Journal of Endocrinology and Reproduction

Sweta Arora ¹, Poonam Singh ¹, Priyoneel Basu ², Chandana Haldar ³

Affiliations
1 Mahila Mahavidyalaya, Banaras Hindu University, Varanasi 221005, IN
2 Behavioural Neuroscience Unit, Department of Psychology, University of Calgary, Calgary, Alberta, CA
3 Pineal Research Laboratory, Department of Zoology - Centre of Advanced Study, Banaras Hindu University, Varanasi 221005, IN

Abstract

Different thresholds of gonadal steroids exert stimulatory or inhibitory effects on GnRH and gonadotropin release. During the reproductively active phase (RAP), the concentration of endogenous gonadal steroids remains high while, during reproductively inactive phase (RIP), it remains low. During RIP the HPG axis is sensitive to gonadal steroids but the circulatory levels of testosterone and estradiol remain low. During this phase one can observe conveniently the effects of gonadal steroids on the HPG axis in male or female rodents. Therefore, the aim of the present study was to find the effects of testosterone and estradiol on the reproductive functions of male and female Indian pygmy field mouse, Mus terricolor, during RIP. The male mice were injected aquaviron (commercially available testosterone, 1mg/100g body weight) while the female mice received estradiol-benzoate (25μg/100g body weight) for 15 consecutive days during the RIP. After completion of the treatment, a significant increase in the weights of gonads and accessory sex organs was noted in both the sexes. The biochemical constituents of accessory sex organs such as epididymal sialic acid, seminal vesicular fructose and uterine protein content reflected significant elevation accompanied by increased levels of plasma testosterone, estradiol and progesterone. Histologically, the gonads and accessory sex organs exhibited increased cellular activity. However, the gonadal cholesterol was significantly decreased in both the sexes. Over all, administration of gonadal steroids to both male and female mice accelerated the gonadal recrudescence but did not inhibit the reproductive functions when administered during the RIP. Therefore, it can be inferred from the present study that during the RIP the HPG axis is sensitive to gonadal steroids and, hence, exogenous gonadal steroids induce gonadal activity.

Keywords

Gonadal Steroids, Mus terricolor, Reproduction, Tropical Rodent, Seasonal Breeder.

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Sweta Arora ¹, Poonam Singh ¹, Chandana Haldar ²

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

Abstract

Inhibitory effects of glucocorticoids have been reported in a number of species ranging from rodents to humans. No report till date exists demonstrating the effect of stress on reproduction in Mus terricolor, a tropical, wild, nocturnal, short day breeder. To replicate stress-like situation under experimental condition, dexamethasone (60μg/ 100g body weight) treatment was given to female M. terricolor during the reproductively active phase (RAP) of its breeding cycle. Suppressive effect of dexamethasone on reproductive functions of this tropical nocturnal rodent was inferred. There was a significant reduction in ovarian and uterine weight, which was accompanied by a significant reduction in uterine protein and plasma estradiol and progesterone levels while there was a significant increase in ovarian cholesterol. Histological observations revealed an inhibitory effect of dexamethasone on the reproductive tissues. The presence of glucocorticoid receptor in the ovary and uterus suggests that glucocorticoid might be directly involved in modulating reproductive functions of this rodent. Thus, exogenous glucocorticoid suppressed the reproductive function of this mouse suggesting a stressful condition.

Keywords

Glucocorticoid, M. terricolor, Reproduction, Stress, Tropical Rodent.

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Sweta Arora ¹, Poonam Singh ², Chandana Haldar ¹

Affiliations
1 Pineal Research Laboratory, Department of Zoology, Centre of Advanced Study, Banaras Hindu University, Varanasi – 221005, Uttar Pradesh, IN
2 Mahila Mahavidyalaya, Banaras Hindu University, Varanasi – 221005, Uttar Pradesh, IN

Abstract

The Indian pygmy field mouse, Mus terricolor, a wild rodent has to face many stressors in the environment such as unpredictable harsh weather, non-static habitats, food shortage, water scarcity, social pressure, risk of predators and parasites, etc. Glucocorticoids are known to suppress reproductive functions during the stressful situations in many rodents. No report till date exists demonstrating the effects of stress on the reproduction in male M. terricolor, a tropical, wild, nocturnal, short day breeder. To replicate stress-like situation under experimental condition, dexamethasone (60μg/100g body weight) treatment was given to this tiny rodent during the Reproductively Active Phase (RAP) of its breeding cycle. Administration of dexamethasone led to significant reductions in the weights of gonad and accessory sex organs, which were accompanied by significant reductions in the biochemical constituents viz epididymal sialic acid and seminal vesicular fructose. The levels of plasma testosterone also decreased significantly while there was a significant increase in the gonadal cholesterol after the treatment. Histological observations revealed inhibitory effects of dexamethasone on the reproductive tissues. It is therefore, suggested that the stressful condition due to exogenous administration of glucocorticoid suppressed the reproductive functions of M. terricolor.

