Catecholamines potentiate the effect of thyroid hormone on intestinal absorption of glucose in the rat.

The study is to investigate the role of catecholamines on the increased absorption of glucose from the gut by thyroxine, the effect of graded doses of adrenaline and noradrenaline on glucose absorption was studied in euthyroid (ET), hyperthyroid (TH-) and hypothyroid rats (Thx). Glucose absorption was deduced in vivo from intestinal segment perfused with Kreb's bicarbonate solution containing 5.6 mM glucose and in vitro using the everted sac technique. In vivo, basal glucose absorption was significantly increased in the hyperthyroid and decreased in the hypothyroid rats (1.97 +/- 0.19 mM/g, P<0.01, and 0.92 +/- 0.10 mM/g, p<0.05 respectively) when compared with the euthyroid group (1.34 +/- 0.15 mM/g). Adrenaline (20 mg/dl - 80 mg/dl) increased glucose absorption in a dose dependent manner in all the groups. However, the responsiveness of the gut glucose absorption to adrenaline (as evidenced by the dose producing half- maximal absorption or ED50) was reduced by thyroidectomy (ED50 = 26.09 mg/100 ml) and increased by chronic thyroxine treatment (ED50 = 11.13 mg/100 ml). The ED50 in the euthyroid animals was 14.6 mg/100 ml. In vitro, glucose absorption from the isolated segments in both Thx and TH- rats were significantly reduced (P<0.05). Incubation of the isolated intestinal segments with graded doses of adrenaline caused a significan and dose related increases in glucose absorption. However thyroidectomy shifted the dose-response curve for glucose uptake from the isolated intestinal sac incubated with adrenaline to the right of the curve for euthyroid rats. It is concluded that catecholamines may play a role in the increase in intestinal absorption by thyroid hormones.

Alpha subunit and human chorionic gonadotropin in normal pregnancy and gestational trophoblastic disease.

The reported incidence of gestational trophoblastic disease is an order of magnitude higher in Nigeria than in the United States. Sera from a total of 283 pregnant black patients, 138 United States and 148 Nigerian pregnant patients, were analyzed for their serum levels of alpha subunit and human chorionic gonadotropin (hCG). The patterns of hCG secretion were similar in the two populations during normal pregnancy. However, the level of alpha subunit was persistently higher in Nigerian women than in comparable pregnant United States patients. A statistically significantly higher alpha subunit level in the Nigerian patients was found only in the ten- to 13-week gestational period (P less than .005). The higher level of alpha subunit in pregnancy in Nigerian women may signal a population of trophoblastic cells which may be at higher risk for malignancy development in the Nigerian woman.

Effect of antihistamines on anaphylactoid oedema in rats using a modified plethysmometer for measuring foot volume.

This study reports the quantitative effect of the H1--and H2--receptor antagonists on dextran-induced anaphylactoid oedema in rats. The findings indicate that mepyramine, promethazine and chlorpromazine which are H1--receptor antagonists significantly inhibited this anaphylactoid oedema. While on the other hand burimamide an H2--receptor antagonist at doses below 500 micrograms/kg inhibit dextran-induced oedema but at higher doses enhances oedema formation in the test rats. E.D50 values obtained for mepyramine, chlorpromazine and promethazine are 5.01 mg/kg, 0.36 mg/kg, 1.78 mg/kg respectively. The dual effects of burimamide on dextran-induced oedema merits further investigation and confirmation with the aid of other H1--and/or H2--receptor systems. A modification of the plethysmometric method of Buttle et. al. (1957) is also described.

Inactivation of prostaglandin E2 in the stomach of pregnant and oestrogen pretreated rats.

The stomach of pregnant and oestrogen pretreated female rats were found to inactivate significantly exogenous PGE2 when administered orally. The mean basal acid output of pregnant and oestrogen pretreated female rats were also diminished by oral infusion of PGE2. Though the exact mechanism for these phenomena cannot be readily seen from this work, it is suggested that metabolites of PGE2 may be responsible for the acid lowering and ulcer ameliorating effects of PGE2.

Comparative studies on starvation - and indomethacin - induced ulcerations in albino rats.

Experimental models of chronic and acute peptic ulcerations were produced in the albino rats by means of prolonged starvation and indomethacin administration. In the case of acute indomethacin-induced peptic ulceration, the effects of anticholinergic drugs on the ulcers produced were also studied. Starving the rats for a period of seven days produced gastric ulceration in all the rats used while indomethacin produced gastric ulceration within five hours in all the rats used. Severe ulceration of the degree found in human peptic ulcer disease was produced only by chronic starvation. Anticholinergic drugs ameliorated indomethacin-induced gastric ulceration, partly at least, by reducing intra-gastric acidity.

Cow's urine poisoning in Nigeria: cardiorespiratory effects of cow's urine in dogs.

"Cow's urine" concoction (CUPR) is a traditional remedy for convulsive seizures in Nigeria. Its administration has been associated with severe poisoning, sometimes with a fatal outcome in Nigerian children. Recently, we showed that several of the components of the concoction are toxic. We have demonstrated in the present study certain cardio-respiratory effects of cow's urine concoction in dogs. On the cardiovascular system, an initial bradycardia followed by tachycardia and a biphasic effect on blood pressue characterized by a fall followed by a rise were demonstrated. Progressive hypotension following repreated administration of CUPR was also shown in all experimental dogs. On the respiratory system, a short period of respiratory arrest and/or respiratory depression, followed by tachyponoea with associated hypoventilation of the lungs, were observed. The possible explanations for the observed cardiorespiratory effects of the concoction were discussed. On the basis of our findings, an hypothesis is advanced for the possible mechanisms of the neurological sequelae and/or death following cow's urine poisoning.

Immunogenicities of haemocyanins from the giant African snail (Achatina fulica) and the keyhole limpet (Megathura crenulata).

1. The immunogenicities of the giant African snail (Achatina fulica) haemocyanin (AFH) and the keyhole limpet (Megathura crenulata) haemocyanin (KLH) were compared by determining their capacities to induce humoral and cell-mediated immune response in rats. 2. KLH was found to be more immunogenic than AFH, and this was attributed to the fact that KLH contains more moieties, and probably more antigenic determinants than AFH. 3. Since AFH was found capable of stimulating both humoral and cell-mediated immunity, it was suggested that it could be used as an antigen for the investigation of immune responses.

Cow's urine poisoning in Nigeria. Experimental observations in mice.

The method of preparation and administration of "cow's urine" and the signs and symptoms of cow's urine poisoning have been described. Experimental investigations were carried out in mice to assess the toxicity ot this concoction. Effect of the preparation was compared with that of pure nicotine. The effect of each component used in preparing the concoction was also tested. Results of the experiments show that both "cow's urine" and nicotine cause excitement in low doses and cause convulsion and/or death in higher doses. Both also depress respiration. The role of "cow's urine" toxicity following administration to patients with convulsion and the possible aetiology of the neurological sequelae of "cow's urine" poisoning are discussed.