[The effect of kryptopyrrole on the brain-activity of cats: a quantitative EEG-analysis (author's transl)]. / Die Wirkung von Kryptopyrrol auf das Gehirn der Katze: eine quantitative EEG-Analyse.

Continuing earlier investigation Z. EEG-EMG, 1976, 7, 151-156 the authors have studied the electrical activity of the cortex and subcortical regions elicited by stimulating mesencephalic reticular formation, after injection i.p. of Kryptopyrrole. The changes of activity was tape recorded and subjected to an off-line computer analysis with the method of Fast Fourier. Power spectral densities as well as auto and cross correlograms were calculated. The threshold for desynchronisation following stimulation shows a characteristic form due to the effect of Kryptopyrrole: after temporary decrease there is a marked increase. After stimulation the effect on subcortical structures in strikingly different from that of the cortex.

[The effects of kryptopyrrole on the brain of cats in the quantitative EEG-analysis (author's transl)]. / Quantitative EEG-untersuchungen über die Wirkung von Kryptopyrrol auf das Gehirn der Katzen

A frequency analyzer and a biointegrator were used to study the effect of kryptopyrrole (20, 60 or 90 mg/kg) on the cortical and various subcortical structures in cat experiments. It was found that, as regards the subcortical structures, kryptopyrrole primarily causes significant bioelectric changes in the regions of the hippocampus and amygdala; its effects in the cortex are much less marked. In the second hour of the experiment, excitation appears in the behaviour of the cats, simultaneously with an increase in area of the slow frequency regions, where-as after 4-5 hours a considerable behaviour-inhibition can be observed simultaneously with a decrease in area of the slow wave range. The experimental data confirm the behaviour-active effect of kryptopyrrole. The findings indicate that the effect of kryptopyrrole is exerted in two phases. The neurophysiological data obtained give an explanation for these contradictory behaviour changes.

Effects of kryptopyrrole on porphyrin synthesis in Bacillus subtilis 168.

We investigated the effects of exogenous 5-aminolaevulinate and kryptopyrrole, separately and together, on the porphyrin synthesis of Bacillus subtilis 168. It was confirmed that 5-aminolaevulinate increases the porphyrin content of the culture fluid in the way previously described. In comparison with the basic activity of the bacteria, kryptopyrrole enhances the amount of extracellular copro III, uro III and 5-carboxyl porphyrins. The combination of 5-aminolaevulinate and kryptopyrrole enhances the porphyrin synthesis; moreover, a more pronounced increased in porphyrin synthesis occurs if the kryptopyrrole solution used is rich in its oxidation products. In this latter case, the amount of 5,6,7-carboxylic porphyrins increases markedly along with uro III and particularly copro III, while suburoporphyrins also makes their appearance. An hypothesis is advanced to explain tentatively the increase in the porphyrin synthesis provoked by kryptopyrrole.