Temperature and activity responses to sucrose concentration reductions occur on the 1st but not the 2nd day of concentration shifts, and are blocked by low, constant glucocorticoids

Previous findings (N. Pecoraro, J. Chou-Green, & M. F. Dallman, 2003; N. Pecoraro & M. F. Dallman, 2005) indicated that unexpected reductions in sucrose concentration in once daily meals result in a febrile response on the 1st, but not the 2nd day of a concentration shift. This study shows that this day-specific fever is blocked by adrenalectomy accompanied by constant low corticosterone replacement. Rats implanted with telemetry probes were adrenalectomized and given low-corticosterone pellets or were sham operated. Food-restricted rats were given 2 rounds of sucrose concentration downshifts, as follows: 32% sucrose (14 days), 4% sucrose (6 days), 32% sucrose (4 days), and 4% sucrose (4 days). Intact rats showed more pronounced anticipation of the sucrose than did rats having low, clamped corticosterone. Only intact rats showed a 4-hr, postshift temperature burst on the 1st, but not the 2nd day of the shift to 4% sucrose, during both rounds of shifting. Increased activity accompanied the fever. These data confirm previous findings, show them to be dependent on high corticosterone, and appear to be related to a host of day-specific alterations in other motor outflows following unexpected downward shifts in palatable sucrose concentrations.     

Comparative clinical reliability of fasting plasma glucose and glycosylated hemoglobin in non-insulin-dependent diabetes mellitus

Because accurate determination of glycosylated hemoglobin (GHb) is difficult and relatively expensive in comparison with the modest cost and ready availability for tests of fasting plasma glucose (FPG), we examined the reliability of repeated measurements of FPG and GHb in typical diabetic outpatients taken in the usual clinical setting. We determined FPG and GHb concurrently on three separate occasions spanning 4 wk in 41 patients with non-insulin-dependent diabetes mellitus (NIDDM) and, for contrast, 5 with insulin-dependent diabetes mellitus (IDDM). Most of the NIDDM subjects were obese, with initial FPG levels ranging from 93 to 355 mg/dl. The reliability of each test was estimated by calculating two measures: the intraclass correlation coefficient (rho I) and the coefficient of variation (CV) for the repeated test values. For NIDDM patients treated with diet or oral hypoglycemic agents (OHA), rho I for FPG, log(FPG), and GHb were very similar. For insulin-treated NIDDM patients, rho I for FPG was somewhat lower than the coefficient in other treatment groups, and the reliability of FPG by this measure did not match the reliability of GHb within the limits of statistical significance. By analyzing the CV of test values repeated within subject, the reliability of FPG did not differ from GHb in any of the NIDDM treatment groups. Although patients were recruited sequentially to minimize sample selection bias, caution must be exercised in the interpretation of the statistical analyses of reliability with either rho I or CV due to limitations imposed by small sample size.(ABSTRACT TRUNCATED AT 250 WORDS)