Keywords

Glucocorticoid, M. terricolor, Reproduction, Stress, Tropical Rodent.

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Sweta Arora ¹, Rajesh Yadav ², Chandana Haldar ¹

Affiliations
1 Pineal Research Lab, Department of Zoology, Banaras Hindu University, Varanasi, Varanasi - 221005, Uttar Pradesh, IN
2 Dr. Bhim Rao Ambedkar Government Degree College, Dhaneva Dhanei, Maharajganj, Uttar Pradesh, IN

Abstract

Pregnancy is associated with profound immunological changes that are characterized by a strong activation of certain components of the innate immune defense and a down-regulation of adaptive immune functions. This shift in balance of the immune system towards an innate dominance is thought to be important for the maintenance of pregnancy. Based on our observation in the short nosed fruit bat Cynopterus sphinx, a seasonal breeder, we show for the first time that melatonin injection to the pregnant females significantly increases lymphocyte proliferation of spleen and consequently the circulating level of lymphocytes and percent stimulation ratio of splenocytes, thereby improving immune status during pregnancy. We have reported earlier that during pregnancy melatonin level increases significantly which in turn might improve the maternal immunity. Towards establishing this inference we used a physiological dose of p-chlorophenylalanine (p-CPA), an indirect antagonist of melatonin, which reduced circulatory melatonin level and thereby reduced the immune status. It is conceived that specific immune adaptation is conveyed to the fetus through placental transfer of melatonin thereby controlling fetal immunity as well. This could be an adaptation during pregnancy to protect the mother from various external threats.

Keywords

Cynopterus Sphinx, Immunity, Melatonin, Pregnancy.

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Sweta Arora ¹, Ratna Sarkar ¹, Chandana Haldar ¹

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

Abstract

The investigation of pineal-specific proteins is not new but offers scope for identification of antigonadotropic compound(s). There is difference in the activities of the reproductively active and inactive phase pineal homogenates of seasonally breeding animals, e.g., squirrels. The present study aimed at checking the squirrel pineal proteins adopting gel-electrophoresis technique. Homogenate of the reproductively quiescent phase pineal homogenate separated into 14 fractions whereas that of reproductively active phase pineal presented 17 protein fractions (3 additional fractions). It is assumed that these three protein bands (which were not noted for the squirrel in reproductively inactive phase) are responsible for the antigonadal/ antigonadotropic effect of the pineal gland. The present study, though very preliminary in nature, has brought out the difference in the pattern of proteins of two different phases of the pineal gland- reproductively active and quiescent. The data throw open scope for extensive biochemical studies to decipher the physical and chemical nature and the properties of an anti-gonadotropic protein.

Keywords

Electrophoretic Separation, Pineal, Proteins.

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Sweta Arora ¹, Chandana Haldar ¹

Affiliations
1 Pineal Research Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi – 221005, Uttar Pradesh, IN

Abstract

The incidence of diabetes, a metabolic disorder, is increasing at a very rapid pace globally but hypoglycemic drugs like insulin, bioguanides, thiazolidiones and sulphonylureas, which produce several adverse side effects, are still the main stay for its treatment. However, the traditional medicines derived from plants have lesser side effects and are of low cost. Boerhaavia diffusa, belonging to Nyctaginaceae family, also known as Punarnava, has great many medicinal properties and is one of the oldest medicines described in Ayurveda for the treatment of a number of diseases including diabetes. B. diffusa has been reported to be diuretic, anti-inflammatory, anticonvulsant, antifibrolytic, antibacterial, antidiabetic, hepatoprotective, immunosuppressive, nephroprotective, antiasthamatic, antihelminitic, etc. It contains alkaloids, flavanoids, lipids, carbohydrates, steroids, lignins, proteins, triterpeniods, glycoproteins, β-sitosterol, α-2-sitosterol, ester of β-sitosterol, palmitic acid, β-ecdyosone, hexacosanoic, tetracosanoic, arachidonic and stearic acids, etc., which might be responsible for its curative properties. The present review focuses on the antidiabetic/hypoglycaemic property of this miracle plant.

