Prostaglandins E and F in the central nervous system : a quantitative localisation study following various drug treatments
Section I in the investigation of prostaglandin E and prostaglandin F levels in cerebrospinal fluid of conscious cats during bacterial pyrogen-induced fevers. Two types of febrile response were found following intravenous injection of Shigella dysenteriae. Upon initial exposure to pyrogen, fevers of long latency were observed with no significant increase in either PGE or PGF levels. Upon subsequent exposure to pyrogen, short latency fevers were observed with significant increases of both PGE and PGF levels which paralleled the increases in deep body temperature, and these results are compatible with both prostaglandins E and F having a role in this type of pyrogen-induced fever. Section II involves the development and application of an immunohistochemical localisation technique for prostaglandin E₂ and prostaglandins of the Fα series in formalin-fixed, paraffin-embedded albino rat brain. The prostaglandin levels following various drug treatments were quantitated using microdensitometry. Three areas of rat brain were chosen for investigation; the caudate nucleus, the medial forebrain bundle and the hypothalamus. Amphetamine and morphine increased, chlorpromazine and indomethacin decreased, and atropine and chloral hydrate did not significantly alter PGE₂ or PGFα series levels in the three areas studied. The effects of these drugs on prostaglandin levels are discussed in relation to documented cholinergic, dopaminergic, noradrenergic and serotonergic neuronal systems. Correlations between drug effects, prostaglandin levels and thermoregulation, when present, are described.