GLUCOPRIVATION COUNTERACTS EFFECTS OF TESTOSTERONE ON DAILY TORPOR INSIBERIAN HAMSTERS

We tested whether 1) glucose availability is a signal for initiation o f torpor in male hamsters and 2) glucoprivation can override the inhib itory effects of androgens on daily torpor. Male hamsters maintained a t ambient temperatures of 8-16 degrees C were injected with 2-deoxy-D- glucose (2DG), a glucose analogue that interferes with cellular glucos e oxidation. 2DG (2,000-2,500 mg/kg body mass) induced torpor within 1 h of treatment in normal adult males in reproductive condition and in those bearing testosterone (T)-filled capsules that produced supraphy siological blood T concentrations; body temperatures were reduced from 37 to 25 degrees C for several hours. Latency to torpor was increased and duration of torpor was decreased in the T-treated hamsters. Food intake decreased substantially both on the day of torpor and on the su cceeding day. Glucoprivation appears to counteract the potent inhibito ry effect of androgens on torpor and induces a hypometabolic state tha t results in overall energy savings.