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
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 -