Journal of Endocrinology and Reproduction

Govindarajulu, P.

• Genetics of Medullary Thyroid Carcinoma

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Authors

M. Michael Aruldhas ¹, N. Kalpana ¹, G. Vengatesh ¹, K. Sakhila Banu ², P. Govindarajulu ¹

Affiliations
1 Department of Endocrinology, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai-600113, IN
2 Ontogenie et Reproduction, CRBR, CHUL, 2705 Boul W Lauira, Laval University Stc Roy, que, GIV 4G2, CA

Source

Journal of Endocrinology and Reproduction, Vol 5, No 1&2 (2001), Pagination: 59-76

Abstract

Existing modes of diagnosis and therapy for medullary thyroid carcinoma (MTC) have limitations, informations on the genetics of familial medullary thyroid carcinoma (FMTC), a constituent of multiple endocrine neoplasia II (MEN II) syndrome may help to understand the etiology of the disease and to design gene therapy. Association between specific mutations in ret protooncogene to specific phenotypes of MEN II subjects provide vital line of due for the diagnosis of the disease. Screening of suspected/potent carriers of ret (rearranged during transformation) mutations will help to decide about the time and course of treatment. Gene therapy for MTC appears to be imminent and this review attempts to provide a comprehensive account of informations from more than hundred research articles published in this area.

Keywords

Calcitonin, Familial Medullary Thyrold Carcinoma, Gene Therapy, Immuno Therapy, Medullary Thyroid Carcinoma, Multiple Endocrine Neoplasia, Ret Protooncogene.

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• 4(R)-5, 10, Seco 19-Norpregna 4,5 Diene 3, 10, 20 Trione (Seco), an Inhibitor of Epididymal 5α-Reductase Arrests Sperm Forward Motility in Wistar Rats

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Authors

M. Michael Aruldhas ¹, G. Rajendiran ¹, S. Subramanian ¹, S. Dharmalingam ¹, P. Govindarajulu ¹

Affiliations
1 Department of Endocrinology, Dr. ALM. PG. Institute of Basic Medical Sciences, University of Madras, Taramani, Chennai - 600 113, IN

Source

Journal of Endocrinology and Reproduction, Vol 3, No 1&2 (1999), Pagination: 95-111

Abstract

The effect of 4(R) - 5, 10, Seco 19 - norpregna 4,5 diene 3,10, 20 trione (SECO), a potent inhibitor of 5α-reductase, an intracellular enzyme that converts testosterone to dihydrotestosterone (DHT), on epididymal sperm count and motility was studied in Wistar rats. Administration of (i.m.) 250, 500, 750,1000 μg SECO/Kg b.wt/day to mature rats for 45 days impaired sperm forward motility in a dose dependent manner. Epididymal weight and sperm number decreased in rats treated with 750 and 1000 μg SECO, whereas weight of other accessory organs decreased in rats treated with 1000 μg SECO only. The epididymal histology showed degraded sperm and increased number of clear cells indicating high endocytotic activity, to clear dead sperm, whereas no obvious change was observed in the testicular histology. SECO treatment increased testosterone concentration whereas, it decreased estradiol concentration in circulation and in the epididymal tissue. SECO treatment specifically decreased 5α-reductase in epididymis without affecting the same in the liver, indicating its targeted effect on the epididymis. Thus, the preliminary in vivo study points out that SECO impairs the acquisition of sperm forward motility.

Keywords

Epididymis, 5α-Reductase Inhibitor, SECO, Sperm Fordward Motility.

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• Transient Gestational Hypothyroidism-Induced Changes in the Pituitary Testicular Axis Differ from that of Neonatal Onset Hypothyroidism

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Authors

A. M. J. Sashi ¹, N. S. Venkatesh ¹, P. Sekhar ¹, J. Anbalagan ¹, G. Vengatesh ¹, P. Govindarajulu ¹, M. M. Aruldhas ¹

Affiliations
1 Department of Endocrinology, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai 600 113, IN

Source

Journal of Endocrinology and Reproduction, Vol 7, No 1&2 (2003), Pagination: 42-42

Abstract

Hypogonadism and male infertility associated with congenital hypothyroidism are two important reproductive health problems. Studies emanated from our laboratory and a few others have established thyroid hormone as an important regulator of testicular development, growth, structure and function. Existing literature are centering around the effect of neonatal, prepuberal and puberal onset hypothyroidism on the testis of adult rats.

