Viability of the neonatal rat isolated brainstem preparation by 31P MRS.

The isolated brainstem-spinal axis from the neonatal rat is an established model for studying neuronal responses of the ventilatory control system, however, its viability has not been clearly established. We studied the brainstem-spinal axis from newborn rats at 8.5 T with 31P NMR spectroscopy.

1H-NMR measurement of fractional dissociation of imidazole in intact animals.

The alphastat hypothesis states that intracellular acid-base status is regulated to maintain constancy of the fractional dissociation of intracellular protein and enzyme imidazole-histidine (alpha-imidazole). A major drawback of this theory has been the lack of a means to directly measure alpha-imidazole in intact animals. We developed a method for directly measuring alpha-imidazole in intact unanesthetized animals using 1H-nuclear magnetic resonance spectroscopy (NMR).

Effects of temperature on muscle pHi and phosphate metabolites in newts and lungless salamanders.

The effect of acute alterations in body temperature (BT) on intracellular pH (pHi) and phosphate metabolites was assessed in white skeletal muscle of intact newts and lungless red-backed salamanders using 31P-nuclear magnetic resonance spectroscopy. pHi decreased with increasing BT in the tail muscle of both newts and lungless red-backed salamanders. The change in pH with change in temperature from 10 to 30 degrees C was -0.

Effects of hypothermia on rat brain pHi and phosphate metabolite regulation by 31P-NMR.

The effects of arterial alphastat regulation on brain intracellular pH (pHi) and several phosphate metabolites were assessed in anesthetized rats during hypothermia (28.6 +/- 0.2 degrees C) and normothermia (36.

Effects of hydralazine on in vivo tumor energy metabolism, hematopoietic radiation sensitivity, and cardiovascular parameters.

Energy metabolism of murine FSaII foot tumors was studied by in vivo 31P-MRS in C3Hf/Sed mice. Spectroscopy was performed following exposure to escalating doses of hydralazine (HYD) ip. At 0.