Welcome Dr. Ajai Kumar Srivastav to American Journal of Agricultural Research

Dr. Ajai Kumar Srivastav
Emeritus Professor,
Department of Zoology,
D.D.U. Gorakhpur University

Biography & Research Interest

Welcome Dr. Ajai Kumar Srivastav to Join the Editorial Board of American Journal of Agricultural Research. Dr. Ajai Kumar Srivastav is the Emeritus Professor in Department of Zoology of D.D.U. Gorakhpur University. Prof. Srivastav’s research endeavors concern the area of endocrine toxicity, heavy metal toxicity and comparative vertebrate endocrinology. He has made a number of noteworthy contributions in these field of research which are summarized below:

ENDOCRINE TOXICITY:  Prof. Srivastav’s interest lies in investigating the effects of organophosphates, pyrethroids, heavy metal and plant-derived pesticides on the blood electrolytes and calcium regulating endocrine glands in fish and mammals. The major contributions are:

Provided a direct effect of inorganic mercury on osteoclasts which is FIRST REPORT by using the mRNA expressions of osteoclastic markers (tartrate–resistant acid phosphatase: TRAP and cathepsin K) and osteoblastic marker (insulin–like growth factor–I: IGF–I). Considering these results scale assay system will be useful for analysis of environmental contaminant on bone metabolism.
Investigated the effects of organophosphate, pyrethroid, heavy metals and botanical pesticides on the ultimobranchial gland of fish. These studies are FIRST REPORTS and new to science.
Reported that in both goldfish (a freshwater teleost) and wrasse (a marine teleost), the osteoclastic activity in the scales was significantly suppressed by 3-hydroxybenz[a]anthracene (3-OHBaA) and 4-hydroxybenz[a]anthracene (4-OHBaA). This is the FIRST REPORT to demonstrate that 3-OHBaA and 4-OHBaA inhibited both osteoclasts and osteoblasts and disrupted the bone metabolism in teleosts.
Demonstrated that in teleosts, tributyltin acetate (TBTA) inhibits osteoblastic activity without affecting osteoclastic activity and disrupts the calcium metabolism, including the calcemic hormone calcitonin in goldfish. These data are FIRST REPORT.
Established the inhibitory effects of organophosphate, pyrethroid and heavy metals on the corpuscles of Stannius (an endocrine gland present in fishes only) of fish. These studies are FIRST REPORTS and new to science.
Reported the effects of botanical pesticides on blood electrolytes of fish which was not reported earlier.
Investigated the effects of organophosphate and pyrethroid on the prolactin cells of fish. These studies are FIRST REPORTS and new to science.
Observed the effects of chlorpyrifos on the blood electrolytes, calcitonin cells and parathyroid glands of rat. These are new findings not reported earlier.
Heavy metal toxicity: Prof. Srivastav conducted research on mono-therapy and combined therapy on the protective effect of chelating agents and antioxidant therapy against heavy metal’s toxicity in rat. Efficient therapeutics approaches to treat mercury intoxication are still not available. His investigation is first of its kind regarding the protection of combined treatment (suitable antidote) against mercury toxicity. He is presently working on the detoxification strategy with the combination of natural products and antioxidant supplementation. Exploring the potential of combination therapy in protecting against mercury induced oxidative stress would likely result in a novel approach to this clinical problem. This entire research work will open a new chapter for both research and application in the pharmaceutical industry suggesting combined therapy as a novel approach. It has been presumed by Prof. Srivastav’s findings that combination therapy for monitoring mercury toxicity may be highly successful and co-therapy with antioxidants/plant products and chelating agents may be exploited for future formulation design with an aim to reduce the mercury body burden and will ultimately be helpful in developing a suitable and cost effective drug for mankind to prevent mercury toxicity progression and helps the patient in neutralizing the free radicals and restoration of the antioxidant defense system.
comparative vertebrate endocrinology: Prof. Srivastav has made in-depth studies on the regulation of calcium in vertebrates. His focused outstanding original contributions in the field has made an excellent impact on others working in the area of comparative endocrinology. He has made a commendable contribution in furthering the knowledge concerning the role of hormones in lower vertebrates. Prof. Srivastav published five review articles, two book chapters and numerous scientific papers in the field of comparative vertebrate endocrinology contributing newer findings like:
Reported effects of corpuscles of Stannius (present only in teleosts) extract in elasmobranch, frog , snake and bird which were FIRST REPORTS and suggested in 1982 that receptors for the hormone stanniocalcin are also present in non-piscine vertebrates. This has opened a new avenue of research and prompted workers world-over to investigate along this line and found stanniocalcin-like substances in kidney and other tissues of mammals and even in humans.
He established role of vitamin D and its metabolites in fish calcium regulation which was denied by earlier workers world over. Now scores of reports are available which accepts Prof. Srivastav’s finding.
Over-ruled the hypothesis that calcitonin acts as an anti-hypercalcemic hormone in fish
The effect of 1,25 (OH)2D3 on stanniocalcin level of tilapia (FIRST REPORT)
Investigated the effects of the prolactin and 1,25 (OH)2D3 on the plasma electrolytes and calcium regulating endocrine glands (ultimobranchial and parathyroid glands) of pigeon (FIRST REPORT)
Hypercalcemic effect of vitamin D and its metabolites in reptiles (FIRST REPORT)
Effects of prolactin on calcium regulation in amphibian and reptiles (FIRST REPORT)
Established for the first time correlation between glucagon and calcium regulating endocrine glands in fish, amphibian, bird and mammal
Reported for the first time calcitonin-immunoreactive cells in the intestine of goldfish
Hypocalcemic effect of calcitonin in fish (which was denied earlier by most investigators) under diminished circulating levels of calcitonin
For the first time reported effects of 1,25 (OH)2D3 in newts and lizard
The hypercalcemic effect of vitamin D in fishes independent of environmental calcium content (FIRST REPORT)
For the first time detected estrogen receptors in the teleost ultimobranchial gland and occurrence of calcitonin secretion by estrogen
Localized calcitonin immuno-reactive cells in the digestive tract of the amphioxus (FIRST REPORT)
For the first time reported the effect of calcitonin in a cartilaginous fish, sting ray
Characterized calcitonin like substance from the Brockmann Bodies of medaka (FIRST REPORT)
Determined amino acid sequences of N-terminal calcitonin in some vertebrates (FIRST REPORT)
examined the effect of fugu PTH1 on goldfish scale osteoblastic and osteoclastic activities and compared the actions of fugu PTH1 with those of human PTH (FIRST REPORT)
Reported for the first the direct effects of prostaglandin E2 on osteoclasts and osteoblasts of teleosts scales by using in vitro assay system
cDNA of CaSR was cloned from the regenerating scales of goldfish and the effect of acceleration loading by vibration (3G) on CaSR mRNA expression was investigated (FIRST REPORT)
Reoprted for the first that monohydroxylated polycyclic aromatic hydrocarbons suppress spicule formation in sea urchins (Hemicentrotus pulcherrimus)


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