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• Effects of Experimental Diabetes and Insulin Replacement on Testicular Leydig Cells of Adult Rat

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Authors

S. Yuvaraj ¹, C. Parthasarathy ¹, N. Srinivasan ¹, P. Govindarajulu ¹, K. Balasubramanian ¹

Affiliations
1 Department of Endocrinology, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai 600 113, IN

Source

Journal of Endocrinology and Reproduction, Vol 7, No 1&2 (2003), Pagination: 44-45

Abstract

Clinical and experimental studies have shown the adverse effects of diabetes on testicular steroidogenesis and spermatogenesis. The present study was designed to assess the effects of streptozotocin (STZ)-diabetes on Leydig cell LH receptors and steroidogenic enzymes. Diabetes was induced by single intraperitoneal injection of STZ at a dose of 65 mg/kg body weight. Induction of diabetes was confirmed by plasma insulin and glucose estimations. One set of diabetic rats was treated with insulin (3U/100g body weight/day in two equally divided doses), 3 days after STZ treatment. Control and experimental animals were killed after twenty days.

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• Dose-Dependent Effects of Corticosterone on Leydig Cell LH Receptors and Steroidogenesis In vitro

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Authors

S. Rengarajan ¹, R. Sivakumar ¹, N. Srinivasan ¹, P. Govindarajulu ¹, K. Balasubramanian ¹

Affiliations
1 Department of Endocrinology, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai-600 113, IN

Source

Journal of Endocrinology and Reproduction, Vol 7, No 1&2 (2003), Pagination: 54-55

Abstract

Glucocorticoid excess due to stress, endocrine disorders or therapeutic application has been recognized to have an adverse efTect on androgenic status of men. Our previous studies emphasized the defective LH signal transduction in Leydig cells exposed to corticosterone. The present study was designed to identify the dose-dependent effects of corticosterone on the regulation of Leydig cell surface LH receptors and steroidogenic potency in vitro.

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• Dose Dependent Effects of Gamma Radiation on LH and cAMP Stimulated Steroidogenesis in Cultured Human Leydig Cells

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Authors

R. Sivakumar ¹, J. Arunakaran ¹, N. Srinivasan ¹, P. Govindarajulu ¹, K. Balasubramanian ¹

Affiliations
1 Department of Endocrinology, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai-600 113, IN

Source

Journal of Endocrinology and Reproduction, Vol 7, No 1&2 (2003), Pagination: 55-55

Abstract

Therapeutic or experimental radiation exposure is known to impair testicular Leydig cell function. However, the molecular mechanisms that underlie such effects are largely unknown. Our previous study demonstrated that higher doses of gamma radiation impair basal and LH-stimulated cAMP production. The present study deals with the dose dependent effects of gamma radiation on LH and cAMP stimulated steroidogenesis in human Leydig cells. Testicles removed from advanced prostatic carcinoma patients, who do not have any endocrine or metabolic disorders known to affect the testicular functions were used in the present study. Prior to orchidectomy, serum hormones such as FSH, LH, testosterone and estradiol were assayed to evaluate the testicular functions.

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• Effect of 17β-Estradiol (E₂) on the Production of Insulin Like Growth Factor-I (IGF-I) and their Components on PC-3 Cell Lines

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Authors

P. Kanagaraj ¹, M. R. Vijayababu ¹, S. Sitta-Djody ¹, N. Srinivasan ¹, M. M. Aruldhas ¹, P. Govindarajulu ¹, J. Arunakaran ¹

Affiliations
1 Department of Endocrinology, Dr. ALMPGIBMS, University of Madras, Taramani, Chennai - 600 113, IN

Source

Journal of Endocrinology and Reproduction, Vol 7, No 1&2 (2003), Pagination: 56-56

Abstract

Insulin like growth factors have been implicated in the regulation of prostate epithelial cell proliferation and induction of prostate cancer. Estrogens play an important role in prostate physiology and disease development. E₂ has been reported to regulate the production of IGFs and IGFBPs in prostate cell lines. Hence, it is attempted to study the effects of E₂ on the production of IGFs and IGFBPs in PC-3 cell line. The PC-3 cells (1x10⁵ cells/ well) were treated with different doses of E₂ (1,10 and 10 nM) for 24 hrs and 48 hrs, the conditioned media were collected and assayed for IGF-I and IGFBP-5. Dose and duration dependent effect of E₂ on IGF-I and IGFBP-5 on PC-3 eel lines will be discussed with available literature.

