TY - JOUR
T1 - The pancreas of the naked mole-rat (Heterocephalus glaber)
T2 - An ultrastructural and immunocytochemical study of the endocrine component of thermoneutral and cold acclimated animals
AU - Kramer, Beverley
AU - Buffenstein, Rochelle
N1 - Funding Information:
Clearance for animal use and histology was obtained from the Animal Ethics Committee of the University of the Witwatersrand (AEC No. 2000/70/1). The assistance of the following CCNY students, Adriana Biney, David Edgecomb, Hyesin Joy Kang, and Ting Yang in the collection of glucose tolerance data is gratefully acknowledged. This part of the study was approved by the IACUC of CCNY (#0414). The authors thank Dr. M. Birkhead and Mrs. L. York for excellent technical assistance. The Research Council of the University of the Witwatersrand is acknowledged for financial assistance.
PY - 2004/12
Y1 - 2004/12
N2 - Endocrine cell distribution within the islets of Langerhans may vary both between species and under different energetically demanding conditions such as cold acclimation. The naked mole-rat, Heterocephalus glaber, lacking an effective insulatory pelage, is effectively a poikilotherm, yet it shows a typical mammalian cold-acclimation response by substantially increasing food intake to meet higher energy requirements when housed at lower temperatures. The endocrine component of the pancreas of thermoneutral and cold-acclimated naked mole-rats was thus characterized using immunocytochemistry and ultrastructural analyses. Four distinct endocrine cells were identified: α (glucagon-producing), β (insulin-producing), δ (somatostatin- producing), and PP (pancreatic polypeptide-producing) cells. Distribution of these cells differed from that of other rodents, in that β cells formed the mantle while α cells formed the core of the islets. This distribution may contribute to the observed insulin insensitivity of this species, as indicated in abnormal responses to glucose tolerance tests. Insulin-producing cells, however, were more numerous than glucagon-producing cells. This ratio was unchanged with cold acclimation. Immunoreactivity of α and β cells was more intense in cold-acclimated than in thermoneutral animals, possibly indicative of a change in hormonal production in animals housed at a lower temperature.
AB - Endocrine cell distribution within the islets of Langerhans may vary both between species and under different energetically demanding conditions such as cold acclimation. The naked mole-rat, Heterocephalus glaber, lacking an effective insulatory pelage, is effectively a poikilotherm, yet it shows a typical mammalian cold-acclimation response by substantially increasing food intake to meet higher energy requirements when housed at lower temperatures. The endocrine component of the pancreas of thermoneutral and cold-acclimated naked mole-rats was thus characterized using immunocytochemistry and ultrastructural analyses. Four distinct endocrine cells were identified: α (glucagon-producing), β (insulin-producing), δ (somatostatin- producing), and PP (pancreatic polypeptide-producing) cells. Distribution of these cells differed from that of other rodents, in that β cells formed the mantle while α cells formed the core of the islets. This distribution may contribute to the observed insulin insensitivity of this species, as indicated in abnormal responses to glucose tolerance tests. Insulin-producing cells, however, were more numerous than glucagon-producing cells. This ratio was unchanged with cold acclimation. Immunoreactivity of α and β cells was more intense in cold-acclimated than in thermoneutral animals, possibly indicative of a change in hormonal production in animals housed at a lower temperature.
KW - Cold acclimation
KW - Iimmunocytochemistry
KW - Islet cell distribution
KW - Naked mole-rat
KW - Pancreas
KW - Ultrastructure
UR - http://www.scopus.com/inward/record.url?scp=9244228534&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=9244228534&partnerID=8YFLogxK
U2 - 10.1016/j.ygcen.2004.09.006
DO - 10.1016/j.ygcen.2004.09.006
M3 - Article
C2 - 15560867
AN - SCOPUS:9244228534
VL - 139
SP - 206
EP - 214
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
SN - 0016-6480
IS - 3
ER -