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J J Teal

Publications and source records attributed to J J Teal.

9 recordsLinked to original sources
PubMed1988

Alkane-induced edema formation and cutaneous barrier dysfunction.

Certain mineral oils and hydrocarbons require repeated topical application to cause irritation. A structure activity relationship of pure n-alkanes was undertaken in a mouse ear edema model to investigate the mechanism of cumulative irritancy. Alkanes were applied twice daily over a 4-day period. Dodecane was found to be non-irritating, while tridecane elicited a response only at 96 h. Tetradecane was the strongest irritant with significant increases (p less than 0.05) in ear thickness observed at 48 h. Hexadecane, octadecane, and eicosane exhibited progressively decreasing activity. Permeability of the ears to hydrocortisone was monitored in vitro during tridecane- and tetradecane-induced irritation. Significant increases in permeability were observed 24 h before edema formation. A positive correlation was found between the extent of edema formation and enhancement of permeability. Loss of barrier function would result in increased cutaneous availability of the alkanes. Increased permeability prior to edema formation indicates that induction of barrier dysfunction may be a factor in the mechanism of alkane-induced irritation.

Alkanes↗
PubMed1986

A system for assessing toxicity of chemicals by continuous monitoring of homecage behaviors.

A noninvasive system is described for continuous recording of behaviors in the home cages of rats. Commercially available mesh cages were used so as to conform with housing conditions in most toxicological studies. A minicomputer controlled environmental lighting and recorded eating, drinking, rearing, and horizontal activity. The system's sensitivity was comparable to more complex systems. Validity was demonstrated through manipulation of environmental lighting, food deprivation, and the effects of amphetamine, scopolamine, ethanol, methylscopolamine, triethyltin, and trimethyltin. Advantages over other systems are practicality, economy, the simultaneous analyses of several naturalistic behaviors of individual rats, and the quantification of diurnal rhythms.

Amphetamine↗
PubMed1982

Effects of DDAVP, a vasopressin analog, on delayed matching behavior in the pigeon.

Five pigeons were tested in a delayed matching-to-sample task after receiving an acute injection of DDAVP (1-desamino-8-D-arginine), scopolamine or d-amphetamine. A feeding test also was used to document non-specific drug effects. Scopolamine produced a marked dose-related decrement in accuracy of matching, regardless of delay, indicating that scopolamine impairs both discrimination and short-term memory. Neither DDAVP nor d-amphetamine produced consistent changes in delayed matching. Thus, an experimental model of short-term memory with pigeons did not confirm the findings of others of a positive effect of DDAVP upon cognitive performance in humans.

Animals↗
PubMed1980

Discriminative stimulus effects of prototype opiate receptor agonists in monkeys.

This study was performed to clarify the apparent differences in the cellular substrates mediating the discriminative stimulus effects of morphine and cyclazocine. Squirrel monkeys trained to discriminate between i.m. injections of saline and either morphine (3.0 mg/kg) or cyclazocine (0.1 mg/kg) in a two-choice avoidance paradigm were tested for stimulus generalization to ethylketocyclazocine and SKF 10,047, proposed agonists of receptors mediating the effects of cyclazocine. Both drugs completely mimicked the stimulus effects of cyclazocine but not those of morphine. Naltrexone (0.3 mg/kg) produced a 3-fold shift to the right of the cyclazocine dose-response curve but did not completely block the cyclazocine-like stimulus effects of either SKF 10,047 or ethylketocyclazocine. SKF 10,047 was a competitive antagonist at the receptors mediating the stimulus effects of morphine. These data are consistent with a multiple opiate receptor model, and provide further evidence that the stimulus effects of morphine and cyclazocine are subserved by different cellular substrates.

Animals↗
PubMed1980

Stimulus effects of morphine in the monkey: quantitative analysis of antagonism.

The ability of narcotic antagonists to block the discriminative stimulus effects of 3.0 mg/kg (IM) of morphine was evaluated quantitatively in the squirrel monkey using a two-choice discrete-trial avoidance paradigm. The time-course and relative potency of naloxone and naltrexone for antagonizing morphine's stimulus effects in the squirrel monkey was similar to those determined in rats and pigeons. Complete blockade of morphine's effects was attained with 0.03 mg/kg of either antagonist when given simultaneously with morphine, but only naltrexone completely blocked the stimulus effects of morphine when the pretreatment interval was extended to 12 and 18 hr. A Schild plot derived from the degree of antagonism of graded doses of morphine by graded doses of naltrexone (0.003-0.1 mg/kg) yielded a line with a slope of -0.63 +/- 0.2 and an apparent pA2 value of 8.25 +/- 0.2. These results demonstrate the feasibility of quantitatively assessing the drug-receptor interactions that subserve the discriminative stimulus effects of morphine in the squirrel monkey.

Animals↗