Histochemical, clinical, and in vitro β cell responses in a neonate with persistent hyperinsulinaemic hypoglycaemia of infancy
- aThe immunohistochemistry data were presented at the 16th International Congress of Clinical Chemistry, London, 8–12 July 1996 and the case was presented at the 9th Asian Congress of Paediatrics, Hong Kong, 23–27 March 1997. Department of Chemical Pathology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People’s Republic of China, bAnatomical and Cellular Pathology, cDepartment of Paediatrics
- Dr Panesar. Email: nspanesar{at}cuhk.edu.hk
- Accepted 11 February 1998
Abstract
When treatment with diazoxide and somatostatin for persistent hyperinsulinaemic hypoglycaemia of infancy failed, subtotal pancreatectomy was performed on a neonate on day 41. The pancreatic tissue was saved and used for immunohistochemical and cell culture studies. The initial immunohistochemistry of β cells for insulin was negative, using a 1 in 200 dilution of insulin antiserum, but positive results were obtained with an increased concentration of the antiserum.
The insulin to somatostatin cell ratio in islets of Langerhans was about 1:1, with no somatostatin cells outside the islets. Glucose stimulated insulin secretion in a concentration dependent manner in vitro. Isobutyl methyl xanthine doubled insulin secretion, but lithium had no effect. The glucose stimulated insulin secretion was inhibited by somatostatin, epinephrine, and in the absence of Ca2+.
In view of the normal in vitro responses of β cells to various secretory analogues, the lack of responsiveness to somatostatin analogue before pancreatectomy may not have been due to deficiency or resistance to somatostatin, but to β cell hyperplasia overwhelming the paracrine regulatory mechanism(s).
- persistent hyperinsulinaemic hypoglycaemia of infancy
- somatostatin
- in vitro cell studies
- negative immunohistochemistry
- steric hindrance
