No abstract

The cellular localization of monoamines in the spinal cord of the mouse and the rat has been studied with the use of a fluorescence method for histochemical demonstration of certain cate‐cholamines and tryptamines in combination with a pharmacological approach and transection experiments. Strong evidence was obtained for the view that noradrenaline (NA) and 5‐hydroxytryptamine (5‐HT) are localized in special systems of nerve tracts which from supraspinal centers descend in the lateral and anterior funiculi to terminate in the gray matter and which belong to monoaminergic neurons. The amines show a massive accumulation in the terminal part of the nerve fibres. This strongly indicates that both amines serve as synaptic transmitters in the spinal cord. Many nerve terminals containing NA or 5‐HT are present in the anterior horns. They are more scarce in the posterior horns. Terminals of both kinds are highly concentrated in the sympathetic lateral column where most—if not all—of the nerve cells are surrounded by them. They originate—at least mainly—from a tract descending in the dorsolateral funiculi. This localization of the descending fibres suggests that they arc identical with the inhibitory fibres going to the sympathetic column.

The reaction under mild conditions between formaldehyde and phenylalanine and phenylethylamine derivatives has been studied. When the amines included in a dried protein film were exposed to formaldehyde vapour a very intense green to yellow fluorescence was give only by those that as well as being primary amines also have hydroxyl groups at the 3 and 4 positions (3,4-dihydroxyphenylalanine, dopamine, noradrenaline). The 3-OH group seems to be esssential for the reaction. The catechol amines, which are secondary amines (adrenaline, epinine), gave a much weaker fluorescence that developed more slowly. The results obtained on further examination of the reaction favour the view that the amines primarily condense with formaldehyde to 1,2,3,4-tetrahydroisoquinolines which are involved in a secondary reaction to become highly fluorescent and at the same time insoluble. This secondary reaction may be a binding to protein, and oxidation with the formation of double bonds in the heterocyclic ring, or both.

SUMMARY The present paper is concerned with an investigation on the site of production of oestrogen in the rat ovary by a method designed to yield more direct evidence than hitherto available. A dissection technique was devised permitting isolation of small cell aggregates from the rat ovary containing only one endocrine cell system. Such cell systems alone or in certain combinations were auto‐transplanted to the anterior chamber of the eye of spayed animals, a contiguous vaginal autotransplant serving as an indicator of the oestrogenic activity of the ovarian grafts. The specificity of this indicator system to oestrogen is discussed. As to the ovarian grafts, only in exceptional cases did they produce systemic hormonal effects, and interference by oestrogenic substances from other sources or by metabolites from steroids released in the grafts was excluded by the appearance of the vagina in situ and a control vaginal transplant in the other eye. The following isolated cell systems were transplanted: interstitial cells, theca interna cells, corpus luteum cells and granulosa cells. All of these cell types were able to survive when grafted. In spite of the complex topography of the rat ovary, it proved possible to secure a certain number of grafts consisting of interstitial cells only or of theca interna cells only. Uncontaminated grafts of granulosa cells and corpus luteum cells could be readily obtained. The dissection technique thus provides a tool for studying ovarian tumours experimentally induced in grafts originally containing only one type of endocrine cells. The transplanted granulosa cells were luteinised and formed cell aggregates of the same histological structure as the normal corpus luteum. The following combinations of cell systems were studied: interstitial cells + corpus luteum cells and theca interna cells + granulosa cells or corpus luteum cells. Secretion of oestrogen was never recorded in transplants of the pure cell systems but only in transplants containing theca interna cells or interstitial cells combined with granulosa cells or corpus luteum cells. The validity of these results is discussed and it is excluded that errors in the experimental method might have caused the negative results with the isolated cell systems. Isolated follicles were not transplanted, but the material permitted an indirect analysis of the oestrogen‐producing capacity of follicles in different developmental stages, showing that this probably arises with the development of the theca interna gland cells. It was found that a single follicle with few theca interna cells could produce a local oestrogenic effect on the indicator epithelium, while a single follicle of preovulatory size and well‐developed thecal gland was able to produce full oestrous reaction of the vagina and uterus in situ. It is concluded from these results that the production of oestrogen is dependant on an interplay between theca interna gland cells or interstitial cells and corpus luteum cells or granulosa cells. The primary source of oestrog...

BJORKLUND, A., L. CEGRELL, B. FALCK, M. R I T Z~N and E. ROSENGREN. Dopaminecontaining cells in sympathetic ganglia. Acta physiol. scand. 1970. 78. 334-338.In addition to noradrenaline (about 1.3-1.5 pg/g) dopamine (about 0.2 pglg) is present in the sympathetic chains of the cat and pig. By means of a recently developed microspectrofluorimetric method, the cellular localization of these two catecholamines has been studied.Dopamine was found in a special type of small, intensely fluorescent cells ("SIF-cells") located among the adrenergic ganglion cell bodies. Most of the dopamine present in the sympathetic ganglia is probably stored in these cells.