Nucleotide metabolism was studied in rats during and following the induction of 10 min of forebrain ischemia (four‐vessel occlusion model). Purine and pyrimidine nucleotides, nucleosides, and bases in forebrain extracts were quantitated by HPLC with an ultraviolet detector. Ischemia resulted in a severe reduction in the concentration of nucleoside triphosphates (ATP, GTP, UTP, and CTP) and an increase in the concentration of AMP, IMP, adenosine, inosine, hypoxanthine, and guanosine. During the recovery period, both the phosphocreatine level and adenylate energy charge were rapidly and completely restored to the normal range. ATP was only 78% of the control value at 180 min after ischemic reperfusion. Levels of nucleosides and bases were elevated during ischemia but decreased to values close to those of control animals following recirculation. Both the decrease in the adenine nucleotide pool and the incomplete ATP recovery were caused by insufficient reutilization of hypoxanthine via the purine salvage system. The content of cyclic AMP, which transiently accumulated during the early recirculation period, returned to the control level, paralleling the decrease of adenosine concentration, which suggested that adenylate cyclase activity during reperfusion is modulated by adenosine A2 receptors. The recovery of CTP was slow but greater than that of ATP, GTP, and UTP. The GTP/GDP ratio was higher than that of the control animals following recirculation.

A patient with familial idiopathic hypoparathyroidism whose major symptoms were paroxysmal kinesigenic choreoathetosis (PKC) and paroxysmal dystonic choreoathetosis (PDC) was reported. CT revealed marked calcification in the basal ganglia, the thalamus and the dentate nucleus of cerebellum. Positron emission tomographic (PET) study showed decreased glucose metabolism in the basal ganglia and thalamus. The paroxysms were eliminated by the normalization of serum calcium level. Thus the paroxysms seemed to be induced by hypocalcemia which stimulated the lesions in the basal ganglia and thalamus, on one occasion, as in PKC, and on the other occasion, as in PDC. Concomitant occurrence of both PKC and PDC in a patient is unique and is of interest in considering the pathomechanisms of these different but related disorders.paroxysmal kinesigenic choreoathetosis (PKC) ; paroxysmal dystonic choreoathetosis (PDC) ; familial idiopathic hypoparathyroidism Idiopathic hypoparathyroidism is a rare disorder often presenting neurological symptoms including epileptic seizures, tetany, sensory disturbances, cerebellar and extrapyramidal signs (Simpson 1952). Paroxysmal choreoathetosis, on the other hand, is also a rare disorder of which pathological mechanisms are poorly understood (Lance 1977). It has been divided into two types, paroxysmal kinesigenic choreoathetosis (PKC) (Kertesz 1967;Plant 1983) and paroxysmal dystonic choreoathetosis (PDC) (Mount and Reback 1940;Richards and Barnett 1968;Lance 1977). We had the opportunity to study a young woman with familial idiopathic hypoparathyroidism in which major symptoms were concomitant PKC and PDC. Thus far, it has been emphasized that PKC and PDC are different clinical entities. Our case is of interest because concomitant occurrence of both PKC and PDC is not known. Possible mechanisms of the secondary paroxysmal choreoathetoses in this patient is discussed.

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