Scholarly Publications
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This community showcases the academic contributions of faculty and researchers at Banaras Hindu University (BHU) and provides a year-wise compilation of publications across disciplines. Institutional Repository BHU
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PublicationArticle Effects of hormones on the number, distribution and degranulation of mast cells in the ovarian complex of mice(1996) K. Jaiswal; Amitabh KrishnaThe changes in the number and degranulation pattern of mast cells varied with the types of hormonal treatment and ovarian compartment. Luteinizing hormone (LH), follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH) and 17-β estradiol (E2) treatment caused increase (P <0.05) in the number of mast cells in the hilum as compared with the controls. Increase (P <0.05) in the number of mast cells in the whole ovarian complex was observed only following FSH and E2 treatment. All the hormones used in the present study increased the percentage degranulation of mast cells in the hilum. However, only LH, FSH and E2 increased the percentage degranulation of mast cells in other compartments of the ovary (medulla, bursa and cortex). TSH and ACTH failed to cause any increase in the percentage degranulation of mast cells in these compartments. The present findings indicate E2 to be the most potent among the hormones tested in causing degranulation of mast cells in all ovarian compartments.PublicationArticle Occurrence of polyovular follicles and its possible significance in the ovary of the bat, Scotophilus heathi(1998) U.P. Singh; J. Doval; Amitabh KrishnaSeasonal changes in the number of polyovular follicles were estimated in a Vespertilionid bat, Scotophilus heathi. The largest number of polyovular follicles was observed during September, which coincided with the period of maximum development of intra-ovarian rete cells cord. It has been suggested that interaction between rete cells cord and follicle may be responsible for giving rise to a number of polyovular follicles in the medullary region of the ovary. Most of the polyovular follicles observed were biovular and they grow maximum up to the late preantral stage. Polyovular follicles with four or more oocytes were observed during September and they do not grow beyond stage I of the follicular development. The polyovular follicles were generally short lived and may contribute to the extensive development of the interstitial cells in S. heathi.PublicationArticle Immunolocalization of cytochrome P450 side chain cleavage, 17-α-hydroxylase and aromatase in the ovary of vespertilionid bat (Scotophilus heathi) during different phases of ovulatory delay(1998) Abhilasha; Amitabh KrishnaImmunocytochemical localization of steroidogenic enzymes, cytochrome P450 side chain cleavage, 17-α-hydoxylase and aromatase, was performed in the ovaries of Scotophilus heathi during reproductive cycle, with reference to the period of delayed ovulation. Moderate immunoreactivity of side chain cleavage enzyme and 17-α-hydroxylase was observed mainly in thecal cells and interstitial cells of the ovarian stroma during quiescence. Thecal cells positive for 17-α-hydroxylase were found even around the primary follicles. The peak immunoreactivity for all the three enzymes was observed during recrudescence. It coincided with high circulating steroid levels during this period. In the stroma, immunoreactivity for side chain cleavage and 17-α-hydroxylase was so extensive that it almost occupied the entire interfollicular area of the ovary. Aromatase imunoreactivity declined, by side chain cleavage enzyme and 17-α-hydroxylase remained extensive during the period of delayed ovulation. This suggests a high androgen and low estrogen synthesis during the period of delayed ovulation. There was a marked decline in 17-α-hydroxylase and an increase in aromatase immunoreactivity during the preovulatory period, suggesting a decrease in androgen and increase in estrogen synthesis. The results suggest thecal cells and interstitial cells of the stroma as the major site of steroidogenesis in the ovary of S. heathi. Over production of androgen is attributed to the extensive development of 17-α-hydroxylase positive interstitial cells in the ovarian stroma, and this may be responsible for delayed ovulation in Scotophilus heathi.PublicationArticle Unraveling the Mystery of Multi-Oocyte Follicles: An Observational Study(Societa Editrice Universo, 2024) C. Sahni; S. Seth; A.K. Nayak; R. SinghIntroduction. Significant progress has been made in understanding oocyte fertilization and early developmental stages through in vitro fertilization (IVF) techniques. However, irregularities such as conjoined oocytes and binucleate giant oocytes, which are exceptions to the normal rule of one diploid female gamete per follicle, can potentially lead to chromosomal disorders in embryos and are recommended to be excluded from IVF attempts. The formation of primordial follicles during ovarian development, known as follicle assembly, is a critical process that establishes the ovarian follicle reserve. Multi-oocyte follicles (MOFs) containing two or more oocytes have been observed in various species, including humans, and their clinical significance on fertility and reproductive health remains unclear. Genetic and environmental factors, such as gene knockout and exposure to endocrine disruptors, have been implicated in MOF formation, but the mechanisms are not fully understood and require further investigation. Material & Method. In this Observational study, 350 slides of ovarian tissues were scanned using an AI-based automated microscope, Grundium Ocus 20, and the TIFF images were stored in cloud storage. The slides were examined using third-party software, Pathcore Seeden Viewer, for morphometry of binovular follicles. Results. In our observational study, we examined 350 ovarian tissue slides in detail by using an AI-based microscope, uncovering 22 slides from seven different tissues with binovular and multinovular oocytes. These rare multi-oocyte follicles (MOFs) challenge the conventional one-oocyte-per-follicle paradigm. MOFs are likely formed when oocytes fail to separate during cortical sex cord proliferation, regulated by factors several molecular factorsas well as environmental factors. Discussion. Multiple Ovarian Follicles (MOFs) are rare phenomena where two or more oocytes exist in one follicle. They arise when oocytes fail to separate during ovarian development, which is governed by hormones such as follicle-stimulating hormone (FSH), inhibin, BMP-15, GDF-9, and GCNF. MOFs can be caused by dysregulation and exposure to chemicals such as diethylstilbestrol (DES) and isoflavones. Binovular oocytes, which occur when two oocytes are released during ovulation and are fertilised by different sperm, can result in non-identical twins, which are influenced by genetic and environmental factors such as maternal age, heredity, hormonal imbalances, and assisted reproductive techniques such as in vitro fertilisation (IVF). Polynuclear oocytes with many nuclei can develop as a result of meiotic spindle defects and environmental influences. Identifying these oocyte types may aid in improving ART results by improving knowledge of the reasons of infertility and devising appropriate interventions. Copyright © Società Editrice Universo (SEU)PublicationBook Chapter Hormones and reproductive cycles in bats(Elsevier, 2024) Amitabh Krishna; Vikas Kumar Roy; Arnab BanerjeeHighly diversified bats are shown to evolve numerous unusual reproductive specializations. Bats have a high basal metabolic rate, and energy produced is utilized mainly for flight. As a result, only limited energy is spared for reproduction. Majorities of bats are seasonal breeders due to insufficient availability of energy. Reproduction in temperate-zone bats initiated following arousal in spring coincides with the period of active food intake. Reproduction in these bats is suppressed during hibernation. Nonhibernating tropical bats show one or more breeding cycles, depending upon the availability of food. Temperate male bats exhibit a unique feature of reproductive asynchrony between spermatogenesis and functioning of accessory sex glands and libido because sufficient energy is not available to support both activities simultaneously. Many neotropical bats produce spermatozoa at a very high rate. Prolonged sperm retention in epididymis, prolonged lifespan, geographical variation in reproduction, and menstruation are some unusual features of the bat. Gonadal hormones together with metabolic hormones affect reproductive activities by regulating energy homeostasis. Female bats are unusually sensitive to environmental changes resulting in a variety of reproductive delays, such as delayed ovulation, sperm storage, delayed implantation, and development. The delays allow young to be born at an energetically favorable time. Detailed knowledge of the reproductive characteristics of this unique and ecologically important group of mammal is essential for their conservation. © 2024 Elsevier Inc. All rights reserved.PublicationArticle Cellular localization and seasonal variation of GnRH and Bradykinin in the ovary of Heteropneustes fossilis (Bloch.) during its reproductive cycle(Elsevier Inc., 2024) Padmasana Singh; Vrajesh