Autoradiographic measurement of tyrosine hydroxylase immunoreactivity in rat brain using enhanced chemiluminescence: a general method for combined quantitative and cytochemical detection.

Autoradiographic measurements of peroxidase labelled tyrosine hydroxylase immunoreactivity in brain sections from rats with unilateral 6-hydroxydopamine lesions were obtained using enhanced chemiluminescence. The autoradiograms required only 5-60 s exposure and displayed a good signal-to-noise ratio. The autoradiograms were quantitated using densitometry and by comparison with a standard curve. Following acquisition of the autoradiograms the sections were stained with the chromogen diaminobenzidine (DAB). Distribution of the DAB closely followed the grain densities observed in the autoradiograms on both the lesioned and unlesioned side of the brain. This method represents a simple, rapid and inexpensive technique for performing both quantitative autoradiography and cytochemical studies in individual tissue sections of any peroxidase labelled immunoreactivity.

Long-term sensitization of apomorphine-induced rotation behavior in rats with dopamine deafferentation or excitotoxin lesions of the striatum.

Following unilateral 6-hydroxydopamine (6-OHDA)-induced deafferentation or unilateral kainic acid (KA) lesions of the striatum, rats displayed rotation behavior in response to apomorphine (0.25 or 1 mg/kg, SC, for 6-OHDA- and KA-lesioned rats, respectively). Three days following the initial apomorphine injection, rats were challenged under identical conditions with the same dose of apomorphine received previously. A third trial with apomorphine was again repeated after 3 days. Two more sets of behavioral data, each consisting of three trials, were collected under the same conditions as the first. Each set was separated by a period of 5-6 weeks. Following the second trial of the first set, rats showed a significant increase in the maximal number of rotations, demonstrating behavioral sensitization. Following the two 5-week intervals, rats were still sensitized to apomorphine, showing behavioral responses similar to the sensitized. Following the two 5-week intervals, rats were still sensitized to apomorphine, showing behavioral responses similar to the sensitized responses observed after the initial trials. Thus, the postsynaptically mediated sensitization of apomorphine-induced rotation behavior in 6-OHDA- or KA-lesioned rats is a long-lasting phenomenon. That lesions producing postsynaptic dopaminergic hypersensitivity and hyposensitivity can both show long-lasting sensitization may indicate multiple mechanisms underlying the sensitization.

Sensitization of c-fos expression in rat striatum following multiple challenges with D-amphetamine.

D-Amphetamine transiently stimulates the expression of the immediate-early response gene, c-fos, in rat striatal cell nuclei. D-Amphetamine (2.5 mg/kg i.p.) induced a significantly greater expression of Fos-like immunoreactivity in striatum of rats treated three days previously with D-amphetamine compared to rats treated three days previously with saline. This increase in the expression of Fos-like immunoreactivity in rat striatum was characterized by a significantly greater number of immunoreactive nuclei and a significant increase in the intensity of the immunoreactivity. This sensitization of c-fos expression following a repeated administration of D-amphetamine indicates an increased activation of post-synaptic elements in rat striatum.

Metabolic changes in the rat liver during pregnancy. II. Tricarboxylic acid cycle.

During pregnancy the rat liver shows alterations in metabolism which apparently do not to occur in the non-pregnant animal. In our study, the following metabolite concentrations and enzyme activities in the liver of pregnant and non-pregnant rats were measured after fasting periods of 6 and 12 h: malate, fumarate, isocitrate, alpha-keto-glutarate, glutamate, malate-dehydrogenase, fumarate-hydratase, glutamate-dehydrogenase, isocitrate-dehydrogenase, aspartate-aminotransferase and after 12 h fast, the concentrations of acetyl coenzyme A and citrate. These results are discussed with regard to their possible importance for the maternal and fetal energy supply.