Swarup K

Bio: Swarup K is an academic researcher. The author has contributed to research in topics: Ultimopharyngeal body & Psittacula. The author has an hindex of 4, co-authored 12 publications receiving 44 citations.

Calcemic responses of Stannius corpuscle extract in parrotsPsittacula psittacula

Abstract: In parrots (Psittacula psittacula), i.p. injection of Stannius corpuscle extract (10 mg/ml/100 g b.wt) evokes hypocalcemia at 1 h. Thereafter, the values indicate hypercalcemia at 6 h and normocalcemia at 10 h.

Responses of serum calcium and phosphorus in the frog Rana tigrina to injection of various vitamin D analogs

Abstract: Department of Zoology, University of Gorakhpur, Gorakhpur, UP 273 009, India Received August 15, 1986 SRIVASTAV, A. K., RANI, L., and SWARUP, K. 1987. Responses of serum calcium and phosphorus in the frog Rana tigrina to injection of various vitamin D analogs. Can. J. Zool. 65: 21 1 1-21 12. Intraperitoneal injections of either vitamin D3 (4 1U/100g body wt.), 25 hydroxyvitamin D3 (100 ng/100 g body wt.), or 1,25 dihydroxyvitamin D3 (100 ng/ 100 g body wt.) for 15 days induced hypercalcemia, hyperphosphatemia, and depletion of calcium deposits in the paravertebral lime sacs in an anuran, Rana tigrina. SRIVASTAV, A. K., RANI, L., et SWARUP, K. 1987. Responses of serum calcium and phosphorus in the frog Rana tigrina to injection of various vitamin D analogs. Can. J. Zool. 65

Calcemic responses of Varanus flavescens to prolactin administration.

Abstract: The daily intraperitoneal injections of ovine prolactin to Varanus flavescens (10 I.U./0.2 ml/100 g body wt for 7 days) induced a rise in serum calcium which persisted until the end of the experiment.

Ultimobranchial body and parathyroid gland of the parrot Psittacula psittacula in response to experimental hypercalcemia.

Abstract: Psittacula psittacula when subjected to long term hypercalcemia by intramuscular injections of vitamin D2 (20,000 I.U.) on alternate days and by increasing dietary calcium, exhibit a rise in the serum calcium level after 10, 20 and 30 days of treatment as compared to their corresponding controls. The ultimobranchial cells show progressive hypertrophy up to 20th day of the treatment. From 20th day till the end of the experiment (30 days) these cells show feeble staining response. The parathyroid glands suffer from degenerative changes due to its inactivity under chronic hypercalcemia.

Human Stanniocalcin Inhibits Renal Phosphate Excretion in the Rat

Abstract: Stanniocalcin (STC) is a glycoprotein hormone first identified in bony fishes where it counteracts hypercalcemia by inhibiting gill calcium uptake and stimulating renal inorganic phosphate (Pi) reabsorption. Human STC (hSTC) has recently been cloned and sequenced and is highly homologous to the fish hormone at the amino acid level. The objective of this study was to examine the possible effects of hSTC on electrolyte homeostasis and renal function in the rat. Recombinant hSTC was expressed in bacteria and purified by metal-ion affinity chromatography and reverse-phase high performance liquid chromatography. Anesthetized animals were given bolus infusions of 1, 5, or 10 nmol hSTC per kilogram of body weight. Control animals received solvent alone. The most effective dosage was 5 nmol/kg, which caused significant reductions in both absolute and fractional phosphate excretion in comparison with control rats. The hSTC had no effect on the renal excretion of other ions, the glomerular filtration rate, renal blood flow, blood pressure, or plasma electrolytes (Na+, K+, Ca2+, Pi, Mg/+). The maximum effect of hSTC on phosphate excretion was observed 60-80 minutes postinjection. Lesser effects were obtained with higher and lower dosages of hormone. When renal cortical brush-border membrane vesicles were isolated from control and hormone-treated animals 80 minutes postinjection, the rate of Na+/Pi cotransport was found to be 40% higher in vesicles from hormone-treated animals (p < 0.01; 5 nmol hSTC/kg). Together, the renal clearance and membrane vesicle data indicate that hSTC participates in the renal regulation of Pi homeostasis in mammals.

Prospect of a stanniocalcin endocrine/paracrine system in mammals.

Abstract: Stanniocalcin (STC) is a calcium- and phosphate-regulating hormone produced in bony fish by the corpuscles of Stannius, which are located close to the kidney. It is a major antihypercalcemic hormon...

Identification of a stanniocalcin paralog, stanniocalcin-2, in fish and the paracrine actions of stanniocalcin-2 in the mammalian ovary.

Abstract: Stanniocalcin is a glycoprotein hormone important in the maintenance of calcium and phosphate homeostasis in fish. Two related mammalian stanniocalcin genes, STC1 and STC2, were found to be expressed in various tissues as paracrine regulators. We have demonstrated the existence of a second stanniocalcin gene in fish, designated fish STC2, with only 30% identity to fish STC1. However, phylogenetic analysis and comparison of the genomic structure of STC genes in vertebrates indicated that STC1 and STC2 genes were probably derived from a common ancestor gene. Based on the prominent expression of mammalian STC1 in the ovary, we tested STC2 expression in rat ovary and the regulation of STC2 expression by gonadotropins. Treatment of immature rats with pregnant mare serum gonadotropin increased STC2 transcripts, whereas subsequent treatment with human chorionic gonadotropin suppressed STC2 expression. Real-time PCR analyses also demonstrated that STC2 is expressed mainly in thecal layers. In situ hybridization s...

Quantitative changes in the frequency and distribution of the C-cell population in the rat thyroid gland with age.

Abstract: The development of calcitonin cells (C-cells) was investigated in rat thyroid glands from birth to 120 days, using an immunoperoxidase technique and a point-counting method. The proportion of C-cells to follicular cells was 4.5% on the day of birth and increased progressively to 10.4% by 120 days. The highest density of C-cells was noted in the mid-region of the lobes along a longitudinal axis. The caudal and cephalic regions of the lobes contained smaller numbers of C-cells. The C-cells tended to be more numerous in the posterior aspects of the lobes. Although the numbers of C-cells in 120-day-old animal were markedly increased as compared to animals at the time of birth, the cell distributions within the glands were similar at all ages.