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Biomedical subjects

J L Falk

Publications and source records attributed to J L Falk.

At least 127 records · Page 7Linked to original sources
PubMed1979

Serum phenobarbital and barbital concentrations in rats on a limited food regimen.

Serum barbiturate levels were tracked for several hours in food deprived rats given 40, 60 or 80 mg/kg (SC) of either phenobarbital or barbital. All 3 phenobarbital doses produced peak serum drug levels at 1.5 hr postinjection. Serum barbital concentrations peaked 3 hr after both 60 and 80 mg/kg barbital doses while the 40 mg/kg dose produced a stable low drug level throughout the 4 postinjection hours. For both barbiturates administered, 40 mg/kg doses produced lower serum drug levels than either 60 or 80 mg/kg. The differences in serum drug concentrations between the latter two dose levels were inconsistent over time.

Animals↗
PubMed1978

Stimulus persistence in CFF: overarousal or underactivation?

The physiological basis of hypothesized adult age increases in the persistence of stimuli was studied in 16 young (X age 19.1 years) and 16 old (X age 70.1 years) male and female subjects. Changes in CFF threshold and skin conductance were measured as a function of loud white noise activation and artificial pupil. CFF was significantly lower in the old group and with artificial pupil in both age groups. Significant effects were also found for activation x sex and activation x age x sex. Skin conductance change was significant for activation, activation x sex, artificial pupil x age, artificial pupil x order and artificial pupil x order x activation. The results were interpreted as supporting an overarousal basis of an age increase in stimulus persistence.

Adolescent↗
PubMed1977

Ethanol dependence as a determinant of fluid preference.

Rats made dependent on ethanol by a schedule-induced polydipsia procedure preferred 5% ethanol to an increasing concentration of dextrose solution to a greater extent than animals on a non-dependent, non-polydipsic procedure which allowed an equivalent opportunity to drink ethanol, confirming a previous study. Two corresponding groups of animals drinking isotonic (0.9%) NaCl rather than 5% ethanol behaved similarly to the latter group, changing to a dextrose preference at a lower dextrose concentration than the ethanol polydipsic group. Therefore, neither the intermittent food regimen (polydipsia-generating procedure) in itself, nor a history of isotonic saline polydipsia biased fluid preference against dextrose solution choices. The enhanced preference for ethanol over dextrose solutions shown by the ethanol polydipsic group can be attributed to physical dependence rather than regiment produced artifacts.

Animals↗
PubMed1976

Ethanol elimination rates in normal and ethanol dependent animals.

Ethanol elimination rates were determined in rats using an intravenous route of ethanol administration after several experimental manipulations. Twenty-four hr food deprivation resulted in a 30% reduction to 35 mg/100ml blood/hr in elimination rate from a non-deprived rate of 50 mg/100 ml blood/hr. After 2 months of ethanol drinking (5% v/v), 24 hr starvation resulted in only a 10% reduction in elimination rate (45 mg/100 ml blood/hr), and did not increase the non-food-deprived rate (49.2 mg/100 ml blood/hr) over that obtained in the above animals' drinking water rather than 5% ethanol. Animals which chronically overdrank ethanol or water for 3 months on a schedule-induced polydipsia procedure, known to result in ethanol physical dependence, showed a decreased rate of ethanol elimination (37.9 mg/100 ml blood/hr for water drinkers) in the non-food-deprived condition. By providing 750 mg of liver powder daily as a food supplement in the ethanol overdrinking regimen, the ethanol elimination rate remained at a rate comparable to the normal animal (48.4 mg/100 ml blood/hr).

Alcohol Drinking↗
PubMed1972

Behavioral maintenance of high concentrations of blood ethanol and physical dependence in the rat.

Rats maintained on an intermittent food schedule with an available ethanol solution drink to excess (13.1 grams of ethanol per kilogram of body weight, daily). Removal of ethanol produces symptoms of physical dependence including death from tonic-clonic seizures. Overindulgence in oral self-administration of an aqueous ethanol solution, resulting in unequivocal physical dependence, approximates a model of human alcoholism.

Alcohol Drinking↗