Department of Veterinary Medicine

Research in Veterinary Medicine

Research description

I have a fundamental interest in aspects of maturation in the neonatal period.

Our latest study examined pancreatic endocrine responses and anatomical development of dysmature and full-term foals during the first 10 days after birth, the critical period for gluco-regulatory adaptation. The results showed that equine β cells are responsive to glucose and arginine and release both insulin and proinsulin during the immediate postnatal period. They also suggest that newborn foals may be insulin resistant on the first day after birth. The greater % β cells in the islets and the greater total islet volume in the dysmature foals were consistent with their insulin resistance and enhanced insulin responses and suggest that the neonatal pancreas is trying to compensate for the I resistance by β cell proliferation.

Very little is known about the development of the immune system in the newborn foal. Over the next few years I plan to study maturation and susceptibility of neonatal foal immunology with respect to septicaemia.

Main collaborators

• Allen, VL. Dept. of Physiology, University of Cambridge, Cambridge CB2 3EG
• Bloomfield MR. Dept. of Physiology, University of Cambridge, Cambridge CB2 3EG
• Bryant C. Dept. of Clinical Veterinary Medicine, University of Cambridge, Cambridge CB3 OES.
• Hales, CN. Dept. of Clinical Biochemistry, University of Cambridge, Cambridge CB2 2QR
• Fowden, AL. Dept. of Physiology, University of Cambridge, Cambridge CB2 3EG

Key publications since 2001

• Beech, D.J., Sibbons, P.D., Rossdale, P.D., Ousey, J.C., Holdstock, N.B., Chavatte P., Ansari T. (2001) Organogenesis of lung and kidney in Thoroughbreds and Ponies. Equine vet J 33; 5: 438-445.
• Holdstock, N.B., Rossdale, P.D., Beech, D.J., Ansari, T., Sibbons, P.D. (2001) Microanatomical development of the equine kidney and defects associated with intra-uterine growth retardation. Pferdeheilkunde 17; 6: 659-661.
• O'Connor, S.J., Gardener, D.S., Ousey, J.C., Holdstock, N., Rossdale, P.D., Fowden, A.L., Guissani, D.A. (2002) Differential postnatal development of autonomic control of the cardiac baroreflex in the foal. Theriogenology 58; (2-4): 825-828.
• O'Connor, S.J., Fowden, A.L., Holdstock, N., Guissani, D.A., Forhead, A.J. (2002) Developmental changes in pulmonary and renal angiotensin converting enzyme concentration in fetal and neonatal horses. Reproduction, Fertility and Development 14: 1-5.
• Holdstock, N.B., Allen, V.L., Bloomfield, M.R., Hales, C.N., Fowden, A.L. (2003) Functional development of pancreatic β cells in the newborn horse. Proceedings of the Physiological Society 17th-19th Dec 2003 Cambridge (Abstr C90 p 68).
• *Holdstock, N.B., Allen, V.L., Bloomfield, M.R., Hales, C.N., Fowden, A.L. (2004) Development of insulin and proinsulin secretion in newborn pony foals. J Endocrinology 181: 469-476.
• Knottenbelt, D., Holdstock, N.B., Madigan, J. M. (2004) Equine Neonatology Medicine and Surgery. Saunders, Elsevier Science Publishing.
• O'Connor, S.J., Gardener, D.S., Ousey, J.C., Holdstock, N., Rossdale, P.D., Edwards, C. M. B., Fowden, A.L., Guissani, D.A. 2005 Development of baroreflex and endocrine responses to hypotensive stress in newborn foals and lambs. Pflugers Archiv European Journal of Physiology. Jun 2.