Cummings School of Veterinary Medicine at Tufts University
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. Fred S. Pike DVM, Diplomate ACVS, MSA Kumar BVSc, MVSc, MS, PhD,Randy J. Boudrieau DVM, Diplomate ACVS and ECVS. Reduction and fixation of cranial cervical fracture/luxations using screws and polymethylmethacrylate (PMMA) cement: A distraction technique applied to the base of the skull in 13 Dogs (Manuscript ID VSU-10-220-R1), Veterinary Surgery (in Press, 2011).
  2. Pike FS, Kumar MSA, Boudrieau RJ.  Réduction anatomique et fixation des fractures/luxations des vertèbres cervicales crâniales avec vis et polyméthylméthacrylate : Technique de distraction appliquée à la base du crâne chez 13 chiens.  Communications libres, Congrès National de l’Association Française des Vétérinaires d’Animaux de Compagnie (AFVAC) ; Strasbourg, France.  28-30 novembre 2008. Paper submitted in 2010 for publication.
  3. Clinically oriented Anatomy of the Dog and Cat- Under contract with Linus Publishers, NY, approximate date of publication- 2012.  
  4. Joseph, A., Kumar, A., O'Connell, N.A., Agarwal R.K., and Gwosdow, A.R. Interleukin-1 alpha stimulates dopamine release by activating type II protein inase A in pc-12 cells. Am. J. Physiol. 269: E1083-E1088,1995.
  5. Karuri, A., Kumar, M.S.A and Mukhophadhyay, D. Vascular endothelial growth factor: Regulation of expression in the uterus by endocrine factors. J. Endocrinology, 159: 489-499, 1998.
  6. Karuri, A. , S. Ayres and Kumar, M.S.A. Regional distribution of gonadotropin-releasing hormone-like, beta endorphin-like, and methionine-enkephalin- like immunoreactivities in the central nervous system of the goat. Brain Res. Bull. 51: 63-68, 2000.
  7. Zhang, Q, Rosenberg M., Kugel, G., Agarwal R.K, Phillips J and Kumar, M.S.A. Effect of nitrous oxide on intracellular events of GT1-7 GnRH secreting neurons. In Press: Anesth. Progress (2003).

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.

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