Certain epidemiological studies revealed correlation between hardwater consumption (with high calcium) and thyroid size of the population, though the possible alterations in thyroid physiology upon calcium exposure are still inconclusive. Adult maleWistar strain rats were subjected to calcium treatment at the doses of 0.5 g%, 1.0g% and 1.5g% calcium chloride (CaCl2) for 60 days. The parameters studied were - thyroid gland weight, histopathology, histomorphometry; thyroid peroxidase (TPO), 5'-deiodinase I (DI), sodium-potassium adenosine triphosphatase (Na +-K+-ATPase) activities; serum total and free thyroxine (tT4, fT4), total and free triiodothyronine (tT3, fT3), thyroid stimulating hormone (TSH) levels. Enlargement of thyroid with hypertrophic and hyperplastic changes, retarded TPO and 5'-DI but enhanced Na+-K+-ATPase activities, augmented serum total and free T4 and TSH but decreased total and free T3 levels and low T3/T4 ratio (T3:T4) were observed in the treated groups. All these findings indicate development of goitrogenesis upon exposure to excessive dietary calcium. © 2012 Elsevier B.V. All rights reserved.

A K CHANDRA

H GOSWAMI

P SENGUPTA

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

Environmental Toxicology and Pharmacology

This review comprehensively summarizes the effects of more than 15 mostly used pesticides on male reproductive physiology, as recent experimental and epidemiological research have indicated their alarming impact on overall human health. Mechanisms have described that pesticide exposure damages spermatozoa, alter Sertoli or Leydig cell function, both in vitro and in vivo and thus affects semen quality. But, the literature suggests a need for more intricate research in those pesticides that are defined as mutagens or carcinogens and directly affect the hypothalamic-pituitary-gonadal axis. This literature review also proposes specific solutions to overcome these health effects.

Human and Experimental Toxicology

Environmental toxins: Alarming impacts of pesticides on male fertility

This review summarizes the effects of more than 20 metals that, research has indicated, may influence male reproductive health. Though males lack an apparent, easily measurable reproductive cycle, progress has been made in evaluating tests to identify chemical hazards and estimate reproductive health risks. Some agents discussed in this review are well known to have potential toxic effects on the male reproductive system, whereas some are not so well established in toxicology. This review attempts to cover most of the known toxicants and their effects on male fertility. The literature suggests a need for further research in those chemicals that are reactive and capable of covalent interactions in biological systems, as well as those defined as mutagens and/or carcinogens, to cause aneuploidy or other chromosomal aberrations, affect sperm motility in vitro, share hormonal activity or affect hormone action, and those that act directly or indirectly to affect the hypothalamo-pituitary-gonadal axis. © 2013 Informa Healthcare USA, Inc.

Drug and Chemical Toxicology

Environmental and occupational exposure of metals and their role in male reproductive functions

Background: Experimental unilateral cryptorchidism (ULC) and bilateral cryptorchidism (BLC) are excellent methods to study undescended testis in relation to spermatogenesis against a temperature gradient. Objectives: In case of ULC, it is possible to compare the testicular functions between normal condition and cryptorchidism in the same animal, whereas BLC shows the necessity of testicular androgens for proper maintenance of reproductive structures and functions. Materials and Methods: In the present study, experimental ULC and BLC was done on same-aged adult mature male mice and kept for 15 days and 30 days, respectively, to observe the changes due to the induced cryptorchidism on the different reproductive organs, viz., the testis and accessory sex organs along with epididymal sperm count. Reproductive tissues were collected from individual animals and histopathological studies of testis were done to investigate different cytological changes. Results: The size of the testes and accessory sex organs were found to be significantly reduced in BLC mice, whereas only testicular weight reduction was observed in ULC mice. Histopathological studies showed degenerative changes throughout the seminiferous tubules. Conclusion: Thus, the present investigation showed compensatory androgen production in ULC mice, whereas absence of androgen mediated reproductive functions in BLC animals.

Fulltext

Journal of Human Reproductive Sciences

Unilateral and bilateral cryptorchidism and its effect on the testicular morphology, histology, accessory sex organs, and sperm count in laboratory mice

Life Sciences

Maintenance of brain thyroid hormone level during peripheral hypothyroid condition in adult rat

Archives of Biochemistry and Biophysics

Structural and functional aspects of thyroid peroxidase

Endocrinology

Role of Calcium-Calmodulin-Dependent Protein Kinase Cascade in Thyrotropin (TSH)-Releasing Hormone Induction of TSH and Prolactin Gene Expression

Journal of Biological Chemistry

Transcriptional Repressor DREAM Interacts with Thyroid Transcription Factor-1 and Regulates Thyroglobulin Gene Expression

Current Opinion in Pediatrics

Thyroid hormone deiodinases: physiology and clinical disorders

Dietary calcium induced cytological and biochemical changes in thyroid

Journal	Data powered by TypesetEnvironmental Toxicology and Pharmacology
Publisher	Data powered by TypesetElsevier B.V.
ISSN	1382-6689