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M.S. Amarendhra Kumar

M.S. Amarendhra Kumar
Peptidergic Neurons

Campus Phone:



  • PhD - University of Florida - 1980
  • MS - Kansas State University - 1976
  • B.V.Sc and M.V.Sc - Mysore Veterinary College, India - 1970 and 1973
  1. Ginn, J.A., Kumar, M.S.A., McKiernan, B.C., Powers, B.E. 2008. Nasopharyngeal turbinates in brachycephalic dogs and cats. Journal of the American Animal Hospital Association.
  2. Singer, L.A., Kumar, M.S.A., Gavin, W., Ayres, S.L. 2004. Predicting the onset of parturition in the goat by determining progesterone levels by enzyme immunoassay. Small Ruminant Research.
  3. Zhang, Q., Rosenberg, M., Kugel, G., Agarwal, R.K., Phillips, J., Kumar, M.S. 2003. Effect of nitrous oxide on intracellular events of GT1-7 GnRH-secreting neurons.. Anesthesia progress.
  4. Knight, T.E., Kumar, M.S.A. 2003. Lead toxicosis in cats - A review. Journal of Feline Medicine and Surgery.
  5. Kirker-Head, C.A., Chandna, V.K., Agarwal, R.K., Morris, E.A., Tidwell, A., O'Callaghan, M.W., Rand, W., Kumar, M.S.A. 2000. Concentrations of substance P and prostaglandin E2in synovial fluid of normal and abnormal joints of horses. American Journal of Veterinary Research.
  6. Karuri, A.R., Ayres, S., Kumar, M.S.A. 2000. Regional distribution of gonadotropin-releasing hormone-like, β-endorphin-like, and methionine-enkephalin-like immunoreactivities in the central nervous system of the goat. Brain Research Bulletin.
  7. Karuri, A.R., Engelking, L.R., Kumar, M.S.A. 1998. Effects of halothane and methoxyflurane on the hypothalamic-pituitary- adrenal axis in rat. Brain Research Bulletin.
  8. Karuri, A.R., Kugel, G., Engelking, L.R., Kumar, M.S.A. 1998. Alterations in catecholamine turnover in specific regions of the rat brain following acute exposure to nitrous oxide. Brain Research Bulletin.
  9. Karuri, A.R., Agarwal, R.K., Engelking, L.R., Kumar, M.S.A. 1998. Effects of halothane and methoxyflurane on regional brain and spinal cord substance P-like and betaendorphin-like immunoreactivities in the rat. Brain Research Bulletin.
  10. Agarwal, R.K., Kugel, G., Karuri, A., Gwosdow, A.R., Kumar, M.S.A. 1996. Effect of low and high doses of nitrous oxide on preproenkephalin mRNA and its peptide methionine enkephalin levels in the hypothalamus. Brain Research.
  11. Court, M.H., Dodman, N.H., Greenblatt, D.J., Agarwal, R.K., Kumar, M.S.A. 1993. Effect of midazolam infusion and flumazenil administration on epinephrine arrhythmogenicity in dogs anesthetized with halothane. Anesthesiology.
  12. Agarwal, R.K., Chandna, V.K., Engelking, L.R., Lightbown, K., Kumar, M.S.A. 1993. Distribution of catecholamines in the central nervous system of the pig. Brain Research Bulletin.
  13. Gwosdow, A.R., O'Connell, N.A., Spencer, J.A., Kumar, M.S.A., Agarwal, R.K., Bode, H.H., Abou-Samra, A.B. 1992. Interleukin-1-induced corticosterone release occurs by an adrenergic mechanism from rat adrenal gland. American Journal of Physiology - Endocrinology and Metabolism.
  14. Kumar, M.S.A., Becker, T., Ebert, K. 1991. Distribution of substance P, GnRH, Met-enkephalin in the central nervous system of the pig. Brain Research Bulletin.
  15. Marchand, J.E., Hershman, K., Kumar, M.S.A., Thompson, M.L., Kream, R.M. 1990. Disulfiram administration affects substance P-like immunoreactive and monoaminergic neural systems in rodent brain. Journal of Biological Chemistry.
  16. Gwosdow, A.R., Kumar, M.S.A., Bode, H.H. 1990. Interleukin 1 stimulation of the hypothalamic-pituitary-adrenal axis. American Journal of Physiology - Endocrinology and Metabolism.
  17. Thompson, M.L., Miczek, K.A., Noda, K., Shuster, L., Kumar, M.S.A. 1988. Analgesia in defeated mice: Evidence for mediation via central rather than pituitary or adrenal endogenous opioid peptides. Pharmacology, Biochemistry and Behavior.
  18. Kream, R.M., Clancy, A.N., Kumar, M.S.A., Schoenfeld, T.A., Macrides, F. 1987. Substance p and luteinizing hormone-releasing hormone levels in the brain of the male golden hamster are both altered by castration and testosterone replacement. Neuroendocrinology.
  19. MACRIDES, F., SCHOENFELD, T.A., CLANCY, A.N., KUMAR, M.S.A., KREAM, R.M. 1987. Hormones and Neurotransmitters in the Mammalian Olfactory System. Annals of the New York Academy of Sciences.
  20. Patel, V., Borysenko, M., Kumar, M.S.A. 1985. Effects of Δ9-tetrahydrocannabinol (THC) on plasma hormone levels and splenic natural killer (NK) cell activity. Federation Proceedings.

General Research Interests

Central Integrative Processes Controlling Gonadal Function: Role of peptidergic neurons, with emphasis on GnRH-Catecholamine-endogenous Opioid peptidergic neural interaction

Selected Research Projects

  • Reproductive hazards associated with exposure to nitrous oxide: Epidemiological data from human and animal studies indicate that chronic exposure to nitrous oxide (N2O) results in impaired reproductive function and decreased fertility rates. Preliminary studies performed in our laboratory indicate that N2O exposure disrupts estrous cyclicity with concomitant alterations in diencephalic opioid peptide concentrations, catecholamine turnover rates, and gonadotropin-releasing hormone (GnRH) concentrations. Furthermore, in vitro studies performed in our laboratory, utilizing immortalized GnRH neurons (GT1-7 cells), indicate that exposure to N2O results in significant decreases in proGnRH mRNA concentrations. These results are consistent with our overall hypothesis that N2O impairs hypothalamic control of gonadotropin release, either by directly acting on GnRH neurons or by altering upstream neural influences on GnRH neurons.

  • Effects of lead exposure during early development on neural circuits controlling puberty onset and hypothalamic-pituitary axis: This is a collaborative research effort with Drs. Dees and Bratton at Texas A&M University. We will examine the effects of LEAD on the molecular and cellular events upstream of the GnRH neuron crucial to gonadotropin secretion regulation, as well as signaling pathways, and metabolism of GnRH peptide in cultured GT1-7 cells.

Research and Clinical Interests

  • Radioimmunoassay of steroidal hormones, peptide transmitters.
  • HPLC- analytical and quantitative.
  • Signal transduction- Western blot methodology
  • Histological and histochemical methods are available in the laboratory

Major Specialized Equipment

The laboratory has HPLC setup with UV, on-line radioisotope and electrochemical detection capabilities. Other facilities in the laboratory can support protein work. Other equipment can support histological, immunohistochemical studies on organs/ tissues. The lab also has equipment for conducting routine protein biochemistry, as well as radioimmunoassays.Laboratory Personnel
  • Quanshun Zhang, Post-doctoral fellow