Keywords

Antidiabetic, Boerhaavia diffusa, Diabetes, Hypoglycemic, Punarnava

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Sweta Arora ¹, Poonam Singh ¹, Priyoneel Basu ², Chandana Haldar ³

Affiliations
1 Mahila Mahavidyalaya, Banaras Hindu University, Varanasi – 221005, Uttar Pradesh, IN
2 Behavioural Neuroscience Unit, Department of Psychology, Banaras Hindu University, Varanasi – 221005, Uttar Pradesh, IN
3 Pineal Research Laboratory, Department of Zoology – Centre of Advanced Study, Banaras Hindu University, Varanasi – 221005, Uttar Pradesh, IN

Abstract

Testosterone, melatonin and glucocorticoids are known to mediate their actions through their respective receptors, i.e., Androgen Receptor (AR), Melatonin Receptor (MT1) and Glucocorticoid Receptor (GR), endowed on the target tissues. The gonads of M. terricolor responded positively to administration of these hormones, suggesting the possibility of a direct action of these hormones on the gonads through their respective receptors. The present study was, therefore, undertaken to localize the Androgen (AR), Melatonin (MT1) and Glucocorticoid (GR) receptors in the testis of this rodent adopting immunohistochemistry as the tool. The result indicated that AR is expressed in the Leydig cells and germ cells of the testis of M. terricolor. MT1 receptor is localized in the Leydig cells, peritubular myoid cells, and endothelial lining of blood vessels, all in the interstitial zone. The GR was localized in the nuclei of Leydig cells, macrophages and fibroblasts, and endothelial cells lining the blood vessels, all in the interstitium. The immunohistochemical localization of AR, MT1 and GR receptors in the testes of M. terricolor support the previous understanding that testis could be a target for the above-mentioned hormones in this rodent.

Keywords

Immunohistochemistry, Mus terricolor, Receptors, Seasonal Reproduction

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Sweta Arora ¹, Chandana Haldar ¹

Affiliations
1 Pineal Research Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi – 221005, Uttar Pradesh, IN

Abstract

Diabetes is a lifestyle disorder with multiple etiologies, one of them being damage induced by free radicals. Melatonin, a neurohormone secreted by the pineal gland, is a well-known antioxidant or free radical scavenger. The melatonin found in plants is known as phytomelatonin. Phytomelatonin is potent in regulating stress management, apoptosis, seasonality and circadian rhythms in animals as melatonin. The supplementation of phytomelatonin is known to potentiate the antioxidant capacity. Therefore, in the present study, we proposed that the supplementation of corn seed (Zea mays) with regular diet may modulate the activity of antioxidative enzymes in diabetic hamsters. The supplementation of diet with phytomelatoninrich corn did not reduce serum glucose level significantly. No significant elevation was noted in serum insulin level of animals after feeding corn. Glycogen level of both liver and muscle were also not significantly affected. However, phytomelatonin supplementation improved lipid profile by significantly reducing the cholesterol (TC) and LDL Cholesterol (LDL-C) and enhancing HDL Cholesterol (HDL-C). Significant reduction was noted in LPO level in pancreas. The supplemental diet led to significant increase in the level of Super Oxide Dismutase (SOD) and catalase (CAT) in pancreas. Diabetes produced a deleterious effect on oxidative stress markers, lipid profile, glucose, glycogen and insulin. Supplementation of corn in the diet for 40 days modified the biochemical parameters to various degrees. The phytomelatonin treatment improved most of the antioxidant parameters under investigation. The study has produced some positive outcomes, especially a strategy which may be relevant in prevention, development and/or slowing down of the progression of diabetes.

Keywords

Diabetes, Hamster, Melatonin, Phytomelatonin, Zea mays

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Chandana Haldar ¹, Sanjeev Kumar Yadav ¹, Sweta Arora ¹

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

Abstract

Photoperiod influences circulatory Melatonin (Mel) and hypothalamic functions via retino-hypothalamic tract. However, interrelation between Mel receptors and Arginine Vasotocin (AVT), a water-electrolyte balancing hormone receptor expression in hypothalamic regions of avian brain has never been explored. We noted the expression pattern of two Mel receptors (Mel1a & Mel1b) along with AVT, in terms of neuronal immuno-positivity, in hypothalamic region of Japanese quail under different photoperiodic conditions with/without melatonin treatment. This is interesting and equally important because both Mel and AVT levels are regulated by light/dark cycle. Confocal imaging revealed specific regional localization of Mel1a/Mel1b in Supra-Chiasmatic Nucleus (SCN), Supra-Optic Nucleus (SON) and Para-Ventricular Nucleus (PVN), the intensity of which was dependent on the photoperiodic condition (long day, LD or short day, SD) and melatonin treatment. Mel1a/Mel1b was mostly co-localized along with AVT. Mel1b was abundant in hypothalamic regions in contrast to the Mel1a as reported in mammals. Mel1a immune-positivity was detected in SCN and SON regions of brain. Compared to control birds, a high intensity of Mel1a immunoreactivity was found in hypothalamic regions of birds under short photoperiod (SD, 8h L: 16h D) after Mel treatment. Further, Mel1b immunopositivity was high only in birds exposed to long days (LD, 16h L: 8h D). In SCN, abundant Mel1a and AVT immunoreative cells were found in Mel pretreated and SDexposed birds compared to LD-exposed ones. Mel1a and AVT immunoreative cells were less in PVN of both SD and LD exposed birds. Our data of co-localization of Mel receptor(s) along with AVT in hypothalamic regions (exposed to short or long days with/without melatonin administration) strongly suggest a role for Mel along with AVT in water-electrolyte balance of birds which is important during long duration nuptial migration/flight.

