, sperm viability, and sperm count including male hormonal profiles in reference to iodine status and thyroid hormone profiles are yet to be explored. With this background, adult male rats of 120 ± 10 gm Bw of 90 ± 5 days were divided broadly in two groups depending on the duration of the treatment for 30 and 60 days, respectively. Both the groups consisted of control animals. Excess iodine (100EI), i.e., 100 times more than its recommended level but within its tolerable ranges, was administered through gavage regularly to the first group of experimental animals for 30 and 60 days, respectively, and excessive iodine (500EI), i.e., 500 times more than its recommended level and above tolerable range in the same way and for the same durations, was administered to the other group of experimental animals. Overall results revealed that regular consumption of iodine in excess impairs reproductive functions in adult male rats depending on the dose and duration of its exposure through different mechanisms. Excess iodine accumulates in the testis which results in generation of reactive oxygen species (ROS) as evidenced by higher lipid peroxidation level as well as an imbalance in the pro-/antioxidant status inhibiting the activity of ∆ 5 3β- hydroxysteroid dehydrogenase (HSD) and 17β-HSD resulting to reduced synthesis of testosterone that causes structural and functional changes of the testis. Secondly, persistent generation of ROS in testis as a result of prolonged excess iodine exposure affects hypothalamo–pituitary–adrenal axis that stimulates synthesis and secretion of corticosterone which inhibits LH release that downregulates testosterone synthesis causing further testicular disruption. Thirdly, excess iodine when administered above its tolerable ranges for prolonged duration acts on thyroid itself developing a state of biochemical hypothyroidism (as evident by low T3) which further potentiate the disrupting effect of excess iodine on male gonads by reducing circulating testosterone level. © 2015, Springer Science+Business Media New York.

Biological Trace Element Research

Effect of Excess Iodine on Oxidative Stress Markers, Steroidogenicâ€”Enzyme Activities, Testicular Morphology, and Functions in Adult Male Rats

Calcium is essential for functioning of different systems including male reproduction. However, it has also been reported as chemo-castrative agent. The study has been undertaken to elucidate the effect of excessive dietary calcium on male reproductive system in animals with possible action. Adult male healthy rats fed CaCl2 at different doses (0.5, 1.0 and 1.5 g%) in diet for 13 and 26 days to investigate reproductive parameters as well as the markers of oxidative stress. Significant alteration was found (P&lt;0.05) in testicular and accessory sex organs weight, epididymal sperm count, testicular steroidogenic enzyme (Δ5 3β-HSD and 17β-HSD) activities, serum testosterone, LH, FSH, LPO, activities of antioxidant enzymes, testicular histoarchitecture along with adrenal Δ5 3β-HSD activity with corticosterone level in dose- and time-dependent manner. Overall observations suggest that excessive dietary calcium enhances the generation of freeradicals resulting in structural and functional disruption of male reproduction. © Springer Science+Business Media, LLC. 2011.

Molecular and Cellular Biochemistry

Excessive dietary calcium in the disruption of structural and functional status of adult male reproductive system in rat with possible mechanism

Excess chromium (Cr) exposure is associated with various pathological conditions including reproductive dysfunction. Generation of oxidative stress is one of the plausible mechanisms behind Cr induced cellular deteriorations. The efficacy of vitamin E to combat Cr induced oxidative damage in adult rat testis has investigated in the current study. Adult male rats exposed to hexavalent Cr (intraperitoneal injection with 0.4 mg K2Cr2O7/kg bw/day) for 26 days resulted in decreased accessory sex organs weight compared to controls. Development of oxidative stress in testis was evidenced by increased lipid peroxidation along with decreased superoxide dismutase (SOD) and catalase activities than control animals. Marked reduction in the activities of testicular steroidogenic enzymes; Δ53β-hydroxysteroid dehydrogenase (HSD), 17β-HSD, serum testosterone and Leutinizing Hormone (LH) levels were observed. However significant increase in serum Follicle Stimulating Hormone (FSH) level was observed with Cr treated group. Histological evaluation of testis revealed degeneration of stage VII spermatogenic cycle along with decrease in epithelial cell height in epididymis and seminiferous tubules; number of different germ cells per seminiferous tubule and seminiferous tubular diameter reduced after Cr exposure. Simultaneous oral supplementation of vitamin E (50 mg/kg bw/day) in Cr exposed rats showed less oxidative damage and restored the otherwise altered testicular activities. Epididymal sperm number was also restored in vitamin E-supplemented group than Cr induced rats. This study implicates vitamin E as a possible protective agent against Cr induced spermatogenic and steroidogenic alteration. © 2010 Elsevier Ltd. All rights reserved.

Food and Chemical Toxicology

Vitamin E-supplementation protect chromium (VI)-induced spermatogenic and steroidogenic disorders in testicular tissues of rats

Cassava (Manihot esculenta Crantz), a widely used common vegetable of Indian origin contains dietary goitrogens. Goitrogenic content, in vitro anti-thyroidal activity and in vivo antithyroid potential of fresh and cooked cassava of Indian origin in albino rats with and without iodine supplementation were evaluated in this study. In vitro inhibition of thyroid peroxidase (TPO)activity was found with fresh and cooked cassava extract but the presence of extra iodide in the incubation media had shown reduction in such inhibition to an extent. Inhibition constant (IC50) and PTU equivalence of fresh cassava were 42.5 ± 1.35μg and 2.21 respectively. After consumption, cyanogenic constituents in cassava are metabolized to thiocyanate and iodine-retaining capacity seems to be dependent on thiocyanate exposure. In cassava fed rats, the urinary iodine concentration resembled the state of adequate iodine nutriture but thyroid gland fails to utilize available iodine. Increased thyroid weight (P &lt; 0.001), inhibited thyroid peroxidase (TPO) activity and reduced thyroid hormone profiles (P &lt; 0.001) were noted in fresh and cooked cassava fed rats, resembling a relative state of morphological as well as biochemical hypothyroidism even in presence of adequate iodine. © Copyright 2006 - African Journal Tradional, Complementary and Alternative Medicines.

Fulltext

African Journal of Traditional, Complementary and Alternative Medicines

Effect of cassava (Manihot esculenta Crentz) on thyroid status under conditions of varying iodine intake in rats

Methods of Biochemical Analysis

Fluorimetric Analysis of Corticoids

Human Reproduction

Chronic chromium exposure-induced changes in testicular histoarchitecture are associated with oxidative stress: study in a non-human primate (Macaca radiata Geoffroy)

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ISSN	0890-6238