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Biomedical subjects

P Gray

Publications and source records attributed to P Gray.

At least 127 records · Page 7Linked to original sources
PubMed1976

Effects of lithium on open field behavior in "stressed" and "unstressed" rats.

Rats were tested for 3 min per day, for 4 successive days, in an open field apparatus, 20 min after injection of either lithium chloride (2 mEq/kg) or physiological saline. In the first experiment, the open field was illuminated with moderate white light for some rats (stress condition) and dim red light for others (non-stress condition). In the second experiment, some rats received an electric foot shock 5 h before each open field test (stress condition) and others received no foot shock (non-stress condition). In both experiments, lithium significantly reduced rearing behavior in the stressed, but not the unstressed, rats. Lithium also reduced horizontal locomotion, but this effect appeared in both stressed and unstressed rats. In the second experiment, defecation was measured, and it was found that lithium-treated rats defecated less than saline-treated rats in the first session, but not in subsequent sessions, due to habituation which occurred for the saline rats.

Animals↗
PubMed1976

Calcium balance in drug-induced osteomalacia: response to vitamin D.

The effect of oral vitamin D3 therapy on calcium balance was compared in 18 institutionalized subjects with drug-induced osteomalacia and in 18 similar subjects without osteomalacia. The subjects with osteomalacia were receiving standard doses of phenytoin and phenobarbital. Diagnosis of osteomalacia was based on low serum calcium and phosphorus, elevated alkaline phosphatase, and appropriate roentgenographic bone changes. The study group achieved positive calcium balance at approximately 975 IU of vitamin D3 per day, while the control group achieved positive calcium balance at approximately 380 IU of vitamin D3 per day. The difference is highly significant (p less than 0.001). These data support previous observations that the osteomalacia of patients receiving anticonvulsant drugs is related to the drugs and that these patients require supplemental doses of vitamin D.

Adolescent↗
PubMed1976

Effect of prestimulation on avoidance responding in rats, and hormonal dependence of the effect.

Rats were tested daily in a free-operant avoidance task and were found to make more avoidance responses in sessions preceded by a brief period of prestimulation than in control sessions. Footshock, air blast, and handling were effective sources of prestimulation for this effect. Further experiments showed that the effect of prestimulation depended on the presence of circulating mineralocorticoid and not on any other adrenal or pituitary hormone. Adrenalectomy, but not hypophysectomy, abolished the effect. The effect was also abolished in intact rats by maintaining them on saline drinking fluid, a procedure that inhibits mineralocorticoid production. In either adrenalectomized rats or intact, saline-maintained rats, injection of mineralocorticoid permitted the effect of prestimulation to reappear while leaving the nonprestimulated response rate unaffected.

Adrenalectomy↗
PubMed1975

Effect of adrenocorticotropic hormone on conditioned avoidance in rats interpreted as state-dependent learning.

Rats were given one training trial that was followed 2 days later by one test trial in a "step-out" passive avoidance task. Each rat was injected with either adrenocorticotropic hormone (ACTH) or placebo before training and before testing. Four groups of rats were used, representing the 4 possible training-testing injection combinations: placebo-placebo, placebo-ACTH, ACTH-placebo, and ACTH-ACTH. ACTH given in testing increased avoidance for subjects that had received ACTH in training and decreased avoidance for those that had received placebo in training.

Adrenocorticotropic Hormone↗