Tripathi; Raj Kamal Srivastava; Amitabh KrishnaThe present study investigates the distribution and dynamics of gonadotropin-releasing hormone I (GnRH I) and bradykinin in the air-breathing catfish, Heteropneustes fossilis, in relation to the reproductive cycle. Changes in bradykinin, bradykinin B2-receptor, and ovarian GnRH I regulation were demonstrated during the reproductive cycle. The localization of GnRH I, bradykinin, and their respective receptors in the ovaries was investigated by immunohistochemistry, while their levels were quantified by slot/western blot followed by densitometry. GnRH I and its receptor were mainly localized in the cytoplasm of oocytes during the early previtellogenic phase. However, as the follicles grew larger, immunoreactivity was observed in the granulosa and theca cells of the late previtellogenic follicles. The ovaries showed significantly higher expression of GnRH I protein and its receptor during the early to mid-previtellogenic phase, suggesting their involvement in follicular development. Bradykinin and bradykinin B2-receptor showed a distribution pattern similar to that of GnRH I and its receptor. This study further suggested the possibility that bradykinin regulates GnRH I synthesis in the ovary. Thus, we show that the catfish ovary has a GnRH-bradykinin system and plays a role in follicular development and oocyte maturation in H. fossilis. © 2024PublicationArticle Adropin may regulate ovarian functions by improving antioxidant potential in adult mouse(Elsevier Ltd, 2024) Shweta Maurya; Shashank Tripathi; Taruna Arora; Ajit SinghThe corpus luteum (CL) is a temporary endocrine gland that synthesizes progesterone. The luteal progesterone plays a central role in the regulation of the estrous cycle as well as the implantation and maintenance of pregnancy. Our previous study showed the expression of adropin and its receptor, GPR19, in the luteal cells and its significant role in luteinization. The aim of the present study was to investigate the in vitro effect of adropin on hCG-induced ovarian functions in adult mice. We also evaluated the effect of exogenous treatment with adropin on ovarian steroidogenesis and anti-oxidant parameters, with special emphasis on CL function. Our results demonstrated that adropin acts synergistically with hCG to promote ovarian steroidogenesis and survival by increasing the expression of StAR, 3β-HSD, and aromatase proteins and decreasing the BAX/BCL2 ratio. Exogenous adropin treatment increased progesterone production by increasing the expression of GPR19, StAR and 3β-HSD enzymes in the mouse ovary. Also, adropin inhibited the luteal oxidative stress by increasing nuclear translocation of NRF-2 in CL, which resulted in increased HO-1 expression and SOD, catalase activity. Decreased oxidative stress might inhibit the translocation of NF-κB into the nucleus of luteal cells, resulting into increased survival and decreased apoptosis, as evident by decreased lipid peroxidation, BAX/BCL2 ratio, caspase 3, active caspase 3 expression, and TUNEL-positive cells in adropin treated mice. Our findings suggest that adropin can be a promising candidate that can enhance the survivability of the CL. © 2024 Elsevier LtdPublicationArticle Ontogeny of adropin and its receptor expression during postnatal development and its pro-gonadal role in the ovary of pre-pubertal mouse(Elsevier Ltd, 2023) Shweta Maurya; Shashank Tripathi; Ajit SinghAdropin, a highly conserved multifunctional peptide hormone, has a beneficial effect on the maintenance of gluco-lipid homeostasis, endothelial and cardiovascular functions. However, the expression and potential role of adropin in ovarian function are not fully elucidated. The present study aimed to investigate the expression of adropin and GPR19 in the mice ovary during various stages of postnatal development. This study also explored whether the treatment of adropin can modulate the timing of puberty, for which pre-pubertal mice were treated with adropin. The result showed the intense immunoreactivity of adropin in TICs, while GPR19 immunoreactivity was noted in GCs in infantile, pre-pubertal, and pubertal mice ovary. Also, adropin and GPR19 are highly expressed in the CL of the ovary of reproductively active mice. The fact that adropin expression in the ovary at different stages of postnatal development positively correlated with circulating progesterone and estradiol indicated that it has a role in the production of steroid hormones. Furthermore, the results of in vivo studies in pre-pubertal mice showed that adropin promotes early folliculogenesis by enhancing the proliferation (PCNA) of GCs of cortical ovarian follicles and promotes estradiol