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• Gestational Exposure to Chromium Alters the Histoarchitecture of Adult Rat Testis: a Light Microscopic Study

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Authors

P. Sekhar ¹, S. Subramanian ², N. S. Venkatesh ², A. M. J. Sashi ², N. Kalpana ², J. Anbalagan ², G. Vengatesh ², P. Govindarajulu ², M. A. Akbarsha ³, M. M. Aruldhas ²

Affiliations
1 Post Graduate Department of Zoology, Voorhees College, Vellore-632001, IN
2 Department of Endocrinology, University of Madras, Dr. ALM Post Graduate Institute of Basic Medical Sciences, Taramani Campus, Chennai-600113, IN
3 Department of Animal Science, Bharathidasan University, Tiruchirappalli-620024, IN

Source

Journal of Endocrinology and Reproduction, Vol 7, No 1&2 (2003), Pagination: 86-87

Abstract

Heavy metals and chemicals are known to cause male infertility. Chromium, an occupational heavy metal pollutant is a wellknown carcinogen with toxic effect on skin, lung and kidney. A few early reports point out the reproductive toxicity of chromium in experimental animals. An extensive study conducted in our laboratory in adult rats and monkeys established that altered prooxidant - antioxidant balance leading to free radical toxicity in the testis as the mechanism underlying the reproductive toxicity of chromium.

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• Gestational Exposure to Chromium Interferes with Post-Natal Development and Growth of the Thyroid Gland through Altered TSH

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Authors

A. Jone Stanley ¹, M. Sabiha ¹, P. Sekhar ¹, S. Subramanian ¹, P. Govindarajulu ¹, M. M. Aruldhas ¹

Affiliations
1 Department of Endocrinology, University of Madras, Dr. ALM Post Graduate Institute of Basic Medical Sciences, Taramani Campus, Chennai-600113, IN

Source

Journal of Endocrinology and Reproduction, Vol 7, No 1&2 (2003), Pagination: 87-88

Abstract

Chromium is one of the important heavy metal toxicants released into the environment by about 50 industries, which includes leather tanneries, stainless steel welding, and ordinance factory and chrome platting. Though the adverse effect of chromium on skin, lung and reproductive organs are known, its toxic effect on endocrine glands is little known. It is well known that chromium can readily pass through the placental barriers to reach the growing foetus. Recent studies attest the embryo toxicity of gestational exposure to chromium. The thyroid is one of the earliest endocrine organs to develop from the endoderm and its development is regulated by specific transcription factor like TTF-1, TTF-2, Pax-8 and various other growth factors.

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• Effect of Polychlorinated Biphenyl (Aroclor 1254) on Rat Leydig Cellular Antioxidant System

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Authors

P. Murugesan ¹, J. Senthilkumar ¹, K. Balasubramanian ¹, M. M. Aruldhas ¹, P. Govindarajulu ¹, J. Arunakaran ¹

Affiliations
1 Department of Endocrinology, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani, Chennai-600 113, IN

Source

Journal of Endocrinology and Reproduction, Vol 7, No 1&2 (2003), Pagination: 91-92

Abstract

To find out the effect of polychlorinated biphenyl compound Aroclor 1254 on rat Leydig cellular antioxiSant system, adult male rats were exposed to Aroclor 1254 (2 mg/kg b.wt.) mixed with com oil through intraperitoneal (ip) injection daily for 30 days. The control rats were administered com oil as vehicle. Testes were removed on the both groups and Leydig cells were isolated by enzymatic digestion and purified on discontinous percoll gradient.

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• Transient Hypothyroidism during the Second Week of Gestation has a Temporal and Region Specific Effect on the Histoarchitecture of the Epididymis at Prepuberal, Puberal and Adult Rats

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Authors

A. M. J. Sashi ¹, N. S. Venkatesh ¹, G. Vengatesh ¹, P. Sekhar ¹, J. Anbalagan ¹, N. Kala ¹, P. Govindarajulu ¹, M. A. Akbarsha ², M. M. Aruldhas ¹

Affiliations
1 Department of Endocrinology, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai-600113, IN
2 Department of Animal Science, Bharathidasan University, Tiruchirappalli-620024, IN

Source

Journal of Endocrinology and Reproduction, Vol 7, No 1&2 (2003), Pagination: 75-75

Abstract

Recent demonstration of thyroid hormone receptors (TR) in epididymis by our laboratory and that of Del Rio point out that epididymis may also be a target for the direct effect of T₃. Recent studies emanating from our laboratory have shown the importance of foetal-onset hypothyroidism on the growth, structure and function of the epididymis in adult rats. Since there are temporal difference in the foetal differentiation of hypothalamo-hypophyseal-testicular axis and the differentiation of testis and epididymis, it is hypothesized "Transient maternal hypothyroidism modifies specific cell types of the epididymis during pre-puberal, puberal and adult period in a temporal manner".

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