Spontaneous Erythroid Leukemia in a 7-Week-Old Crl:CD (SD) Rat

A young male Crl:CD (SD) rat with erythroid leukemia that presented with emaciation, abdominal distension and a pale visible mucosal membrane was euthanized at 7 weeks of age. At necropsy, enlargement of liver, spleen and pancreatic lymph node was noted. Analysis of blood smear samples revealed many mono- or binucleated erythroblasts that had PAS-positive vacuoles in the cytoplasm. Histopathologically, neoplastic proliferation of atypical cells was observed in the hepatic sinusoids, splenic red pulp, bone marrow, pancreatic lymph node, kidney and lung. Neoplastic cells showed a round to spindle shape, and some neoplastic cells had deeply stained small nuclei and small cytoplasms and resembled erythroblasts. Immunohistochemically, many neoplastic cells were positive for hemoglobin. To our knowledge, this is the first report of erythroid leukemia in a rat of this age. The observed features were similar to those of pure erythroid leukemia in humans

Persistence of Acquired Epileptogenesis in Amygdaloid-Kindled Rats: Relationship between the Initial Kindling Stages and Seizure Development in Rekindling

In order to gain insight into mechanisms underlying the persistence of the partial kindling effect, we suspended amygdaloid kindling at different seizure stages in rats, and investigated the effects on subsequent rekindling after a rest period of 2 months. Ten-week-old rats, implanted with bipolar electrodes, were separated by various initial kindling stages into 5 groups of rats, partially kindled to stages 1 (n = 7) and 2 (n = 10), fully kindled to stages 4 (n = 11) and 5 (n = 11), and control rats (n = 12) which were implanted but not stimulated initially. The number of stimulations required to elicit the first stage 5 seizure during rekindling was significantly lower in the fully kindled groups (P < 0.01 in the stage 4 group and P < 0.001 in the stage 5 group) than the control group. The cumulative afterdischarge duration during rekindling was significantly shorter in the fully kindled groups (P < 0.01 in both groups) than the control group. The latency of the first stage 5 seizure during rekindling was significantly shorter in the partially and fully kindled groups than the control group. These results suggest that epileptogenesis acquired at the partially kindled stage is different than that acquired at the fully kindled stage. However, the effects of the initial kindling on the latency to produce the stage 5 seizure during rekindling persisted both in the partially and fully kindled rats

Effect of Repetitive Glucose Spike and Hypoglycaemia on Atherosclerosis and Death Rate in Apo E-Deficient Mice

Epidemiological data suggest that postprandial hyperglycaemia and hypoglycaemia are potential risk factors for cardiovascular disease. However, the effects of repetitive postprandial glucose spikes, repetitive hypoglycaemia, and their combination on the progression of atherosclerosis remain largely unknown. The present study investigated the effects of rapid rises and falls in glucose, and their combination, on the progression of atherosclerosis in apolipoprotein (apo) E-deficient mice. In this study, apo E-deficient mice with forced oral administration of glucose twice daily for 15 weeks were used as a model of repetitive postprandial glucose spikes, and apo E-deficient mice given an intraperitoneal injection of insulin once a week for 15 weeks were used as a model of repetitive hypoglycaemia. In addition, we established a model of both repetitive postprandial glucose spikes and hypoglycaemia by combining the above interventions. Atherosclerosis was evaluated in all mice by oil red O staining. Administration of ipragliflozin, a selective inhibitor of sodium-glucose cotransporter 2, in the mouse model of repetitive glucose spikes inhibited the progression of atherosclerosis, whereas long-term repetitive glucose spikes, repetitive hypoglycaemia, and their combination had no significant impact on atherosclerosis. However, repetitive hypoglycaemia was associated with poor survival rate. The results showed that repetitive hypoglycaemia reduces the survival rate without associated progression of atherosclerosis in apo E-deficient mice