Projects per year
Methods: In the first study (Stimulus Generalisation study), hyperinsulinaemic hypoglycaemic (2.8 mmol•L-1) glucose clamps were performed in non-diabetic rodents exposed to prior moderate duration cold (4OC for 3 hours) or control conditions). In the second study (Dishabituation Study), rodents exposed to prior RH or saline injections over 4-weeks underwent a longer duration cold (4OC for 4.5 hours) exposure followed 24 hrs later by a hyperinsulinaemic hypoglycaemic (2.8 mmol•L-1) glucose clamp. Output measures were counterregulatory hormone responses during experimental hypoglycaemia.
Results: Moderate duration cold exposure blunted the adrenaline response (15,266 ± 1,920 vs 7,981 ± 1,258 pmol•L-1, Control vs. Cold, P < 0.05) to next day hypoglycaemia in healthy non-diabetic rodents. In contrast, the suppressed adrenaline response (Control 5,912 ± 1,417 vs. RH 1,836 ± 736 pmol•L-1; P < 0.05) that is associated with RH was restored following longer duration cold exposure(RH + Cold 4,756 ± 826 pmol•L-1; P = NS vs control).
Conclusions/interpretation: Non-diabetic rodents exhibit two cardinal features of habituation, namely stimulus generalisation and dishabituation. These findings provide further support for the hypothesis that suppressed counterregulatory responses following exposure to recurrent hypoglycaemia in diabetes result from habituation.
- Counterregulatory responses
- Impaired awareness
- Type 1 diabetes