production by enhancing the expression of GPR19, StAR, CYP11A1 and aromatase proteins. Also, adropin treatment increases the Bax/Bcl2 ratio and expression of cleaved caspase-3 and ERα proteins, which may result in increased apoptosis of medullary follicles leading to the formation of a well-developed interstitium with interstitial glandular cells. Collectively, these findings indicate that adropin may be a factor that accelerates pubertal development in the ovary and could be utilized as a therapeutic approach for treating pubertal delay. © 2023 Elsevier LtdPublicationArticle Photoperiodic modulation of ovarian metabolic, survival, proliferation and gap junction markers in adult golden hamster, Mesocricetus auratus(Elsevier Inc., 2022) Sriparna Pal; Chandana Haldar; Rakesh VermaFemale reproductive physiology is greatly dependent on tight regulation of metabolic and survival factors. Photoperiod regulates female reproductive rhythms but very less information exists explaining whether photoperiod could modulate thyroid hormone homeostasis, metabolic/energy parameters along with survival, proliferation and gap junction proteins in the ovary of a long-day breeder, Mesocricetus auratus. Adult female hamsters were exposed to different photoperiodic regimes i.e., critical photoperiod (CP; 12.5L:11.5D), short photoperiod (SP; 8L:16D) and long photoperiod (LP; 16L:8D) for 12 weeks. LP upregulated thyroidal and gonadal activity as apparent by histoarchitecture, thyroid hormone profile [triiodothyronine (T3), thyroxin (T4) and thyroid stimulating hormone (TSH)], luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol (E2) and progesterone (P4) levels when compared with SP exposed hamsters. Further, LP increased thyroid hormone receptor-α/deiodinase-2 (TRα/Dio-2), estrogen receptor-α (ERα)/aromatase and insulin receptor/glucose transporter-4 (IR/GLUT-4) expressions in ovary. Interestingly, ovarian sirtuin-1 (SIRT-1) expression was also upregulated under LP condition along with cell proliferation (proliferating cell nuclear antigen or PCNA), survival (B cell lymphoma-2 or Bcl-2) and gap junction (connexin-43) markers when compared to SP exposed hamsters. We also noted elevated levels of circulatory leptin, insulin along with melatonin and its receptor (MT-1) in ovary under SP condition. Thus, we suggest that photoperiod plays a vital role in regulation of thyroid and reproductive hormone homeostasis along with key metabolic and survival markers in the ovary of adult golden hamsters, M. auratus providing further insight into the regulation of female reproductive seasonality in a long-day breeder. © 2021 Elsevier Inc.PublicationArticle Stress associated ovarian dysfunctions in a seasonal breeder Funambulus pennanti: Role of glucocorticoids and possible amelioration by melatonin(Academic Press Inc., 2022) Jayita Pal Chowdhury; Chandana HaldarStudies have shown that stress caused by lack of physical activity disrupts the normal pattern of glucocorticoid secretion which adversely affects the reproductive axis. We studied the effect of chronic movement restriction on ovarian responses in the Indian Palm Squirrel Funambulus pennanti, a highly active diurnal rodent. Physical restraint of squirrels induced stress that led to a significant increase in plasma cortisol, corticosterone and decreased 17β-estradiol level leading to follicular atresia. Ovarian Reactive Oxygen Species (ROS) content, lipid peroxidation (LPO), activities of superoxide dismutase (SOD) and catalase (CAT) enzymes increased in restrained squirrels. Elevated ROS increased the oxidative load that led to ovarian cell death as evidenced by increased Bax and decreased Bcl2 expression causing further decline in Aromatase and ERα proteins. To elaborate the mechanism(s) involved in stress induced glucocorticoid mediated oxidative damages to the ovary we extended our study by exposing ovaries in vitro to the synthetic glucocorticoid dexamethasone (200 μM). We observed that glucocorticoid receptor (GR) expression was significantly increased in dexamethasone treated ovaries in vitro with a decrease in expression of Nrf2 and HO-1 proteins. Melatonin supplementation (10 nM) along with dexamethasone significantly decreased ovarian ROS production, lipid peroxidation and increased antioxidant enzyme activities by improving the expression of Nrf2 and HO-1, reinstating the cellular redox homeostasis. Therefore, it can be suggested that physical restraint induced glucocorticoid and its receptor activation interfered with the ovarian antioxidant defense mechanism. Melatonin via its receptor MT1 significantly alleviated ovarian damages acting as a cytoprotective agent. © 2021 Elsevier Inc.