Keywords

Co-Localization, Hypothalamus, Melatonin/AVT, Quail, Receptor, Water-Electrolyte Balance.

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Sweta Arora ¹, Sweta Arora ², Chandana Haldar ¹, Priyoneel Basu ³, Jasmeet Singh ², Sameer Gupta ¹

Affiliations
1 Pineal Research Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi – 221005, Uttar Pradesh, India ., IN
2 Department of Dravyagun, Institute of Medical Science, Banaras Hindu University, Varanasi – 221005, Uttar Pradesh, India ., IN
3 Kalinga Institute of Social Sciences-Deemed University, Bhubaneshwar – 751024, Odisha, India ., IN

Abstract

Diabetes, a common metabolic disorder, is affecting people irrespective of age group and/or gender. The chronic hyperglycemia during diabetes leads to heart-, kidney-, eye- and nerve damages. Boerhaavia diffusa, commonly known as Punarnava, is one of the traditional medicines described in Ayurveda for the treatment of a number of diseases. B. diffusa has been reported to exhibit antidiabetic, diuretic, anti-inflammatory, hepatoprotective, and immunomodulatory properties. The present study was carried out to evaluate the anti-hyperglycemic potential of ethanolic extract of root of B. diffusa and its effect on diabetes-induced kidney damage in hamster model. Treatment of ethanolic extract of B. diffusa resulted in significant reduction in the serum glucose level and increased insulin concentration with a simultaneous increment in the levels of muscle and liver glycogen. The oral supplementation of B. diffusa root extract improved lipid profile by reducing the cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and by increasing high density lipoprotein cholesterol (HDL-C). The activity of antioxidant enzymes Superoxide Dismutase (SOD) and Catalase (CAT) in the kidney significantly improved following oral administration of B. diffusa while a significant decrease in Lipid Peroxidation (LPO) level was noted in the kidney after the treatment. Ethanolic root extract of B. diffusa decreased the level of serum creatinine, urea and Alkaline Phosphatase (ALP) significantly. B. diffusa administration demonstrated marked improvement in renal histology as evident by the regenerative changes in glomerulus and Bowman’s capsule. Thus, the use of ethanolic extract of Boerhaavia diffusa may prove therapeutically effective in prevention as well as inhibition of the progression of diabetes and associated kidney damages.

Keywords

Boerhaavia diffusa, Diabetes, Diabetic Nephropathy, Hamsters, Punarnava

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Sweta Arora ¹, Poonam Singh ¹, Chandana Haldar ², Priyoneel Basu ³

Affiliations
1 Mahila Mahavidyalaya, Banaras Hindu University, Varanasi - 221005, Uttar Pradesh, IN
2 Pineal Research Laboratory, Department of Zoology - Centre of Advanced Study, Banaras Hindu University, Varanasi - 221005, Uttar Pradesh, IN
3 Kalinga Institute of Social Sciences Deemed to be University, Bhubaneswar - 751024, Odisha, IN

Abstract

Besides being potent regulators of energy balance, thyroid hormones are necessary for the maintenance of seasonal reproductive changes in many species of mammals and birds. The thyroid gland is known to be crucial for the seasonal transition in seasonal breeders from breeding to non-breeding. Many workers have reported that thyroid ablation prevents the animal from entering the non-breeding state in both males and females of different species of animals and, in such a situation, the breeding state is sustained indefinitely. No report exists to date about the involvement of the thyroid gland in the reproduction of the pygmy field mouse Mus terricolor. L-thyroxine was administered subcutaneously to both male and female mice for 15 consecutive days during the reproductively active phase. L-thyroxine treatment led to a significant reduction in the weights of gonads and accessory sex organs along with biochemical constituents like epididymal sialic acid, seminal vesicular fructose and uterine protein. Regressive changes in the histology of the gonads and accessory sex organs were observed which can be attributed to the reduced levels of plasma testosterone in males and plasma estradiol and progesterone in females of the L-thyroxine-treated mice. However, there was a significant increase in the levels of plasma T3, T4, and gonadal cholesterol in both sexes following L-thyroxine treatment. Both hypo- and hyper-thyroidism can influence gonadal activity. The observations in the present study suggest that hyperthyroidism leads to the transition of reproductively active gonads to inactivity substantiating the hypothesis that high levels of thyroxine can accelerate the reproductive inactivity in this rodent.

Keywords

Mus terricolor, Seasonal reproduction, Thyroid, Reproduction, Tropical rodent.

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